Document:

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                                                                     Exhibit 4.2

                             STOCKHOLDERS' AGREEMENT

      This Stockholders' Agreement (the "Agreement") is made as of the 11th day
of October 1999 by and among Regeneration Technologies, Inc., a Florida
corporation (the "Company"), the investors set forth on Exhibit A to the
Purchase Agreement (as defined below) (the "Class C Investors"), the
stockholders listed on Exhibit A hereto (the "Class B Investors"), the
stockholders listed on Exhibit B hereto (the "Class A Investors"), and the
stockholders listed on Exhibit C hereto (the "Listed Stockholders"), with the
Class C Investors, the Class B Investors, the Class A Investors and the Listed
Stockholders sometimes being referred to herein as the "Stockholders," and the
Class C, Class B and Class A Investors sometimes being referred to herein as the
"Preferred Stockholders."

      WHEREAS, the Class A Investors own in the aggregate 1,777,348 shares of
the Class A convertible Preferred Stock of the Company, par value $0.001 per
share (the "Class A Preferred Stock");

      WHEREAS the Class B Investors own in the aggregate 748,152 shares of Class
B Convertible Preferred Stock of the Company, par value $0.001 per share (the
"Class B Preferred Stock");

      WHEREAS, the Listed Stockholders own the number of shares of the Common
Stock of the Company, par value $0.001 per share (the "Common Stock") set forth
on Exhibit C hereto;

      WHEREAS, concurrently with the execution of this Agreement, the Class C
Investors are purchasing shares of the Class C Convertible Preferred Stock of
the Company, par value $0.001 per share (the "Class C Preferred Stock"),
pursuant to that certain Class C Preferred Stock and Warrant Purchase Agreement
of even date herewith (the "Purchase Agreement");

      WHEREAS, the Stockholders desire to provide for representation on the
Board of Directors of the Company in the manner set forth below; and

      WHEREAS, the Preferred Stockholders desire to provide for certain
preemptive, co-sale and first offer rights.

      In consideration of the premises and mutual covenants contained herein and
the consummation of the sale and purchase of shares of Class C Preferred Stock
of the Company pursuant to the Purchase Agreement, and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

1. Voting.

      (a) Election of Directors. Subject to the special provisions of Sections
1(b) and 2 below, at any time at which the stockholders of the Company will have
the right to vote for, or will vote for, or consent in writing to, the election
of directors of the Company, each Stockholder

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hereby agrees to vote or cause to be voted all Shares (as defined herein below)
owned or hereafter acquired by him, her or it, or over which he, she or it has
voting control, so as to fix the number Of directors of the Company at seven (7)
and in favor of the following actions:

      (i)   to cause and maintain the election to the Board of Directors of two
            (2) designated representatives of the holders of shares of Class A
            Preferred Stock, by action of a majority of the Shares of Class A
            Preferred Stock held by such stockholders voting as a separate class
            (individually, a "Class A Preferred Director" and collectively, the
            "Class A Preferred Directors");

      (ii)  to cause and maintain the election to the Board of Directors of two
            (2) designated representatives of the holders of shares of Class B
            Preferred Stock, by action of a majority of the Shares of Class B
            Preferred Stock held by such stockholders voting as a separate class
            (individually, a "Class B Preferred Director" and collectively, the
            "Class B Preferred Directors");

      (iii) to cause and maintain the election to the Board of Directors of one
            (1) designated representative of the holders of shares of Common
            Stock or their designees, by action of a majority of the shares of
            Common Stock voting as a separate class (the "Common Stock
            Director");

      (iv)  to cause and maintain the election to the Board of Directors of one
            (1) designated representative of the holders of shares of Common
            Stock, Class A Preferred Stock, Class B Preferred Stock, and Class C
            Preferred Stock, by action of a majority of the shares of Common
            Stock, Class A Preferred Stock, Class B Preferred Stock, and Class C
            Preferred Stock, voting together as a class (the "Stockholder
            Director"); and

      (v)   to cause and maintain the election to the Board of Directors of the
            Chief Executive Officer of the Company (the "CEO Director").

      The current Class A Preferred Directors shall be Peter F. Gearen and
Daniel Weber. The current Class B Preferred Directors shall be Michael J. Odrich
and Philip R. Chapman. The current Common Stock Director shall be Anthony C.
Phillips. The current Stockholder Director shall be E.R. Pickard ("Pickard").
The current CEO Director shall be James M. Grooms.

      Until such time as Medtronic shall elect otherwise by giving written
notice of such election to the Company (the "Medtronic Election"), the holders
of shares of Common Stock, Class A Preferred Stock, Class B Preferred Stock and
Class C Preferred Stock hereby agree that they shall vote, or cause to be
voted, their respective shares so as to designate Pickard as the Stockholder
Director.

      The "Shares" shall mean and include any and all shares of Common Stock and
shares of capital stock of the Company by whatever name called, the shares of
Class A Preferred Stock, the shares of Class B Preferred Stock, and the shares
of Class C Preferred Stock, which carry voting rights (including voting rights
which arise by reason of default) and shall include any

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shares now owned or subsequently acquired by a Stockholder, however acquired,
including, without limitation, stock splits and stock dividends. For purposes of
this Section 1, the Class A Preferred Stock, the Class B Preferred Stock, and
the Class C Preferred Stock shall include any shares of Common Stock into which
such Preferred Stock is converted.

      The company shall cause the nomination for election to the Board of
Directors of the designated representatives and shall call such stockholders'
meetings as may be necessary to elect any such election. The Stockholders shall
not vote their Shares in favor of the election of directors except as specified
in this Section 1.

      (b) Vacancies and Removal. Each of the directors designated pursuant to
Section[ILLEGIBLE] shall be elected at any annual or special meeting of
stockholders (or by written consent in lieu of a meeting of stockholders) and
shall serve until his successor is elected and qualified or until the earlier of
his death, resignation or removal.

            (i) The Stockholders shall vote all their Shares to cause a Class A
Preferred Director removed during his term of office, when, and only when, they
are so directed in writing by the holders of a majority of the shares of Class A
Preferred Stock.

            (ii) The Stockholders shall vote all their Shares to cause a Class B
Preferred Director to be removed during his term of office, when, and only when,
they are so directed in writing by the holders of a majority of the shares of
Class B Preferred Stock.

            (iii) The Stockholders shall vote all their Shares to cause the
Common Stock Director to be removed during his term of office, when, and only
when, they are so directed in writing by the holders of a majority of the shares
of Common Stock.

            (iv) The Stockholders shall vote all their Shares to cause the
Stockholder Director to be removed during his term of office, when, and only
when, they are so directed in writing by the holders of a majority of the shares
of Common Stock, Class A Preferred Stock, Class B Preferred Stock, and Class C
Preferred Stock, voting together as a class.

            (v) The Stockholders shall vote all their Shares to cause the CEO
Director to be removed during his term of office, when, and only when, such
individual no longer serves as Chief Executive Officer of the Company.

            In the event of any vacancy in the position of any of the directors
elected pursuant to Section 1(a), the Company agrees to promptly nominate, and
the Stockholders agree to promptly vote their Shares, to elect such person as
has been nominated to fill such position by the respective groups set forth in
Section 1(a) or in the case of the CEO Director, the person then serving as
Chief Executive Officer of the Company.

      (c) Observation Rights.

            (i) Observation Rights of Stephens. The Company agrees that Stephens
Regeneration LLC ("Stephens") may, for so long as it is a holder of at least 25%
of the

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shares of Class C Preferred Stock originally issued to Stephens by the Company,
from time to time, appoint a representative to attend meetings of the Board of
Directors of the Company or any committees thereof as an observer (the
"Observer"). The Observer is not entitled to vote on any matters before the
Board of Directors or any committees thereof. Subject to the confidentiality
provisions set forth below, neither Stephens nor the Observer shall have any
duties, responsibilities or liability by virtue of attendance at such meetings
or the failure to attend the samee. The Company shall notify the Observer of all
Board of Directors meetings at the same time as the Company notifies Directors
of such meetings and the Observer shall be entitled to all written materials
Directors are entitled to receive. Except as required by law, the Observer shall
not disclose or use any Confidential Information (as defined below) furnished to
the Observer to any person other than Stephens or its advisors. For purposes of
this Section 1(c), "Confidential Information" means any information, whether or
not in writing, regarding the parties to this agreement or their affiliates or
any transactions or matters before the Board of Directors or any committees
thereof. Confidential Information does not include information that the Observer
can demonstrate (i) is generally available to or known by the public other than
as a result of an improper disclosure; or (ii) is obtained by the Observer from
a source other than the Company or the Board of Directors or any committees
thereof.

            (ii) Observation Rights of Medtronic. The Company agrees that
Medtronic Asset Management, Inc. ("Medtronic") or any of its affiliates may, for
so long as Medtronic or such affiliate, as the case may be, is a holder of at
least 25% of the shares of Class C Preferred Stock originally issued to
Medtronic by the Company, from time to time, appoint an Observer, who shall be
bound by the confidentiality provisions of Section 1(c)(i) above. The Observer
is not entitled to vote on any matters before the Board of Directors or any
committees thereof. Subject to the confidentiality provisions set forth above,
neither Medtronic nor the Observer shall have any duties, responsibilities or
liability by virtue of attendance at such meetings or the failure to attend the
same. The Company shall notify the Observer of all Board of Directors meetings
at the same time as the Company notifies Directors of such meetings and the
Observer shall be entitled to all written materials Directors are entitled to
receive. Notwithstanding the foregoing, until such time as Medtronic shall
exercise the Medtronic Election 1(c)(ii). Medtronic shall not have the right to
appoint an Observer pursuant to this Section

      (d) Notice. The Company shall provide the Stockholders with prior written
notice of any intended mailing of notice to stockholders for a meeting at which
directors are to be elected, and each of the groups set forth in Section 1(a)
shall notify the Company in writing, prior to such mailing, of the persons
designated by such group as nominees for election as directors. If a group shall
fail to give notice to the Company as provided above, it shall be deemed that
the designees of such group, as the case may be, then serving as directors shall
be their designees for reelection.

2. Preemptive Rights.

      (a) The Company hereby grants to each of the Preferred Stockholders a
preemptive right to purchase, on a pro rata basis, all or any part of New
Securities (as defined below) that the

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Company may, from time to time, propose to sell and issue, subject to the terms
and conditions set forth below. Each Preferred Stockholders' pro rata share, for
purposes of this subsection 2(a), equal a fraction, the numerator of which is
the aggregate number of shares of Common Stock then held by the Preferred
Stockholders or issuable upon conversion or exercise of any shares, convertible
securities, options, rights or warrants then held by the Preferred Stockholders,
and the denominator of which is the total number of shares of Common Stock then
held by the Preferred Stockholders plus the number of shares of Common Stock
issuable upon conversion or exercise of then outstanding Shares, convertible
securities, options, rights or warrants, then held by the Preferred
Stockholders.

            (b) "New Securities" shall mean any capital stock of the Company
regardless of either now authorized, and rights, options or warrants to purchase
capital stock, and securities of any type whatsoever which are, or may become,
convertible into capital stock; provided, however, that the term "New
Securities" does not include (i) the shares issuable under the Purchase
Agreement, (ii) shares of Common Stock issuable upon conversion of the Class A
Preferred Stock, the Class B Preferred Stock, or the Class C Preferred Stock;
(iii) securities offered to the public pursuant to a Registration Statement;
(iv) securities issued for the acquisition of another corporation by the Company
by merger, purchase of substantially all the assets of such corporation or other
reorganization resulting in the ownership by the Company of not less than 51% of
the voting power of such corporation; (v) up to 400,000 shares of Common C)
Stock issued to employees or consultants of the Company or UFTB pursuant to a
Board-approved stock option plan, employee stock purchase plan, restricted stock
plan or other employee stock plan or option agreement; (vi) securities issued as
a result of any stock split, stock dividend or reclassification of Common Stock,
distributable on a pro rata basis to all holders of Common Stock; (vii) shares
of Common Stock issuable upon the exercise of any warrant issued by the Company
prior to or as of the date hereof, including Common Stock Warrants issued to
each of Stephens and Medtronic in connection that certain Convertible Class C
Preferred Stock and Warrant Purchase Agreement of even date herewith; or (viii)
any shares of stock of the Company to be issued in connection with the
acquisition by the Company of Georgia Tissue Bank, Inc.

            (c) In the event the Company intends to issue New Securities, it
shall give the Preferred Stockholders written notice of such intention,
describing the type of New Securities to be issued, the price thereof and the
general terms upon which the Company proposes to effect such issuance. Each of
the Preferred Stockholders shall have 30 days from the date of any such notice
to agree to purchase all or part of its pro rata share of such New Securities
for the price and upon the general terms and conditions specified in the
Company's notice by giving written notice to the Company stating the quantity of
New Securities to be so purchased. The Preferred Stockholders shall have a right
of oversubscription such that if any Preferred Stockholder fails to purchase all
of its pro rata share of the New Securities, the other Preferred Stockholders,
among them, shall have the right to purchase up to the balance of such New
Securities not so purchased.

            (d) To the extent that the Preferred Stockholders fail to exercise
the foregoing preemptive right with respect to any New Securities within such
30-day period, the Company may Within 90 days thereafter sell any or all of such
New Securities not agreed to be purchased

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by the preferred Stockholders, at a price and upon general terms no more
favorable to the purchaser thereof than specified in the notice given to the
Preferred Stockholders pursuant to paragraph (c) above. In the event the Company
has not sold such New Securities within such 90-day period, the Company shall
not thereafter issue or sell any New Securities without first offering such New
Securities to the Preferred Stockholders in the mariner provided above.

3. Right of First Offer.

      (a) Restrictions on Transfers.

            (i) Except as otherwise provided in subsection 3(b) below, a
Preferred Stockholder or a Specified Common Stockholder (as defined below) shall
sell, assign, transfer, pledge, hypothecate or otherwise dispose of, by
operation of law or otherwise (collectively transfer), any of the Shares, or any
interest therein, only in accordance with the terms of this Section 3. A
"Specified Common Stockholder" shall mean James Grooms, Richard Allen, Frank &
Glowczewskie Jr. and Nancy Holland.

            (ii) Notwithstanding the foregoing, a Preferred Stockholder or a
Specified Common Stockholder may transfer Shares or Common Stock, as the case
may be, to (i) any "affiliate" of such Stockholder (as such term are defined in
the rules and regulations promulgated under the Securities Act), (ii) an
immediate family member of such Stockholder, (iii) in the case of any Preferred
Stockholder that is a partnership, a partner of such partnership or (iv) in the
case :of any Preferred Stockholder that is a corporation, a stockholder of such
corporation, provided that such Shares or Common Stock, as the case may be,
shall remain subject to this Agreement (including without limitation the
restrictions on transfer set forth in this Section 3) and such permitted
transferee shall, as a condition to such transfer, deliver to the Company a
written instrument confirming that such transferee shall be bound by all of the
terms and conditions of this Agreement.

      (b) Receipt and Communication of Offer. Subject to the terms of Section
3(a) hereof if at any time a Preferred Stockholder or Specified Common
Stockholder (the "Selling Stockholder") desires to transfer for cash, cash
equivalents or any other form of consideration (including a promissory note) all
or any part of the Shares or the Common Stock, as the case may be, or any shares
of Common Stock or other capital stock of the Company acquired by such Selling
Stockholder subsequent to the date hereof (such shares of Common Stock and the
Shares are collectively referred to as the "Selling Stockholder Shares"), the
Selling Stockholder shall submit a written offer (the "Offer") to sell the
Selling Stockholder Shares (the "Offered Shares") to the Company and the other
Preferred Stockholders specifying the terms and conditions, including price
pursuant to which the Selling Stockholder proposes to sell such Offered Shares.
The Offer shall disclose the number of Offered Shares proposed to be sold, the
total number of shares of all classes of the Company's capital stock owned by
the Selling Stockholder, the terms and conditions, including price, of the
proposed sale, and any other material facts relating to the proposed sale. The
Offer shall further state that the Company may acquire, in accordance with the
provisions of this Agreement or a Stock Restriction Agreement (as defined
below), as the case may be, all or any portion of the Offered Shares for the
price and upon the other terms and

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conditions including deferred payment (if applicable), set forth therein,
provided, however, that if the purchase price for the Offer is proposed to be
paid, in whole or in part, in securities of a third party, the Company may
instead pay cash based on the fair market value of such securities.

      (c) Company's Right. The Company shall have the absolute right, by
delivery of written notice to the Selling Stockholder (as hereinafter provided),
to repurchase all or a portion of the Offered Shares offered by a Preferred
Stockholder in accordance with the terms of subsection d hereof and of a
Specified Common Stockholder in accordance with the terms of the stock
restriction agreement executed by such Specified Common Stockholder upon
issuance of the shares of Common Stock (the "Stock Restriction Agreement").

      (d) Company Notice of Intent to Repurchase. If the Company desires to
repurchase all or any part of the Offered Shares, it shall communicate in
writing (the "Notification") its election to repurchase to the Selling
Stockholder, which communication shall state the number of Offered Shares the
Company desires to repurchase and shall be delivered in person or by facsimile
to the Selling Stockholder within 25 days of the Offer Date. The Notification
shall, when taken in conjunction with the Offer, be deemed to constitute a
valid, legally binding and enforceable agreement for the sale and repurchase of
such Offered Shares. Sales of the Offered Shares to be sold to the Company
pursuant to this Section shall be made at the offices of the Company no later
than the 60th day following the Offer Date (or if such 60th day is not a
business day, then on the next succeeding business day). Such sales shall be
effected by Selling Stockholder's delivery to the Company of a certificate or
certificates evidencing ownership of the Offered Shares to be repurchased by it,
duly endorsed for transfer to the Company, against payment to the Selling
Stockholder of the repurchase price therefor by the Company.

      (e) Preferred Stockholders' Right. If the Company elects not to exercise
its right to repurchase all the Offered Shares under this Section 3 or under the
terms of the applicable Stock Restriction Agreement, each Preferred Stockholder
shall have the option, but not the obligation, to purchase its pro rata share of
the remaining Offered Shares on the same terms as specified in the Offer. A
Preferred Stockholder's pro rata share, for purposes of this subsection 3(e),
shall equal a fraction, the numerator of which is the number of shares of Common
Stock or Common Stock issuable upon conversion of the Preferred Stock which such
Preferred Stockholder then holds (the "Preferred Stockholder's Stock"), and the
denominator of which is the aggregate number of shares of Preferred
Stockholder's Stock held by all Preferred Stockholders exercising their purchase
rights under this Section 3(e). After the expiration of the 25-day period in
Section 3(d) but within 40 days after the Offer Date, any electing Preferred
Stockholders shall give notice to the Selling Stockholder and the Company
stating whether or not it elects to exercise its option, the number of Offered
Shares, if any, it elects to purchase, and a date and time for consummation of
the purchase not more than 60 days after the Offer Date. Failure by a Preferred
Stockholder to give such notice within such time period shall be deemed an
election by it not to exercise its option. If more than one Preferred
Stockholder exercises its purchase option and the aggregate number of remaining
Offered Shares sought to be purchased by such Preferred Stockholders exceeds the
aggregate number of remaining Offered Shares, the number of remaining Offered
Shares to be purchased by each such Preferred Stockholder shall be pro rated
based on its respective equity interest in the Company on a fully diluted basis.

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      (f) If the aggregate number of Offered Shares that the Company and the
Preferred stockholders elect to purchase is less than all of the Offered Shares,
then the Company and the preferred Stockholder shall not be entitled to purchase
any of the Shares. The Selling older shall thereafter be free to offer all of
the Offered Shares described in the Offer to a party, at a price and on terms no
less favorable to such Selling Stockholder than the price the terms set forth in
the Offer. No less than 15 days prior to consummating a sale to a third (the
"proposed Transferee"), the Selling Stockholder shall give the Company notice of
the identity of the Proposed Transferee. If the Proposed Transferee is a
Competitor of the Company defined below), then the Selling Stockholder may not
consummate the proposed transfer without the approval of the Company. A
"Competitor" shall mean an entity engaged in engineering, processing,
distributing or developing tissue-regeneration products. The Company's approval
shall be deemed to given if the Company has not objected to the transfer within
10 days of its receipt of notification of the identity of the Proposed
Transferee. If the Company has not objected to the sale within such 10-day
period, then the Selling Stockholder shall be free to consummate the sale to the
Proposed Transferee for a period of ninety days commencing on the otermination
of the Company's and the Preferred Stockholders' 40-day period to exercise their
night of First Refusal pursuant to Section 3(d) above.

      (g) Effect of Prohibited Transfer. The Company shall not be required (a)
to transfer on its books any of the Shares or Common Stock, as the case may be,
which shall have been sold or transferred in violation of any of the provisions
set forth in this Agreement, or (b) to neat as owner of such Shares or Common
Stock, as applicable, or to pay dividends to any transferee to whom any such
Shares or Common Stock, as applicable, shall have been so sold or transferred.

      (h) The restrictions of this Section 3 shall not apply to shares of Common
Stock sold in connection with a public offering of shares of the Company's
Common Stock pursuant to an effective registration statement under the
Securities Act (a "Public Offering") and shall terminate in their entirety on
the earliest of (i) the closing of the Company's initial Public Offering or (ii)
the agreement of the Company and all of the Preferred Stockholders.

4. Co-Sale Rights.

      (a) No Specified Common Stockholder or Preferred Stockholder (the "Co-Sale
Stockholder") shall transfer, in any one or more transactions, any shares of
stock now or hereafter held by him, other than as provided in this Section 4,
until (a) he first complies with Section 3, relating to a right of first refusal
inuring to the benefit of the Company and the other Preferred Stockholders, and
(b) thereafter, he notifies each Preferred Stockholder of the proposed
transaction and gives such Preferred Stockholders the opportunity to include in
the sale to the proposed transferee, shares of stock. The aggregate number of
shares of stock that a Preferred Stockholder shall be entitled to have included
in such sale will be that number that upon conversion into Common Stock at the
applicable conversion rate would bear the same proportion oto the total number
of shares of stock proposed to be sold by the Co-Sale Stockholder as the total
Dumber of shares of stock held by the Preferred Stockholder bears to the
aggregate number of `Shares of the Company's Common Stock (calculated on a fully
diluted basis), and each Preferred K

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Stockholder shall be entitled to participate in such number pro rata on the
basis of the number of shares of stock then held by him or it. Each Preferred
Stockholder shall have a period of fifteen (15) days (the "Offer Period"), from
the date notice of such opportunity is received to give the Co-Sale Stockholder
written notice of his or its desire to participate in such sale, stating in such
notice the number of shares desired to be sold; and if no such notice is given
within the Offer Period, such Preferred Stockholder shall be deemed to have
chosen not to participate.

      (b) Notwithstanding the foregoing, the provisions of Section 4(a) shall be
inapplicable to the following transactions:

            (i) A transfer of any or all of a Preferred Stockholder's stock to
an affiliate;

            (ii) A transfer of any or all of a Preferred Stockholder's stock to
its immediate family or to a trust, the beneficiaries of which are exclusively
one or more of the group of persons consisting of the Preferred Stockholder and
members of the Preferred Stockholder's immediate family. "Immediate family" as
used herein shall mean spouse, lineal descendant, father, mother, brother or
sister of the Preferred Stockholder making such transfer;

            (iii) In the case of a Preferred Stockholder that is in the form of
a corporation, limited liability company, or partnership, a transfer of any or
all of a Preferred Stockholder's interest to its stockholders, members or
partners, as the case may be;

            (iv) The sale, assignment or transfer by way of bequest or
inheritance upon death of a Preferred Stockholder;

            (v) The sale, assignment or transfer to the Company pursuant to the
right of first refusal provisions set forth in this Agreement, as they may from
time to time be amended; or

            (vi) Following the consummation of an underwritten public offering
pursuant to the Securities Act, sales pursuant to Rule 144 under the Securities
Act;

provided, that, in the case of a transaction described in clauses (i), (ii) and
(iii) above, any transferee of a Preferred Stockholder shall agree to be bound
by this Agreement and shall so signify in writing.

5. Miscellaneous.

      (a) Termination. This Agreement shall terminate in its entirety on the
earliest to occur of (a) the closing of the Company's first underwritten public
offering of Common Stock in which the per share is at least $54.202 to price
(subject to Adjustment) that results in aggregate net proceeds to the Company
(after deducting underwriting commissions and offering expenses) of not less
than $20,000,000; or (b) mutual agreement is reached by all the parties hereto.

            (b) No Revocation. The voting agreements contained herein are
coupled with an interest and may not be revoked, except by written consent of
all of the Stockholders.

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      (c) Indemnification. Each of the Stockholders agrees not to take any
action to amend either the Company's Articles of Incorporation or its By-Laws,
each only with respect to indemnification of directors, as presently in effect,
without the prior written consent of all of the Stockholders.

      (d) Action as Director. No party hereto who is or may become a director of
the company either agrees or implies that he will exercise his actions as a
director in any manner other than in accordance with his considered judgment at
such time with respect to the best interests of the Company and all of its
stockholders.

      (e) Stock Transfer Record. The Company shall maintain a stock transfer
book in which shall be recorded the name and address of each Stockholder. No
transfer of Shares shall be effective or valid unless and until recorded in such
stock transfer book. The Company agrees that it will record any transfer of
Shares in its stock transfer book unless (i) the transfer does not materially
comply with all of the provisions of this Agreement or (ii) the transferee shall
not have agreed in writing to be bound by all of the provisions of this
Agreement applicable to the transferring Stockholders and become a party hereto.

      (f) Severability; Survivability. The provisions of this Agreement are
severable, so that the invalidity or unenforceability of any provision of this
Agreement shall not affect the validity or enforceability of any other term or
provision of this Agreement, which shall remain in full force and effect. In the
event that the term of this Agreement is restricted under applicable law, the
parties agree to, prior to termination of this Agreement, execute an agreement
on substantially similar terms.

      (g) Specific Performance. In addition to any and all other remedies that
may be available at law in the event of any breach of this Agreement, each
Stockholder shall be entitled to specific performance of the agreements and
obligations of the other parties hereunder and to such other injunctive or other
equitable relief as may be granted by a court of competent jurisdiction.

      (h) Subsequent Stockholders. It is understood and agreed that the terms
and conditions of this Agreement shall apply to whomsoever shall receive the
capital stock of the Company, including, by way of illustration and not of
limitation, bona fide purchasers for value. It shall be a condition precedent to
the issuance of the capital stock of the Company to any person by the Company
that said person shall agree to be bound by the terms and conditions of this
Agreement.

      (i) Alteration or Amendment. No change, modification or amendment of this
Agreement shall be valid unless the same is in writing and signed by the
Company, and the holders of a majority of each class of the Company's capital
stock or by all of the Stockholders if required by Section (a) or (b) above. No
waiver of any provision of this Agreement shall be valid unless in writing and
signed by the person against whom it is sought to be enforced. The failure of
any party at any time to insist upon strict performance of any condition,
promise, agreement or understanding set forth herein shall not be construed as a
waiver or relinquishment of the right to insist upon strict performance of the
same condition, promise, agreement or understanding at a future time. The
invalidity or unenforceability of any particular provision

                                      -10-
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hereof, this Agreement shall be construed in all respects as if such invalid or
unenforceable provisions were omitted.

      (j) Governing Law. This Agreement shall be governed by, and construed and
enforced in accordance with, the laws of the State of Florida. Each of the
Parties hereby irrevocably and unconditionally submits to the jurisdiction of
the courts of the State of Florida and the United States of America located in
the State of Florida (the "Florida Courts") for any litigation arising out of or
relating to this Agreement and the transactions contemplated hereby (and agree
not to commence any litigation relating thereto except in such courts), consent
to service of process in such Florida Courts, waive any objection to the laying
of venue of any such litigation in Alachua County, Florida, and agree not to
plead or claim in any Florida Court that such litigation brought therein has
been brought in any inconvenient forum.

      (k) Notices. Any and all notices or elections permitted or required to be
made under this Agreement shall be in writing, signed by the party giving such
notice or election and shall be delivered personally, by courier or sent by
registered or certified mail, return receipt requested, to the Company and the
Stockholders at their respective addresses below:

If to the Company to:

                  Regeneration Technologies, Inc.
                  One Innovation Drive
                  Alachua, Florida 32615
                  Attn: Richard R. Allen

                  with copy (which shall not constitute notice) to:

                  Piper & Marbury L.L.P.
                  1200 Nineteenth Street, N.W.
                  Washington, DC 20036
                  Attn: Theodore D. Segal, Esquire

If to the Class C Investors to:

                  Medtronic Asset Management, Inc.
                  7000 Central Avenue, N.E.
                  Minneapolis, MN 55402
                  Attn: Vice President & Chief Development Officer

                  with copy to:

                  Medtronic Asset Management, Inc.
                  7000 Central Avenue, N.E.
                  Minneapolis, MN 55402
                  Attn: General Counsel

                                      -11-
<PAGE>

                and

                Stephens-Regeneration LLC
                111 Center Street, Suite 2500
                Little Rock, AR 72201
                Attn: President

                with copy to:

                Stephens-Regeneration LLC
                111 Center Street, Suite 2500
                Little Rock, AR 72201
                Attn: Jackson Farrow, Esquire

      If to the Class A or Class B Investors, to the addresses set forth below
their respective names in Exhibit A and Exhibit B hereto.

      (l) Complete Agreement. This Agreement constitutes the full and complete
agreement of the parties hereto with respect to the subject matter hereof.

      (m) Pronouns. Whenever the content may require, any pronouns used in this
Agreement shall include the corresponding masculine, feminine or neuter forms,
and the singular form of nouns and pronouns shall include the plural, and vice
versa.

      (n) Counterparts. This Agreement may be executed in two counterparts, each
of which shall be deemed an original and both of which, when taken together,
shall constitute one and the same Agreement binding on all the parties hereto.

      (o) Captions. Captions of sections have been added only for convenience
and shall not be deemed to be a part of this Agreement.

                         [signatures on following page]

                                      -12-
<PAGE>

      IN WITNESS WHEREOF. this Agreement has been executed by the parties hereto
as of the and year first written above.

REGENERATION TECHNOLOGIES, INC.

By: /s/ JAMES M. GROOMS
   ---------------------------------------------
   Name: James M. Grooms
         President

CLASS C INVESTORS

MEDTRONIC ASSET MANAGEMENT, INC.

By: ____________________________________________
    Michael D. Ellwein
    Vice President and Chief Development Officer

________________________________________________

By:_____________________________________________

Name: __________________________________________

Its:____________________________________________

CLASS B INVESTORS

FREDERICK R. ADLER

________________________________________________
PHILIP R. CHAPMAN

________________________________________________
ADLER CHILDREN TRUST

By:_____________________________________________

Name: __________________________________________

Its:____________________________________________

                                      -13-
<PAGE>

      IN WITNESS WHEREOF, this Agreement has been executed by the parties hereto
as of the day and year first written above.

REGENERATION TECHNOLOGIES, INC.

By:
   ---------------------------------------------
   Name: James M. Grooms
         President

CLASS C INVESTORS

MEDTRONIC ASSET MANAGEMENT, INC.

By: /s/ Michael D. Ellwein
   ---------------------------------------------
    Michael D. Ellwein
    Vice President and Chief Development Officer

STEPHENS-REGENERATION LLC

________________________________________________

By:_____________________________________________

Name: __________________________________________

Its:____________________________________________

CLASS B INVESTORS

FREDERICK R. ADLER

________________________________________________
PHILIP R. CHAPMAN

________________________________________________
ADLER CHILDREN TRUST

By:_____________________________________________

Name: __________________________________________

Its:____________________________________________

                                      -14-<PAGE>

                                                                    EXHIBIT 10.8

                          CONTRACT OF PURCHASE AND SALE

      THIS CONTRACT OF PURCHASE AND SALE (this "Contract") is made and entered
into as of the "Effective Date" (as hereinafter defined) by and between ECHELON
INTERNATIONAL CORPORATION, a Florida corporation, its successors,
successors-in-title and assigns (hereinafter referred to as "Seller"), and
REGENERATION TECHNOLOGIES, INC., a Florida corporation, its successors and
assigns (hereinafter referred to as "Buyer").

                                   WITNESSETH:

      That for and in consideration of the mutual promises and covenants herein
contained and the mutual advantages accruing to Seller and Buyer, it is
covenanted and agreed by Seller and Buyer as follows:

      1. Property. Seller hereby agrees to sell to Buyer, and Buyer hereby
agrees to purchase from Seller, for the price and upon the terms and conditions
hereinafter set forth, that certain real property located within the Replat of
Progress Center, Plat Book P, Page 48, as recorded in Alachua County, Florida,
the general descriptions of which are more particularly described on Exhibit "A"
(consisting of approximately 6.19 acres, more or less) ("Land"), together with
the following:

      (a) All building and other improvements located on the Land ("Buildings");

      (b) All of Seller's right, title and interest in and to all appliance,
      fixtures, equipment, machinery, furniture, carpet, drapes and other
      personal property, if any, located on or about the Land and the Building,
      or used exclusively in the operation and maintenance thereof ("Tangible
      Personal Property");

      (c) All of Seller's right, title and interest in and to all of the service
      or maintenance contracts as set forth in Exhibit "B" attached hereto and
      made a part hereof ("Service Contracts");

As used in this Contract, the Land and the Buildings are collectively referred
to herein as the "Real Property" and the Real Property, Leases, Tangible
Personal Property, and Service Contracts. is collectively referred to herein as
the "Property."

      2. Deposit. Not later than 5:00 P.M. on January 31st, 2000, Buyer shall
deliver to Trenam, Kemker, Scharf, Barkin, Frye, O'Neill & Mullis, P.A., as
escrow agent (hereinafter called "Escrow Agent"), the sum of ONE HUNDRED
THOUSAND AND NO/100 DOLLARS ($100,000.00), which sum, together with all interest
earned thereon, is hereinafter collectively referred to as the "Deposit" and
shall be held in escrow by Escrow Agent in an interest-bearing account and in
accordance with the terms of this Contract. Escrow Agent shall notify Seller
upon its receipt of the Deposit. In the event that the Deposit has not been so
paid in the manner and by
<PAGE>

the time aforesaid (time being of the essence), this Contract, at the option of
Seller, shall immediately become null and void, and of no further force or
effect.

      3. Price and Terms. The purchase price ("Purchase Price") to be paid for
the Property shall be the sum of THREE MILLION SIX HUNDRED THOUSAND AND NO/100
DOLLARS ($3,600,000.00). The Purchase Price shall be payable to Seller at
Closing as follows:

            (A) The Deposit shall be paid to Seller and credited to Buyer
      against the Purchase Price;

            (B) At time of closing, Buyer shall pay to the Seller the remaining
      Purchase Price (or such greater or lesser amount as may be required by the
      credits, prorations and adjustments provided in this Contract) by wire
      transfer of immediately available funds.

      4. As Is.

            (a) EXCEPT AS EXPRESSLY PROVIDED HEREIN BUYER ACKNOWLEDGES AND
AGREES THAT THE PURCHASE AND SALE OF THE PROPERTY CONTEMPLATED BY THIS CONTRACT
IS AND WILL BE MADE ON AN "AS-IS" BASIS, WITH ALL FAULTS, PATENT AND LATENT, AND
WITHOUT RELIANCE UPON ANY REPRESENTATION OR WARRANTY OF ANY KIND OR NATURE,
EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTY OF
MERCHANTABILITY, HABITABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD, FAIR OR
ADEQUATE CONDITION OR REPAIR OR GOOD, WORKMANLIKE CONSTRUCTION, OR WARRANTIES OR
REPRESENTATIONS AS TO MATTERS OF TITLE (EXCEPT FOR WARRANTIES CONTAINED IN THE
SPECIAL WARRANTY DEED), ZONING, TAX CONSEQUENCES, PHYSICAL OR ENVIRONMENTAL
CONDITIONS, PROPERTY VALUE, OPERATING HISTORY, INCOME, EXPENSES, CHARGES, LIENS,
ENCUMBRANCES, RIGHTS OR CLAIMS, OR ANY OTHER MATTER OR THING RELATING TO OR
AFFECTING THE PROPERTY. IN ADDITION TO AND WITHOUT LIMITING THE GENERALITY OF
THE FOREGOING SENTENCE, EXCEPT AS OTHERWISE EXPRESSLY SET FORTH IN THIS
CONTRACT, SELLER MAKES NO REPRESENTATION OR WARRANTY OF ANY KIND WHATSOEVER AS
TO (I) THE NATURE OR CONDITION OF THE SOILS, GEOLOGY OR ANY GROUNDWATER ON THE
REAL PROPERTY; (II) THE DRAINAGE OF OR RELATING TO THE REAL PROPERTY; (III) THE
CONDITION OR REPAIR OF THE REAL PROPERTY INCLUDING ANY IMPROVEMENTS THEREON;
(IV) THE NATURE OR SUITABILITY OF ANY ZONING, LAND USE PLAN CLASSIFICATION, OR
EXISTING GOVERNMENTAL PERMITS, LICENSES OR APPROVALS; (V) THE FINANCIAL POSITION
OR NET OPERATING INCOME OF THE REAL PROPERTY, INCLUDING THE REVENUES AND
EXPENSES THEREOF; OR, (VI) THE PRESENCE OR ABSENCE OF ANY HAZARDOUS OR TOXIC
SUBSTANCES OR MATERIALS, WASTES, POLLUTANTS, CONTAMINANTS, OIL OR PETROLEUM
PRODUCTS ON, UNDER OR WITHIN THE REAL PROPERTY OR ON, UNDER OR WITHIN ANY LAND,

                                       2.
<PAGE>

IMPROVEMENTS, WATERCOURSE OR BODY OF WATER NEAR THE REAL PROPERTY. Buyer
REPRESENTS THAT IT IS A KNOWLEDGEABLE Buyer OF REAL ESTATE AND THAT IT IS
RELYING SOLELY ON ITS OWN EXPERTISE AND THAT OF Buyer'S CONSULTANTS, AND THAT
PRIOR TO CLOSING, BUYER WILL HAVE HAD A FULL AND FAIR OPPORTUNITY TO COMPLETE
ALL INSPECTIONS AND INVESTIGATIONS OF THE PROPERTY, INCLUDING BUT NOT LIMITED
TO, THE PHYSICAL AND ENVIRONMENTAL CONDITIONS THEREOF AS IT DEEMS NECESSARY, AND
SHALL RELY UPON SAME, AND UPON CLOSING, SHALL ASSUME THE RISK OF ALL ADVERSE
MATTERS, INCLUDING, BUT NOT LIMITED TO, ADVERSE PHYSICAL AND ENVIRONMENTAL
CONDITIONS.

            (b) By its acceptance of the Deed to the Real Property at the
Closing, Buyer shall be conclusively deemed to have acknowledged and agreed that
(i) any information or materials furnished to Buyer by Seller are provided as an
accommodation and Buyer acknowledges and agrees that Seller does not warrant,
represent or guarantee the accuracy or completeness of any documents,
information or item (other than copies of the Service Contracts) provided by
Seller or Seller's agent to Buyer, and that Seller will not be liable or
responsible for any errors, omissions or inaccuracies contained in any document,
information or item prepared by any party or entity, other than copies of the
Service Contracts and documents executed and delivered by Seller to Buyer at
Closing, and then only strictly in accordance with the terms of such closing
documents; and (ii) Buyer has relied solely on its independent investigations
and inspections and the documents to be delivered by Seller at closing in making
the decision to purchase the Property. The provisions of this Paragraph 4 shall
survive the Closing.

      5. New Lease. Buyer and Seller each agree, prior to Closing, to enter into
an amended and restated lease pertaining to space leased and to be leased to
Buyer at 13709 Progress Boulevard ("Progress Building"). The amended and
restated lease shall be in substitution of any and all existing lease agreements
between Buyer, as tenant, and Seller, as landlord, pertaining to Suites 130,
135, 1-7, 113 and 144 in the Progress Building, and shall provide the following
terms and conditions. Suites 130, 135, 1-7. 113 and 144, comprising of
approximately 7,492 rentable square feet, together with an additional 4,242
rentable square feet located on or within the areas known as Suites No. 102 and
118, (and, at tenant's option, up to an additional 4,260 rentable square feet of
space in the Progress Building, to the extent available) shall be leased to
tenant for a term that shall expire two (2) years from the date of the amended
and restated lease, at the rental rate of $15.00 per rentable square foot
(gross), all in its "as-is" condition, for office use and such other use
approved by landlord that will not require additional leasehold modifications
and building penetrations to the existing space. Tenant shall not have the right
to make any modifications or alterations to the premises. without the consent of
the landlord. Tenant shall also furnish the landlord with a security deposit
equal to one month's rent of the existing and additional space (or $14,667.50).
All other terms and conditions shall be substantially similar to the terms and
conditions of the lease governing Buyer's leased space at Innovation Drive.

                                       3.
<PAGE>

      6. Title Insurance. Within ten (10) days after the Effective Date, Seller
shall, at Seller's sole expense, furnish Buyer with a written commitment for the
issuance of an owner's policy of title insurance (ALTA Form B policy) on the
Real Property (the "Commitment") in the full amount of the Purchase Price,
issued by Lawyers Title Insurance Corporation ("Title Company"). If the
Commitment contains any exceptions that are not acceptable to Buyer in the
exercise of Buyer's sole discretion (other than the matters set forth in Exhibit
"C" attached hereto and incorporated by reference herein ("Existing
Exceptions")), then Buyer shall notify Seller in writing of such exceptions
within ten (10) days of its receipt of the Commitment (any such exceptions of
which Buyer gives Seller written notice within such ten (10) day period as
aforesaid being hereinafter defined as "Unauthorized Exceptions"); provided,
however, in no event (i) shall Seller have any obligation to undertake to cure,
remove or modify any of such Unauthorized Exceptions. The Existing Exceptions,
together with any other exceptions to which Buyer does not object within such
ten (10) day period as aforesaid, shall constitute "Permitted Exceptions"
hereunder, and Buyer shall be conclusively deemed to have waived its right to
object thereto. Seller shall have until the date of the Closing in which to
cause Title Company to remove any Unauthorized Exceptions.

      If Seller shall fail to cause any Unauthorized Exceptions to be removed
within the time period aforesaid, then: (a) Buyer may, at its option, elect to
terminate this Contract and to secure the return of the Deposit, whereupon this
Contract shall be null and void and, except as otherwise provided by Paragraph 5
hereof, Seller shall have no further obligations or liabilities hereunder; or
(b) Buyer may elect to close the purchase and sale of the Property in the same
manner as if no such Unauthorized Exceptions had arisen, without diminution in
the Purchase Price, in which case such Unauthorized Exceptions shall be deemed
to be a Permitted Exception. The immediately preceding sentence sets forth the
sole remedies of Buyer in the case of Seller's failure to cure any Unauthorized
Exceptions. Within a reasonable period of time following closing the title
insurance policy insuring Buyer's title to the Property. in the form prescribed
by the Commitment, shall be delivered to Buyer.

      7. Survey. Seller has previously delivered to Buyer a survey of the Real
Property and other adjacent lands dated as of September 9, 1999, prepared by
Eng, Denman & Associates, Inc., bearing Project Number 99-299 ("Existing
Survey"). Buyer, at Buyer's expense, shall have ten (10) days from and after the
Effective Date to have the Existing Survey modified, updated and recertified to
Buyer, Seller, and the Title Company ("Updated Survey"), which Updated Survey
shall show the boundaries and legal description of the land depicted on the
attached Exhibit "A", certify as to the actual number of acres contained within
the perimeters of the Land, and meet the minimum technical standards set forth
by Chapter 61G17-6, Florida Administrative Code, and the requirements of Section
627.7842, Florida Statutes ("Standards"), to enable the Title Company to delete
or modify the standard survey exception set forth in the Title Commitment. The
Surveyor shall (a) show all encroachments, ground improvements, easements
reflected on Exhibit "C" or otherwise shown on the Commitment or otherwise
visible to Surveyor, the flood zone designation of the Real Property and all
ground improvements affecting the Real Property necessary to comply with the
Standards. In the event that either the Survey shows any encroachments of and
improvements upon, from, or onto the Real Property, or an easement not disclosed
by the Permitted Exceptions, or shows any evidence of use which indicates that
an unrecorded easement may exist

                                       4.
<PAGE>

except as may be disclosed by the Permitted Exceptions or otherwise acceptable
to Buyer, in Buyer's sole discretion, Buyer shall deliver written notice to that
effect to Seller upon the later of (i) the expiration of the Inspection Period,
or (ii) five (5) days following delivery of the Updated Survey. Seller shall
have the same option to cure and curative period with respect to objections to
the Updated Survey as is described in Paragraph 6, above. If Buyer fails to
deliver written notice to Seller of any survey defects within such survey review
period, Buyer shall be deemed to have waived any Survey defects.

      8. Property Sold "As-Is"; Disclaimer of Warranties. Except as expressly
provided in this Contract, Seller makes no representations or warranties of any
kind whatsoever to Buyer. Buyer acknowledges and agrees as follows:

      (a) Reliance on Own Investigations. Buyer hereby acknowledges and agrees
      that has been given the opportunity to inspect the Property as Buyer sees
      fit, and Buyer shall rely solely on such investigations and not on any
      information furnished by Seller in making Buyer's decision to purchase or
      not purchase the Property. Buyer further acknowledges and agrees that any
      information concerning the Property furnished by Seller was obtained from
      a variety of sources and that Seller did not and is not required to make
      any independent investigation or verification of any such information with
      respect to accuracy, completeness or any other matter.

      (b) Assumption of Risk. From and after the Closing, Buyer hereby assumes
      all risks associated with ownership of the Property and any defects that
      may be located thereon or associated therewith of any the or nature
      whatsoever, and Buyer shall be solely responsible for and shall indemnify,
      protect, defend and hold Seller harmless from, all costs (including
      attorneys fees and court costs), expenses and all other claims incurred in
      or associated with such ownership and with the presence, removal or repair
      of any such defect. The foregoing indemnity shall not apply to any claims
      against Seller by third parties which accrue prior to the Closing.

      (c) General Release and Waiver. Buyer acknowledges and agrees that the
      unconditional "as is" nature of this transaction is a material inducement
      to Seller to enter into this Contract and to sell the Property to Buyer
      at the Purchase Price and upon the other terms and conditions set forth
      herein. As further consideration and material inducement to Seller, Buyer,
      on behalf of its principals, agents, successors and assigns, forever
      releases and discharges Seller, and Seller's officers, directors,
      shareholders, principals, agents, successors and assigns, from and against
      all claims, causes of action, losses, costs, damages, liabilities, and
      expenses of any kind which Buyer or any such other persons may now or at
      any time hereafter incur or realize in any manner from the Property, this
      Contract, and/or any matter arising herefrom or from the transactions
      contemplated hereby. Buyer has consulted with independent counsel of its
      choice regarding this Contract and the foregoing release and is knowingly
      and voluntarily entering into this Contract and agreeing to each provision
      hereof.

                                       5.
<PAGE>

The provisions of this Paragraph 8 shall survive the Closing.

      9. Closing Date. The Closing shall take place at the offices of Darryl A.
Tompkins, P.A. in Alachua County, Florida, on March 30, 2000, time being of the
essence.

      10. Closing Costs. Seller shall pay the premium for the owner's title
insurance policy and all search costs incidental to issuance of the Commitment,
and for documentary stamps on the deed. Buyer shall pay for the Updated Survey,
and any required updates thereto, for recording the deed, and any additional
title insurance endorsements requested by Buyer. Seller and Buyer shall each pay
their own attorneys' fees and legal assistants' fees in connection with
negotiating and closing this transaction.

      11. Seller's Closing Documents and Deliveries.

            (a) The Special Warranty Deed from Seller conveying the Property to
      Buyer, subject to the lien for real property taxes and assessments for the
      year of closing and subsequent years, the rights of parties in possession
      under unrecorded leases, and the Permitted Title Exceptions, together with
      the Florida Department of Revenue Form D-219;

            (b) An affidavit of an appropriate officer of Seller to permit the
      deletion of the construction lien exception and the "gap" exception from
      the Title Commitment and final title insurance policy, and to replace the
      parties in possession exception with the rights of tenants in possession
      under the Leases in effect as of Closing.

            (c) Closing statements;

            (d) A non-foreign affidavit as contemplated by 26 USCS Section 1445,
      as amended (the "FIRPTA Affidavit");

            (e) a Termination of the existing Lease between Seller and Buyer,
      together with the security deposits in Seller's possession, in form
      reasonably acceptable to Seller ("Lease Termination");

            (f) Originals of the Service Contracts, which Service Contracts
shall be all of the Service Contracts set forth in Exhibit "B" attached hereto,
together with letters to each service contractor from Seller advising each of
them of the sale of the Property and, the transfer of its contract;

            (g) A Bill of Sale conveying all of Seller's right, title and
interest in and to the Tangible Personal Property, in its "AS-IS, WHERE-IS"
condition, without representation or warranty of fitness or condition;

            (h) Possession of the Property.

                                       6.
<PAGE>

      12. Buyer's Closing Documents and Deliveries. At Closing, Buyer shall
deliver to Seller the following:

            (a) The balance of the Purchase Price as provided in Section 3 of
      this Contract, subject to prorations provided for in this Contract;

            (b) Closing statements;

            (c) A Lease Termination Agreement.

      13. Representations and Warranties of Buyer.

            In the event Buyer assigns its rights under this Contract to a
corporation or a limited liability company, Buyer shall then represent and
warrant to Seller, at the time of such assignment, that it is a duly organized
Florida limited liability company or corporation, validly existing and in good
standing, and is duly authorized and has all requisite power and authority to
execute this Contact and to consummate the transactions contemplated herein.

      14. Representations and Warranties of Seller. Seller hereby represents and
warrants to Buyer that:

            (a) Seller is a duly organized Florida corporation, validly existing
and in good standing, and is duly authorized and has all requisite power and
authority to execute this Contract and to consummate the transactions
contemplated herein. Seller further represents and warrants that the officer of
Seller who is executing this Contract and the documents to be delivered by
Seller at Closing has been duly authorized to do so by all necessary corporate
action of Seller. Seller's execution of this Contract and the performance by
Seller of its obligations hereunder do not and will not violate or breach any
document, instrument, agreement, order, rule, or regulation by which Seller or
the Property is bound or subject. If and to the extent, Seller transfers the
Property and assigns this Contract to a third party ("Assignee") prior to the
closing, Seller shall cause this representation and warranty to be restated, as
appropriate, for the status of the Assignee.

            (b) There are no suits, actions or proceedings pending against or
affecting Seller which may in any way adversely affect the Property or the
transaction provided herein; before or by any court or administrative agency or
officer, or, to Seller's knowledge, threatened, and, to Seller's knowledge,
Seller is not in default with respect to any judgment, order, writ, injunction,
rule or regulation of any court, or governmental agency to which it may be
subject, in any way that may adversely affect the Property or the transaction
provided herein.

            (c) Seller represents and warrants that it has complete and fall
authority to convey to Buyer the Property unencumbered by any right of first
offer or right of first refusal.

                                       7.
<PAGE>

            (d) There are no pending or, to Seller's knowledge, threatened
actions or proceedings to condemn all or any portion of the Property.

            (e) To Seller's knowledge, except as disclosed on the attached
Exhibit "D" and except as may be disclosed in that certain report prepared by
Matrix Compliance Services, Inc., dated as of August 19, 1999, no Hazardous
Materials (as hereinafter defined) have ever been dumped, discharged or
otherwise disposed of nor are any of the same located on the Property. The term
"Hazardous Materials" as used herein includes hazardous materials, hazardous
wastes, hazardous or toxic substances, polychlorinated biphenyls or related or
similar materials, or any other substance or material in such quantities as may
be defined as a hazardous or toxic substance by any federal, state or local
environmental law, ordinance, rule, or regulation including, without limitation,
the Comprehensive Environmental Response, Compensation and Liability Act of
1980, as amended (42 U.S.C. Sections 9601, et seq.), the Hazardous Materials
Transportation Act, as amended (49 U.S.C. Sections 1801, et seq.), the Resource
Conservation and Recovery Act, as amended (42 U.S.C. Sections 1251 et seq.), the
Clean Air Act (42 U.S.C. Sections 7401 et seq.), Chapter 376, Florida Statutes,
and in the regulations adopted and publications promulgated pursuant thereto.

            (f) The Property is part of a development of regional impact
development order, entitled "Progress Center Development of Regional Impact". To
Seller's knowledge, except as may be disclosed in that certain Memorandum dated
August 17, 1999, prepared by Nancy G. Linnan of Carlton Fields ("DRI Memo"), the
Property is in material compliance with all Progress Center DRI, as amended. To
Seller's knowledge, the Property is not vested against concurrency on certain
regional facilities, and that such concurrency is determined as such time an
owner of the Property or any portion thereof, seeks a building permit, as more
particularly set forth in the DRI Memo. The current zoning classification of the
Property will permit all of the uses granted to the Property under the Progress
Center DRI, as amended, including PUD zoning classification.

            (g) As of the Effective Date, there are no leases or service
contracts affecting the Real Property or any portion thereof which will survive
the Closing, other than the Service Contacts. There are no management contracts
that affect the Property that will survive the Closing.

As utilized in this Paragraph 11, the term "Seller's knowledge" shall mean the
actual present knowledge of Darryl A. LeClair, Sandy Burgess, and Mark Stroud,
without having conducted any independent investigation, inquiry or review.

It shall be a condition to Buyer's obligations hereunder that the foregoing
covenants and representations of Seller shall be true as of the date of Closing.
The foregoing representations of Seller shall survive the Closing, provided that
any action or claim based upon the failure of the representations or warranties
set forth hereinabove must be commenced within six months following the Closing.
In the event that Seller has made a representation herein which, at the time and
in the light of circumstances under which it is made, is false or misleading
with respect to any material fact,

                                       8.
<PAGE>

or omits to state any material fact necessary in order to make any statement
contained therein not false or misleading in any material respect, and Buyer has
knowledge of such misrepresentation prior to Closing, then Buyer, as Buyer's
sole remedy, may elect to terminate this Contract whereupon the Deposit shall be
returned to Buyer. In the event any of Seller's representations or warranties
shall prove to be false or incorrect and Buyer becomes aware of such false or
incorrect representations after Closing and within the time period provided in
this Section 14, Buyer shall have the right to collect from Seller its actual
damages on account thereof up to a maximum of Fifty Thousand and 00/100 Dollars
($50,000.00).

      15. Affirmative Covenants of Seller.

            (a) From and after the expiration of the Inspection Period until
Closing, Seller shall not execute or record any leases or modifications thereto,
or any mortgages or liens encumbering the Real Property, without the prior
written consent of Buyer, which consent shall not be unreasonably withheld or
delayed. Seller reserves the right, in its usual and customary course of
business, to amend, modify or terminate any of the Leases or to enter into new
Leases during the Inspection Period, and Seller agrees to deliver to Buyer
copies of any such instruments within two (2) business days following the full
execution of such instruments, but in all cases prior to the expiration of the
Inspection Period.

            (b) Seller agrees to continue to maintain the Property and all of
its improvements, parking areas and landscaping in the same fashion and
condition as in existence as of the Effective Date.

            (c) Seller agrees to immediately notify Buyer in the event Seller
receives any written notice of the commencement of any legal action or
proceeding that affects the Property or the transaction contemplated by this
Agreement, or in the event that Buyer receives written notification that the
Property is not in compliance with any applicable governmental rule or
regulation.

            (d) Seller shall maintain the Property in material compliance with
the Declaration.

      16. Affirmative Covenants of Buyer.

            (a) Buyer acknowledges and understands that the chiller system
located within the Building located on the Real Property also serves to furnish
the chilled water to building located in the commercial park and owned by
Seller. In addition, the pump and irrigation wells to furnish irrigation to
portions of landscaping to portions of the commercial park are also located on
the Real Property. Buyer also acknowledges that Seller has entered into a
contract to sell the remainder of the commercial park to Phil Hawley or its
assigns. Buyer acknowledges and agrees that it shall negotiate, in good faith,
with either Seller or Seller's successors-in-title, an agreement to permit and
maintain the continuing chilled water service to the adjacent other building(s)
in the park in

                                       9.
<PAGE>

exchange for a commercially reasonable fee, and to grant an easement to Seller
or its successor-in-title or assign for the maintenance, replacement, repair and
operation of the irrigation system so located on the Real Property.

      17. Conditions to Closing. The respective obligations of the parties to
consummate the Closing is subject to the satisfaction of each of the following
conditions prior to Closing:

      (a) Seller shall have obtained and delivered to Buyer a letter or
certificate from the City of Alachua or other governmental agency having
jurisdiction over the Property that the Property is in material compliance with
the Progress Center DRI. In addition, if so required by the terms of the
Progress Center DRI, Buyer shall be approved as an acceptable developer by such
agency having jurisdiction thereover.

      (b) Seller shall not have received any written notice from any
governmental agency of any pending or threatened condemnation or taking, or that
the Property is in violation of any applicable code, rule or ordinance.

      (c) Seller and Phil Hawley shall have entered into an amendment to the
Hawley Contract to release the Property subject to the terms of this Contract
from the terms and conditions of the Hawley Contract.

In the event that any of the above-stated conditions have not been or are not
fulfilled at or prior to Closing, then either party may terminate this
Agreement, whereupon the Deposit shall be refunded to Buyer and all rights and
obligations arising hereunder shall cease.

      18. Buyer's Default. If Buyer fails to consummate the purchase and sale of
the Property in accordance with the terms and conditions of this Contract, then
the Deposit shall be delivered by Escrow Agent to and retained by Seller as
agreed to and liquidated damages, and in full settlement of all claims by Seller
for such failure. This shall be Seller's sole remedy in the event of Buyer's
breach or default hereunder.

      19. Seller's Default. If Seller defaults in the performance of its
obligations under this Contract, then, at the option of Buyer, (a) Buyer may
terminate this Contract and, upon such termination, Buyer shall be entitled, on
demand, to the return of the Deposit paid by Buyer, or (b) Buyer shall have only
the right of specific performance without diminution in the Purchase Price.
These shall be the sole remedies of Buyer in the event of Seller's breach or
default hereunder.

      20. Damage or Destruction. Seller agrees to provide Buyer with prompt
written notice of any damage to or destruction of the Property of which Seller
has knowledge. In such event the parties' rights and obligations shall be as
follows:

            (a) If the "Repair Cost" is ten percent (10%) of the Purchase Price
      or less, then (i) at Closing, Buyer shall accept the Property subject to
      such damage or destruction, (ii) the

                                      10.
<PAGE>

      Purchase Price shall be reduced by the amount of the Repair Cost, and
      (iii) Seller shall retain the right to all proceeds of insurance. As used
      herein, the term "Repair Cost" means an estimate of the actual cost to
      repair the damage attributable to such damage or destruction and obtained
      by Seller within thirty (30) days following the event of damage or
      destruction from a reputable, licensed independent contractor selected by
      Seller and licensed to do business in the jurisdiction in which the
      Property is located.

            (b) If the Repair Cost exceeds ten percent (10%) of the Purchase
      Price, then either Buyer or Seller shall have the right to terminate this
      Contract, exercisable by giving written notice to the other party of such
      election within thirty (30) days after the determination of the Repair
      Cost, whereupon the Deposit shall be returned to Buyer with all interest
      accrued thereon. If neither party exercises such termination right, then
      (i) Buyer shall accept the Property at Closing subject to such damage or
      destruction, (ii) the Purchase Price shall be reduced by the amount of the
      Repair Cost, and (iii) Seller shall retain the right to all insurance
      proceeds.

      21. Attorneys' Fees. In the event either party is required to interpret or
enforce this Contract against the other, the prevailing party in any litigation
or other proceeding shall be entitled to recover, in addition to any other
remedy, its reasonable attorneys' fees, legal assistants' fees and costs: and
court costs, including those incurred on appeal and in bankruptcy or creditor's
reorganization proceedings.

      22. Prorations. The following items shall be paid. apportioned, and
prorated (based on the actual number of days in the month in which the Closing
Date occurs, assuming the Closing occurs at 12:01 a.m. on the Closing Date)
between Seller and Buyer:

            (a) Real property taxes for the then-current tax fiscal year shall
      be prorated based on the current year's tax, with full discount as
      permitted by law. If the current year's tax is not then available and the
      Closing occurs at a date when the current year's millage is not fixed and
      current year's assessment is available, taxes will be prorated based on
      such assessment and the prior year's millage. If the current year's
      assessment is not then available, taxes will be prorated on the prior
      year's tax, with full discount. Any tax proration based on an estimate, at
      request of either Buyer or Seller, may be readjusted after receipt of the
      tax bill. This provision shall survive the Closing.

            (b) All current installments for certified, confirmed, and ratified
      special assessment liens as of the Closing Date shall be paid by Seller,
      and the balance shall be assumed by Buyer. All liens for public
      improvements pending as of the Closing Date shall be assumed by Buyer.

            (c) Sums paid by Seller for fuel, water, and sewer service, and
      waste collection charges, and charges for electricity, telephone, and all
      other public utilities shall be prorated at Closing. Seller shall pay all
      utility bills in Seller's name that are due as of the Closing

                                      11.
<PAGE>

      Date. Buyer shall arrange for utility service in Buyer's name to commence
      on the Closing Date. Utility deposits previously paid b Seller shall be
      returned to Seller.

            (d) Rents and refundable security deposit (which will be assigned to
      and assumed by Buyer and credited to Buyer at Closing). This subparagraph
      of this Contract shall survive the Closing and the delivery and recording
      of the Deed.

            (e) All other usual and customary expenses, revenues, assessments,
      and other proratable items associated with the ownership, maintenance and
      operation of the Property shall be prorated as of the Closing Date.

      23. Brokers. Seller hereby (i) warrants and represents to Buyer that it
has had no dealings with any person or entity from which a valid claim for any
brokerage commission or similar fee could arise in connection with this Contract
or the transactions contemplated hereby; and (ii) agrees to defend. indemnify
and hold Buyer harmless from and against any claim by any third parties for
brokerage, commission, finders' or other fees relative to this Contract or the
sale of the Property and alleged to be due by authorization of, or as a result
of any actions taken by, Seller or its agents. together with any court costs,
attorneys' fees or other costs or expenses arising therefrom. Buyer hereby (i)
warrants and represents to Seller that it has had no dealings with any person or
entity from which a valid claim for any brokerage commission or similar fee
could arise in connection with this Contract or the transactions contemplated
hereby; and (ii) agrees to defend, indemnify and hold Seller harmless from and
against any claim by any third parties for brokerage, commission, finders' or
other fees relative to this Contract or the sale of the Property and alleged to
be due by authorization of, or as a result of any actions taken by, Buyer or its
agents, together with any court costs, attorneys' fees or other costs or
expenses arising therefrom. The representations, warranties and indemnification
obligations set forth in this Paragraph shall survive the Closing.

      24. Condemnation. If at any time prior to the delivery of the executed
Deed of conveyance to Buyer as herein provided, the Real Property or any portion
thereof is taken by eminent domain, or if any preliminary steps in any taking by
eminent domain of the Real Property any part thereof occurs prior to such
deliver or recording, Buyer may, at its option, within ten (10) days after
receipt of written notice of such fact from Seller, rescind this Contract, and
upon such rescission all monies deposited by Buyer under the terms hereof,
together with all interest earned thereon, shall be returned to Buyer upon
demand and thereupon all rights and liabilities arising hereunder shall
terminate. Seller shall notify Buyer in writing of any such taking by eminent
domain and all steps preliminary thereto as soon as the Seller has knowledge
thereof. In the event Buyer does not elect to rescind this Contract under such
circumstances, Buyer shall be entitled to all proceeds received or to be
received from any condemning authority, and Seller shall (i) pay to Buyer at
closing all such proceeds received by Seller, and (ii) assign to Buyer at
closing all such proceeds to be thereafter received from any condemning
authority by instrument of assignment in form reasonably acceptable to Buyer.

                                      12.
<PAGE>

      25. Entire Agreement. No agreements, representations or warranties, unless
expressly incorporated or set forth in this Contract, shall be binding upon any
of the parties. Neither the Closing hereunder nor any termination of this
Contract shall extinguish or otherwise impair any indemnification obligations
for which provision is made herein, regardless of whether or not the provision
imposing any such obligation expressly so states. All of the covenants,
warranties and representations set forth in this Contract shall be merged with
the Deed and shall not survive Closing (or any termination of this Contract),
unless and to the extent such covenant, warrant, and representation is expressly
provided to survive such Closing or termination of this Contract.

      26. Successors and Assigns; Singular and Plural Usages. The covenants
contained herein shall bind, and the benefits and advantages shall inure to, the
respective successors and assigns of the parties hereto. Seller reserves the
right to transfer the Property to a third party prior to closing, together with
an assignment to and assumption by such third party, of all of the benefit and
obligations of Seller under this Contract, whereupon Seller and Buyer each
acknowledge and agree that Buyer shall look to both Seller and to such third
party transferee for the performance and fulfillment of the obligations of the
seller under this Contract. Whenever used herein, the singular number shall
include the plural, the plural the singular, and the use of any gender shall
include all genders.

      27. Notification. Any notice, demand, consent, approval or other
communication to be given to or served upon any party hereto, in connection
herewith, must be in writing, and may be given by facsimile transmission,
certified mail return receipt requested or guaranteed overnight delivery
service. If a notice is delivered by United States Mail, it shall be deemed to
have been given and received two (2) days following the deposit of a certified
letter containing such notice, properly addressed, with postage prepaid, with
the United States Mail. If delivered by facsimile transmission or by guaranteed
overnight delivery service, it shall be deemed to have been given and received
the same day that the notice is faxed or delivered into the custody of the
overnight delivery service. If the notice is given otherwise than by certified
mail, facsimile transmission or guaranteed overnight delivery service, it shall
be deemed to have been given when delivered to and received by the party to whom
it is addressed. Notices shall be given to the parties hereto at the following
addresses:

      IF TO BUYER:      Regeneration Technologies, Inc.

      WITH A COPY TO:   Marvin W. Bingham, Jr., P.A.
                        14811 NW 140th St.
                        P.O. Box 1930
                        Alachua, FL 32616-1930
                        Attn: Marvin W. Bingham, Jr., Esquire
                        Telephone: (904) 462-5120
                        Telecopy: (904) 462-1996

                                 13.
<PAGE>

      IF TO SELLER:     Echelon International Corporation
                        450 Carillon Parkway Suite 200
                        St. Petersburg, Florida 33716
                        Attn: Mark Stroud
                        Telecopy: (727) 803-8202

      WITH A COPY TO:   Trenam, Kemker, Scharf, Barkin, Frye, O'Neill, & Mullis,
                        Professional Association
                        101 East Kennedy Boulevard
                        2700 Barnett Plaza
                        Tampa, Florida 33602
                        Attn: Mary H. Quinlan, Esquire
                        Telephone: (813) 223-7474
                        Telecopy: (813) 229-6553

      Failure or refusal of Seller or Buyer to accept delivery of or to claim a
notice that is required by the terms of this Contract to be received by the
party for which intended will not invalidate such notice, and such notice will
be effective and will be deemed received an the date of the refusal or failure
to claim the notice by the party for which intended. Any party hereto may change
its address for the service of notice hereunder by delivering written notice of
said change to the other parties hereunder. Any notice required or permitted
hereunder may be given by the attorney for a party to this Contract.

      28. Escrow Instructions. Escrow Agent shall incur no liability whatsoever
in connection with its good faith performance as Escrow Agent hereunder. The
parties hereby jointly and severally release and waive any claims they may have
against Escrow Agent which may result from its performance in good faith of such
function hereunder, specifically including, but not limited to, any delay in the
electronic wire transfer of funds. In its capacity as Escrow Agent hereunder,
Escrow Agent shall be liable only for loss or damage caused directly by its acts
of gross negligence or intentional misconduct while performing the duties
attendant thereto.

      In the event of any disagreement between the parties resulting in
conflicting instructions to, or adverse claims or demands upon, Escrow Agent
with respect to the release of any escrowed funds or documents, Escrow Agent may
refuse to comply with any such instruction, claim or demand so long as such
disagreement shall continue, and in so refusing Escrow Agent shall not be
obligated to release such funds or documents. Escrow Agent shall not be or
become liable in any way for its failure or refusal to comply with any such
conflicting instructions, or adverse claims or demands, and it shall be entitled
to continue to refrain from acting until such conflicting instructions, or
adverse claims or demands (i) have been adjusted by agreement and Escrow Agent
has been notified in writing thereof by the parties, or (ii) have finally been
determined in a court of competent jurisdiction. In the alternative, Escrow
Agent shall have the right to interplead the Deposit with the Clerk of the
Circuit Court of Alachua County. Florida, and upon notifying both Seller and
Buyer of

                                      14.
<PAGE>

such action, all liability of Escrow Agent hereunder shall terminate, except to
the extent of accounting for the Deposit.

      In the event of any suit between Seller and Buyer wherein Escrow Agent is
made a party by virtue of acting as escrow agent hereunder, or in the event of
any suit wherein Escrow Agent interpleads the Deposit, Escrow Agent shall be
entitled to recover reasonable fees (including but not necessarily limited to
fees for the services of attorneys and legal assistants) and costs incurred,
with such fees and costs to be charged and assessed as court costs in favor of
the prevailing party.

      Bu7yer acknowledges that Escrow Agent has acted as Seller's legal counsel
in connection with the negotiation and preparation of this Contract, and agrees
that Escrow Agent's capacity as escrow agent hereunder shall not disqualify
Escrow Agent from representing Seller in connection with any matters evidenced
or contemplated hereby or related hereto, including any litigation arising
hereunder.

      29. Time. Time is of the essence of this Contract and of each of its
provisions. Unless otherwise expressly provided in this Contract, any reference
herein to time periods of fewer than seven (7) days will in the computation
thereof exclude Saturdays, Sundays and all legal holidays. Notwithstanding any
provision of this Contract to the contrary, any time period which ends on a
Saturday, Sunday or legal holiday will automatically extend to 5:00 p.m. of the
next full day which is not a Saturday, Sunday or legal holiday. Wherever used in
this Contract, the term "Business Days" will mean Monday through Friday.
excluding legal holidays as expressly so defined in Florida Statutes Chapter 683
(1997).

      30. Effective Date. The "Effective Date" shall be the date of the later of
the execution date of this Contract by Seller and Buyer.

      31. Multiple Originals. This Contract may be executed in multiple
counterparts, each of which shall be deemed for all purposes to be an original,
but all of which shall constitute one and the same contract. At least one full
executed original of this Contract shall be delivered to each of Seller, Buyer
and Escrow Agent.

      32. Radon Gas. As required by applicable Florida statute, Seller hereby
discloses to Buyer the following:

            Radon is a naturally occurring radioactive gas that, when it has
            accumulated in a building in sufficient quantities, may present
            health risks to persons who are exposed to it over time. Levels of
            radon that exceed federal and state guidelines have been found in
            buildings in Florida. Additional information regarding radon and
            radon testing may be obtained from your county public health unit.

                                      15.
<PAGE>

      33. Controlling Law. This Contract shall be construed, governed,
interpreted and enforced in accordance with the laws of the State of Florida.

      IN WITNESS WHEREOF, the parties hereto have set their hands and seals
effective as of the later of the dates of execution hereof by Seller and Buyer.

Signed, sealed and delivered        SELLER:
in the presence of:
                                    ECHELON INTERNATIONAL
                                    CORPORATION, a Florida corporation

/s/ Sharon McBride                  By: /s/ Julio A. Maggi
--------------------------------       -----------------------------------------
                                        JULIO A MAGGI, Vice President

/s/ [ILLEGIBLE]                     Date: 31 JAN          , 2000
--------------------------------         -----------------
As to Seller

                                    BUYER

/s/ [ILLEGIBLE]                     By: /s/ [ILLEGIBLE]
--------------------------------       -----------------------------------------

/s/ [ILLEGIBLE]                     Date: 1/31/00         , 2000
--------------------------------         -----------------
As to Buyer

                                     JOINDER

      The undersigned Escrow Agent joins in the execution of this Contract to
agree to comply with the obligations of Escrow Agent hereunder.

                                    TRENAM KEMKER SCHARF BARKIN FRYE
                                    O'NEILL & MULLIS, P.A.

                                    By: Mary H. Quinlan
                                       -----------------------------------------

                                      16.
<PAGE>

                                   EXHIBIT "A"
                    [SKETCH OR LEGAL DESCRIPTION OF PROPERTY]
                            LEGAL DESCRIPTION - EB&TP

Parcel "C" of 'REPLAT OF PROGRESS CENTER' as per plat thereof recorded in Plat
Book P, pages 48 and 49 of the Public Records of Alachua County, Florida.
<PAGE>

                                    Exhibit B
                       Service and Maintenance Agreements
                      Echelon Business and Technology Park

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------------------------
                                                                            30 Day   Termination
Vendor                      Description             Amount                  Clause       Date
--------------------------------------------------------------------------------------------------------------------
<S>         <C>             <C>                     <C>                     <C>      <C>
W W Gay Mechanical          Preventive Maint on
                            Mechanical Equipment    $7,492.00 per year      Yes      Oct-00
            (Applies to both - can easily be split)
--------------------------------------------------------------------------------------------------------------------
York International          Preventive Maint on
                            Bldg 2 Chillers         $4,860.00 per year      No       Feb-00
            Building 2 Only
--------------------------------------------------------------------------------------------------------------------
Premier Water               Chemical for Cooling
                            Towers                  $17,184.00 per year     Yes      9/15/00
            Applies to both - can be split
--------------------------------------------------------------------------------------------------------------------
Boone Waste                 Solid Waste disposal    $565.00 per month       No       Feb-00

            Building 1 Only
--------------------------------------------------------------------------------------------------------------------
Quality Carpet/Janitorial   Cleaning Service        $3,620.00 per month     Yes      Dec-99 (has been re bid but no
                                                                                            contract has been signed
            Building 1 Only                                                                 for 2000)
--------------------------------------------------------------------------------------------------------------------
Earthgroomers               Landscaping             $6,400.00 per month     Yes      Dec-99 (has been re bid but no
                                                                                            contract has been signed
            All properties - can be split                                                   for 2000)
--------------------------------------------------------------------------------------------------------------------
Jacksonville Sound          Alarm Monitoring        $75.00 per month        Yes      Until notice is given

            Can be split
--------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                                   EXHIBIT "C"

                         [EXISTING PERMITTED EXCEPTIONS]

1.    General or special taxes and assessments for the year of closing and all
      subsequent years.

2.    "Progress Center Unit I Declaration of Covenants and Restrictions" dated
      March 19, 1985, and recorded in the Public Records of Alachua County,
      Florida, in Official Records Book 1588. Page 2207, as modified and amended
      by that certain First Amendment to Progress Center Unit 1 Declaration of
      Covenants and Restrictions dated February 12, 1990, and as further amended
      and modified pursuant to the terms of the "Second Amendment" recorded in
      O.R. Book 2161, Page 1701, all as recorded in the Public Records of
      Alachua County, Florida, in Official Records Book 1762, Page 1883, as
      joined in by Eye Research Laboratory, Inc., in that certain Joinder in
      Declaration and Restrictions dated March 18, 1985, and recorded in the
      Public Records of Alachua County, Florida, in Official Records Book 1588,
      Page 2205, (collectively, the "Declaration").

3.    Any easements, restrictions or other matters as shown on the Replat of
      Progress Center, Plat Book P, Page 49, as recorded in Alachua County,
      Florida.

4.    Easement from Context Development Company to City of Alachua, recorded in
      O.R. Book 1241, Page 113;

5.    Terms and conditions of Agreement executed by and between Apalachee
      Development and the State of Florida D.C.A, recorded in O.R. Book 1605,
      Page 1374; amendment thereto recorded in O.R. Book 1617, Page 613;

6.    Terms and conditions set forth in Notice of Development Order approving
      the Development of Regional Impact known as Progress Center recorded in
      O.R. Book 1692, Page 1378, as amended ("Progress Center DRI"):

7.    Easement from Talquin Development Company, successor of Apalachee
      Development Company, to City of Alachua, Florida, recorded in O.R. Book
      1668, Page 982;

8.    Distribution Right of Way easement from Talquin Development Company to
      Clay Electric Cooperative, Inc. recorded in O.R. Book 1751, Page 1007;

9.    Easement from Talquin Development Company to City of Alachua, recorded in
      O.R. Book 1822, Page 727;

10.   Terms and conditions set forth in Drainage Easement Agreement recorded in
      O.R. Book 1830, Page 345;

11.   Easement from Talquin Development Company to City of Gainesville recorded
      in O.R. Book 1870 Page 2987;
<PAGE>

12.   Easement from Talquin Development Company to the Board of Trustees of the
      Internal Improvement Trust Fund of the State of Florida recorded in O.R.
      Book 1993, Page 358;

13.   Public Utilities and Drainage Easement shown on the Progress Center Plat
      recorded in Plat Book M, Page 82;

14.   Twenty (20) foot drainage easement set forth in Warranty Deed recorded in
      O.R. Book 1959;

15.   Rights of tenants under unrecorded Leases.

All recording in the public records of Alachua County, Florida
<PAGE>

                                   EXHIBIT "D"

Seller advises Buyer that on or around 1990, some anti-freeze material was
released from a chiller line. Seller voluntarily caused the removal of all of
the contaminated soils to the county landfill. Seller advised the local office
of environmental protection for Alachua County of the incident. A representative
of the agency visited the site of the spill and verbally advised Seller of Its
acceptance of the condition and clean-up.
<PAGE>

ENG
  DENMAN &
    ASSOCIATES, INC.
--------------------------------------------------------------------------------
                        ENGINEERS o SURVEYORS o PLANNERS

February 17, 2000

Legal Description
For: Regeneration Technologies, Inc.

A portion of Government Lots 1 and 2 in Section 24, Township 8 South, Range 18
East, and being a portion of Replat of Progress Center as per plat thereof
recorded in Plat Book "P", pages 48 and 49 of the Public Records of Alachua
County, Florida; all lying and being in the City of Alachua, Alachua County,
Florida and being more particularly described as follows:

Parcel C of Replat of Progress Center as per plat thereof recorded in Plat Book
P, pages 48 and 49 of the Public Records of Alachua County, Florida.

Containing 6.20 acres (269,847 square feet), more or less.

             2404 NW 43RD STREET o GAINESVILLE, FLORIDA 32606-6602 o
                    TEL. (352) 373-3541 o FAX (352) 373-7249
<PAGE>

ENG
  DENMAN &
    ASSOCIATES, INC.
--------------------------------------------------------------------------------
                        ENGINEERS o SURVEYORS o PLANNERS

February 17, 2000

Legal Description
For: Regeneration Technologies, Inc.

A portion of Government Lots 1 and 2 in Section 24, Township 8 South, Range 18
East, and being a portion of Replat of Progress Center as per plat thereof
recorded in Plat Book "P", pages 48 and 49 of the Public Records of Alachua
County, Florida; all lying and being in the City of Alachua, Alachua County,
Florida and being more particularly described as follows:

PARCEL 1:

Commence at the northwest corner of Parcel C of Replat of Progress Center as per
Plat thereof recorded in Plat Book "P", pages 48 and 49 of the Public Records of
Alachua County, Florida and run thence North 87(degree)15'29" East along the
northerly boundary of said Parcel C, a distance of 135.00 feet; thence South
49(degree)23'12" East along said northerly boundary, a distance of 100.76 feet
to the POINT OF BEGINNING (#1); thence continue South 49(degree)23'12" East
along said northerly boundary, a distance of 279.24 feet; thence North
70(degree)36'48" East along said northerly boundary, a distance of 23.73 feet to
a point on the northwesterly right-of-way line of Innovation Drive (100' R/W),
said point being hereinafter referred to as Point A and being on the arc of a
curve concave northwesterly and having a radius of 200.00 feet; thence
northeasterly along the arc of said curve and along said northwesterly
right-of-way line through a central angle of 27(degree)56'18", an arc distance
of 97.52 feet to the end of said curve, said arc being subtended by a chord
having a bearing and distance of North 56(degree)38'39" East, 96.56 feet; thence
North 42(degree)40'31" East, along said northwesterly right-of-way line, a
distance of 377.75 feet to a point at the intersection of said northwesterly
right-of-way line with the southerly right-of-way line of Research Circle (80'
R/W), said point being on the arc of a curve concave southwesterly and having a
radius of 560.00 feet; thence northwesterly along the arc of said curve, and
along said southerly right-of-way line, through a central angle of
32(degree)05'54", an arc distance of 313.73 feet to the end of said curve, said
arc being subtended by a chord having a bearing and distance of North
68(degree)29'48" West, 309.64 feet; thence North 84(degree)32'45" West along
said southerly right-of-way line, a distance of 256.00 feet to a point at the
northeasterly corner of that certain parcel of land as described in Official
Records Book 2264, pages 2522 et seq. of said Public Records; thence South
05(degree)27'15" West along the easterly boundary of said parcel (OR 2264, pgs
2522 et seq.), a distance of 296.09 feet to the POINT OF BEGINNING.

TOGETHER WITH:

Commence at Point A as described above and run thence South 19(degree)23'12"
East, along the easterly boundary of said Parcel C of Replat of Progress Center,
and along the southwesterly end of the

             2404 NW 43RD STREET o GAINESVILLE, FLORIDA 32606-6602 o
                    TEL. (352) 373-3541 o FAX (352) 373-7249
<PAGE>

right-of-way of Innovation Drive (100' R/W), a distance of 100.00 feet to a
point on the southeasterly right-of-way line of said Innovation Drive and the
POINT OF BEGINNING (#2); thence South 70(degree)36'48" West along the easterly
boundary of said Parcel C, a distance of 23.73 feet; thence South
10(degree)36'48" West along said easterly boundary, a distance of 478.17 feet to
a point on the southerly boundary of said Parcel C; thence North
79(degree)23'12" West along said southerly boundary, a distance of 64.00 feet;
thence North 13(degree)16'55" West along said southerly boundary, a distance of
86.41 feet; thence North 79(degree)23'12" West, a distance of 290.65 feet to the
southwesterly corner of said Parcel C; thence South 02(degree)55'52" West, a
distance of 624.31 feet to a point on the northerly right-of-way line of
Research Circle (80' R/W), as per deed recorded in Official Records Book 2213,
pages 2412 et seq. of said public records; thence South 87(degree)04'08" East
along said northerly right-of-way line, a distance of 155.06 feet to the
beginning of a curve concave northwesterly and having a radius of 810.00 feet;
thence northeasterly along the arc of said curve and along the northerly and
westerly right-of-way line of said Research Circle through a central angle of
94(degree)23'11", an arc distance of 1334.36 feet to the end of said curve, said
arc being subtended by a chord having a bearing and distance of North
45(degree)44'17" East, a distance of 1188.51 feet; thence North 01(degree)27'18"
West along said westerly right-of-way line, a distance of 217.62 feet to the
beginning of a curve concave southwesterly and having a radius of 410.00 feet;
thence northwesterly along the arc of said curve and along said westerly
right-of-way line through a central angle of 41(degree)54'28", an arc distance
of 299.89 feet to a point at the intersection of said westerly right-of-way line
with the southeasterly right-of-way line of said Innovation Drive, said arc
being subtended by a chord having a bearing and distance of North
22(degree)24'33" West, a distance of 293.25 feet; thence South 42(degree)40'31"
West along said southeasterly right-of-way line, a distance of 379.00 feet to
the beginning of a curve concave northwesterly and having a radius of 300.00
feet; thence southwesterly along the arc of said curve and along said
southeasterly right-of-way line through a central angle of 27(degree)56'18", an
arc distance of 146.28 feet to the POINT OF BEGINNING, said arc being subtended
by a chord having a bearing and distance of South 56(degree)38'39" West, a
distance of 144.84 feet.

Containing in aggregate 20.82 acres (907,292 square feet), more or less.
<PAGE>

                         FIRST AMENDMENT TO CONTRACT OF
                                PURCHASE AND SALE

      THIS FIRST AMENDMENT is entered into as of this ____ day of ________,
2000, by and between Echelon International Corporation, a Florida corporation,
its successors, successors-in-title, and/or assigns, as "Seller", and
Regeneration Technologies, Inc., a Florida corporation, its successors and/or
assigns, as "Buyer."

      WHEREAS, the parties have entered into that certain Contract of Purchase
and Sale dated the 31st day of January, 2000, for the property located in
Alachua County, Florida, more particularly described therein; and

      WHEREAS, Buyer and Seller have requested an amendment to the Contract of
Purchase and Sale.

      NOW, THEREFORE, the Buyer and Seller agree as follows:

      1.    Exhibit "A", the Legal Description, is hereby amended to increase by
            20.82 acres of land as described on the exhibit attached hereto to
            and made a part hereof.

      2.    Paragraph III, Section 3, is hereby amended to increase the purchase
            price by $624,600.00 ($30,000.00 x 20.82 acres).

      All provisions of the original Agreement not amended herein shall remain
unchanged and in full force and effect. This Amendment may be executed in
counterparts, via facsimile, and signed counterparts, when combined, shall
constitute one and the same instrument.

      IN WITNESS WHEREOF, the parties have set their hands and seals this
________ day of _____________, 2000.

In the presence of:              "BUYER"

                                 REGENERATION TECHNOLOGIES, INC.,
                                 a Florida corporation

/s/ Robert W. Clark              By: /s/ Richard R. Allen
-----------------------------       -------------------------------------
                                 Printed Name: Richard R. Allen
                                              ---------------------------
                                 Its: CFO/Sec/Treas
                                     ------------------------------------
/s/ [ILLEGIBLE]
-----------------------------
As to Buyer

                                 "SELLER"

                                 ECHELON INTERNATIONAL
                                 CORPORATION, a Florida Corporation

                                 By:
-----------------------------       -------------------------------------
                                 Printed Name:
                                              ---------------------------
                                 Its:
                                     ------------------------------------

-----------------------------
As to Seller
<PAGE>

ENG
  DENMAN &
    ASSOCIATES, INC.
--------------------------------------------------------------------------------
                        ENGINEERS o SURVEYORS o PLANNERS

February 17, 2000

Legal Description
For: Regeneration Technologies, Inc.

A portion of Government Lots 1 and 2 in Section 24, Township 8 South, Range 18
East, and being a portion of Replat of Progress Center as per plat thereof
recorded in Plat Book "P". pages 48 and 49 of the Public Records of Alachua
County, Florida; all lying and being in the City of Alachua, Alachua County,
Florida and being more particularly described as follows:

PARCEL 1:

Commence at the northwest corner of Parcel C of Replat of Progress Center as per
Plat thereof recorded in Plat Book "P", pages 48 and 49 of the Public Records of
Alachua County, Florida and run thence North 87(degree)15'29" East along the
northerly boundary of said Parcel C, a distance of 135.00 feet; thence South
49(degree)23'12" East along said northerly boundary, a distance of 100.76 feet
to the POINT OF BEGINNING (#1); thence continue South 49(degree)23'12" East
along said northerly boundary, a distance of 279.24 feet; thence North
70(degree)36'48" East along said northerly boundary, a distance of 23.73 feet to
a point on the northwesterly right-of-way line of Innovation Drive (100' R/W),
said point being hereinafter referred to as Point A and being on the arc of a
curve concave northwesterly and having a radius of 200.00 feet; thence
northeasterly along the arc of said curve and along said northwesterly
right-of-way line through a central angle of 27(degree)56'18", an arc distance
of 97.52 feet to the end of said curve, said arc being subtended by a chord
having a bearing and distance of North 56(degree)38'39" East, 96.56 feet; thence
North 42(degree)40'31" East, along said northwesterly right-of-way line, a
distance of 377.75 feet to a point at the intersection of said northwesterly
right-of-way line with the southerly right-of-way line of Research Circle (80'
R/W), said point being on the arc of a curve concave southwesterly and having a
radius of 560.00 feet; thence northwesterly along the arc of said curve, and
along said southerly right-of-way line, through a central angle of
32(degree)05'54", an arc distance of 313.73 feet to the end of said curve, said
arc being subtended by a chord having a bearing and distance of North
68(degree)29'48" West, 309.64 feet; thence North 84(degree)32'45" West along
said southerly right-of-way line, a distance of 256.00 feet to a point at the
northeasterly corner of that certain parcel of land as described in Official
Records Book 2264, pages 2522 et seq. of said Public Records; thence South
05(degree)27'15" West along the easterly boundary of said parcel (OR 2264, pgs
2522 et seq.), a distance of 296.09 feet to the POINT OF BEGINNING.

TOGETHER WITH:

Commence at Point A as described above and run thence South 19(degree)23'12"
East, along the easterly boundary of said Parcel C of Replat of Progress Center,
and along the southwesterly end of the

             2404 NW 43RD STREET o GAINESVILLE, FLORIDA 32606-6602 o
                    TEL. (352) 373-3541 o FAX (352) 373-7249
<PAGE>

right-of-way of Innovation Drive (100' R/W), a distance of 100.00 feet to a
point on the southeasterly right-of-way line of said Innovation Drive and the
POINT OF BEGINNING (#2); thence South 70(degree)36'48" West along the easterly
boundary of said Parcel C, a distance of 23.73 feet; thence South
10(degree)36'48" West along said easterly boundary, a distance of 478.17 feet to
a point on the southerly boundary of said Parcel C; thence North
79(degree)23'12" West along said southerly boundary, a distance of 64.00 feet;
thence North 13(degree)16'55" West along said southerly boundary, a distance of
86.41 feet; thence North 79(degree)23'12" West, a distance of 290.65 feet to the
southwesterly corner of said Parcel C; thence South 02(degree)55'52" West, a
distance of 624.31 feet to a point on the northerly right-of-way line of
Research Circle (80' R/W), as per deed recorded in Official Records Book 2213,
pages 2412 et seq. of said public records; thence South 87(degree)04'08" East
along said northerly right-of-way line, a distance of 155.06 feet to the
beginning of a curve concave northwesterly and having a radius of 810.00 feet;
thence northeasterly along the arc of said curve and along the northerly and
westerly right-of-way line of said Research Circle through a central angle of
94(degree)23'11", an arc distance of 1334.36 feet to the end of said curve, said
arc being subtended by a chord having a bearing and distance of North
45(degree)44'17" East, a distance of 1188.51 feet; thence North 01(degree)27'18"
West along said westerly right-of-way line, a distance of 217.62 feet to the
beginning of a curve concave southwesterly and having a radius of 410.00 feet;
thence northwesterly along the arc of said curve and along said westerly
right-of-way line through a central angle of 41(degree)54'28", an arc distance
of 299.89 feet to a point at the intersection of said westerly right-of-way line
with the southeasterly right-of-way line of said Innovation Drive, said arc
being subtended by a chord having a bearing and distance of North
22(degree)24'33" West, a distance of 293.25 feet; thence South 42(degree)40'31"
West along said southeasterly right-of-way line, a distance of 379.00 feet to
the beginning of a curve concave northwesterly and having a radius of 300.00
feet; thence southwesterly along the arc of said curve and along said
southeasterly right-of-way line through a central angle of 27(degree)56'18", an
arc distance of 146.28 feet to the POINT OF BEGINNING, said arc being subtended
by a chord having a bearing and distance of South 56(degree)38'39" West, a
distance of 144.84 feet.

Containing in aggregate 20.82 acres (907,292 square feet), more or less.

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