<PAGE>

                                                                   Exhibit 10.33

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                          MASSACHUSETTS INSTITUTE OF TECHNOLOGY

                                   AMENDED AND RESTATED

                                    LICENSE AGREEMENT

                                       (EXCLUSIVE)

                                                              Date: July 1, 1996
<PAGE>

                                    TABLE OF CONTENTS

PREAMBLE                                                                  PAGE

ARTICLE 1 - DEFINITIONS......................................................2

ARTICLE 2 - GRANT............................................................5

ARTICLE 3 - DUE DILIGENCE....................................................8

ARTICLE 4 - ROYALTIES.......................................................10

ARTICLE 5 - REPORTS AND RECORDS.............................................14

ARTICLE 6 - PATENT PROSECUTION..............................................15

ARTICLE 7 - INFRINGEMENT....................................................17

ARTICLE 8 - PRODUCT LIABILITY AND REPRESENTATION............................19

ARTICLE 9 - EXPORT CONTROLS.................................................22

ARTICLE 10 - NON-USE OF NAMES...............................................22

ARTICLE 11 - ASSIGNMENT.....................................................23

ARTICLE 12 - DISPUTE RESOLUTION.............................................23

ARTICLE 13 - TERMINATION....................................................24

ARTICLE 14 - PAYMENTS, NOTICES AND OTHER COMMUNICATIONS.....................25

ARTICLE 15 - MISCELLANEOUS PROVISIONS.......................................26

APPENDIX A
APPENDIX B
<PAGE>

      This Amended and Restated License Agreement (Exclusive) is made and
entered into this 1st day of July, 1996, by and between MASSACHUSETTS INSTITUTE
OF TECHNOLOGY, a corporation duty organized and existing under the laws of the
Commonwealth of Massachusetts and having its principal office at 77
Massachusetts Avenue, Cambridge, Massachusetts 02139, U.S.A. (hereinafter
referred to as "M.I.T."), and REPROGENESIS, INC., a corporation duly organized
and existing under the laws of the State of Texas and having its principal
office at 10 Sylvan Drive, Suite 27, St. Simons Island, Georgia 31522
(hereinafter referred to as "LICENSEE"), such LICENSEE the successor in interest
to Reprogenesis, L.P.

                                   WITNESSETH

      WHEREAS, pursuant to the terms and conditions of that certain License
Agreement (the "License Agreement"), dated December 23, 1993 (the "Effective
Date"), by and between M.I.T. and Tissue Technologies, L.P., M.I.T. on its own
behalf and on behalf of Children's Hospital of Boston ("Children's Hospital')
granted exclusive licenses under certain PATENT RIGHTS (as later defined herein)
in the FIELD OF USE (as later defined herein) to Tissue Technologies, L.P.
(whose name was subsequently changed to Reprogenesis, L.P.) and the granted
rights are subject only to a royalty free, non-exclusive license heretofore
granted to the United States Government; and

      WHEREAS, subsequent to the Effective Date and prior to the date hereof,
M.I.T. and Reprogenesis, L.P. entered into seven separate amendments to the
License Agreement; and

      WHEREAS, effective July 1, 1996, Reprogenesis, L.P. was merged with and
into LICENSEE, with LICENSEE succeeding to all of the rights and obligations of
Reprogenesis, L.P., including those under the License Agreement; and

      WHEREAS, M.I.T. and LICENSEE desire to enter into this Amended and
Restated License Agreement to (1) restate the License Agreement to give effect
to the seven separate


                                      -1-
<PAGE>

amendments heretofore executed; (2) evidence the consent of M.I.T. to the change
in legal status of Reprogenesis, L.P. and the succession of LICENSEE to the
rights and obligations of Reprogenesis, L.P. under the License Agreement as
permitted in Article II of the License Agreement; (3) reflect the payment of the
License Issue Fee and the issuance to M.I.T. of the Common Stock of LICENSEE in
compliance with the provisions of Article IV of the License Agreement; (4)
delete the provisions of the License Agreement providing for the obligation of
LICENSEE to raise "Investment Capital" pursuant to an agreed schedule and
providing "antidilution" rights to M.I.T. until such time as such Investment
Capital exceeded $5.0 million, M.I.T. having agreed that such schedule has been
met and Investment Capital in excess of $5.0 million has been raised; (5) amend
the provisions of the License Agreement with respect to the "pre-emptive rights"
of M.I.T. to clarify the extent of such rights, establish procedures for the
exercise thereof and provide that such rights do not extend to issuances of
securities by LICENSEE pursuant to employee benefit plans and in certain other
limited circumstances; and (6) to make certain other conforming changes, all as
agreed to by M.I.T. and LICENSEE;

      NOW, THEREFORE, in consideration of the premises and the mutual covenants
contained herein, the parties hereto amend and restate the License Agreement and
agree as follows:

                            ARTICLE 1 - DEFINITIONS

      For the purposes of this Agreement, the following words and phrases shall
have the following meanings:

      1.1. "LICENSEE" shall include Carolina Tissue Development Partners, a
Texas general partnership, and any other related company of Reprogenesis, Inc.,
the voting stock of which is directly or indirectly at least Fifty Percent (50%)
owned or controlled by Reprogenesis, Inc., an organization which directly or
indirectly controls more than Fifty Percent (50%) of the


                                      -2-
<PAGE>

voting stock of Reprogenesis, Inc., and an organization, the majority ownership
of which is directly or indirectly common to the ownership of Reprogenesis, Inc.

      1.2 "PATENT RIGHTS" shall mean all of the following intellectual property
owned or controlled by M.I.T. and/or Children's Hospital:

          (a) the United States and foreign patents and/or patent applications
              listed in Appendix A and divisionals and continuations of these
              applications;

          (b) United States and foreign patents issued from the applications
              listed in Appendix A and from divisionals and continuations of
              these applications;

          (c) claims of United States and foreign continuation-in-part
              applications, and of the resulting patents, which are directed to
              subject matter described in the United States and foreign
              applications listed in Appendix A;

          (d) claims of all foreign patent applications, and of the resulting
              patents, which are directed to subject matter described in the
              United States patents and/or patent applications described in (a),
              (b) or (c) above; and

          (e) any reissues, reexaminations or extensions of United States and
              foreign patents described in (a), (b) or (c) above.

      1.3 A "LICENSED PRODUCT" shall mean any product or part thereof which:

          (a) is covered in whole or in part by a claim that has not expired or
              been held invalid by a court of competent jurisdiction or by a
              pending claim after January 1, 1997, contained in the PATENT
              RIGHTS in the country in which any such product or part thereof is
              made, used or sold; or

          (b) is manufactured by using a process or is employed to practice a
              process which is covered in whole or in part by a claim that has
              not expired or been held invalid by a court of competent
              jurisdiction or by a pending claim after January 1, 1997,
              contained in the PATENT RIGHTS in the country in which any
              LICENSED PROCESS is used or in which such product or part thereof
              is used or sold.

      1.4 "A LICENSED PROCESS" shall mean any process which is covered in whole
or in part by a claim that has not expired or been held invalid by a court of
competent jurisdiction or by a pending claim after January 1, 1997, contained in
the PATENT RIGHTS.


                                      -3-
<PAGE>

      1.5 A "LICENSED SERVICE" shall mean any fee-bearing service performed by
LICENSEE or any sublicensee which uses a LICENSED PRODUCT or practices a
LICENSED PROCESS.

      1.6 "COMBINATION PRODUCTS(S)" or "SERVICES(S)" shall mean a product or
service that includes a LICENSED PRODUCT or LICENSED SERVICE sold in combination
with other component(s) whose manufacture, use or sale by an unlicensed party
would not constitute an infringement of the PATENT RIGHTS.

      1.7 "NET SALES" shall mean LICENSEE'S (and its sublicensees') billings to
a third party for LICENSED PRODUCTS, LICENSED PROCESSES and LICENSED SERVICES
produced hereunder less the sum of the following:

          (a) discounts allowed in amounts customary in the trade;

          (b) sales, tariff duties and/or use taxes directly imposed and with
              reference to particular sales;

          (c) outbound transportation prepaid or allowed;

          (d) insurance;

          (e) amounts allowed or credited on returns; and

          (f) bad debts.

Sales between LICENSEE and any of its affiliates or any of its sublicensees, or
between any of said affiliates or sublicensees, shall not be included in such
computation. If the LICENSED PRODUCT or SERVICE is sold together with one or
more other components in order to provide a COMBINATION PRODUCT or SERVICE, the
NET SALES, as defined above, shall be multiplied by a fraction, the numerator of
which shall be the cost of the LICENSED PRODUCT or SERVICE contained in such
COMBINATION PRODUCT or SERVICE, and the denominator of which shall be the total
cost of the COMBINATION PRODUCT or SERVICE, the cost in


                                      -4-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

each case to be determined in accordance with LICENSEE'S regular accounting
practice, consistently applied. No deductions shall be made for commissions paid
to individuals, whether they be with independent sales agencies or regularly
employed by LICENSEE and on its payroll, or for cost of collections. LICENSED
PRODUCTS shall be considered "sold" upon the earlier of receipt of payment or
six months after billed out or invoiced.

      1.8 "FIELD OF USE" shall mean all applications in the [**] and [**]
fields, including repair, growth, replacement, augmentation and regeneration of
[**], [**] or [**] of the [**] and [**] or the creation, restoration,
augmentation, limitation or elimination of [**] of said [**], including
integrally associated [**] ([**] or [**]) such as [**], [**], [**], [**], and
[**] and [**] components, where the [**] includes the [**].

      1.9 "[**] PATENT RIGHTS" shall mean PATENT RIGHTS related to M.I.T. Case
No. [**], "[**]" by Keith Paige, Linda Cima, Charles Vacanti and Anthony Atala
as listed in Appendix A, including all divisionals, continuations and
continuation-in-part applications directed to the subject matter claimed in the
parent applications.

                               ARTICLE 2 - GRANT

      2.1 M.I.T. hereby grants to LICENSEE the exclusive worldwide right and
license under the PATENT RIGHTS to make, have made, use, lease and sell the
LICENSED PRODUCTS and LICENSED SERVICES and to practice the LICENSED PROCESSES
in the FIELD OF USE to the end of the term for which the PATENT RIGHTS are
granted.

      2.2 M.I.T. also grants to LICENSEE a first option to add to the PATENT
RIGHTS of this Agreement any patents, patent applications and inventions owned
by M.I.T and/or Children's Hospital (including those jointly owned with third
parties) which are conceived or


                                      -5-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

reduced to practice either solely or jointly with others by researchers
associated with the laboratories of (a) Professor Robert S. Langer at M.I.T. or
Children's Hospital, (b) Dr. Joseph P. Vacanti at Children's Hospital and/or (c)
Dr. Anthony Atala at Children's Hospital within four (4) years of the Effective
Date which are dominated by any filed or issued claims of PATENT RIGHTS. This
option shall be restricted to the FIELDS OF USE. M.I.T. shall have the duty to
notify LICENSEE within three (3) months of receipt of a written disclosure of
any such invention. This option shall expire six (6) months from the date at
which M.I.T. notifies LICENSEE of the invention. LICENSEE shall pay to M.I.T. a
License Issue Fee to be negotiated, but not to exceed [**] Dollars ($[**] for
each invention under this Paragraph 2.2 on which a patent application is filed,
excluding additional payments for continuations, divisionals and
continuations-in-part applications which shall be directed to subject matter
specifically described in the original patent application as of the Effective
Date, and all continuations, divisionals and continuation-in-part applications
based on MIT Case [**]. This option shall be subject to the rights of any
sponsor of the research leading to the invention.

      2.3 LICENSEE agrees that LICENSED PRODUCTS leased or sold in the United
States shall be, to the extent legally and practically feasible, manufactured
substantially in the United States.

      2.4 M.I.T. and Children's Hospital reserves the right to practice under
the PATENT RIGHTS for its own noncommercial research purposes.

      2.5 LICENSEE shall have the right to enter into sublicensing agreements
for the rights, privileges and licenses granted hereunder. Upon any termination
of this Agreement, sublicensees' rights shall also terminate, subject to
Paragraph 13.6 hereof


                                      -6-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

      2.6 LICENSEE agrees that any sublicenses granted by it shall provide that
the obligations to M.I.T. of Articles 2, 5, 7, 8, 9, 10, 12, 13, and 15 of this
Agreement shall be binding upon the sublicensee as if it were a party to this
Agreement. LICENSEE further agrees to attach copies of these Articles to
sublicense agreements.

      2.7 LICENSEE agrees to forward to M.I.T. a copy of any and all sublicense
agreements promptly upon execution by the parties.

      2.8 The license granted hereunder shall not be construed to confer any
rights upon LICENSEE by implication, estoppel or otherwise as to any technology
not described in any patent or patent application in the PATENT RIGHTS or
addable to the PATENT RIGHTS pursuant to Paragraph 2.2 hereof

      2.9 M.I.T. also grants to LICENSEE a nonexclusive worldwide right and
license to use any unpublished know-how and data owned or controlled by M.I.T.
and/or Children's Hospital as of the date of this Agreement required to practice
the rights granted in Paragraphs 2.1 and 2.2 hereof, and M.I.T. shall make such
know-how and data available to LICENSEE upon request to the extent practicable.

      2.10 Special Provisions Relating to [**] PATENT RIGHTS. Pursuant to the
provisions of Paragraph 2.1 hereof M.I.T. has granted LICENSEE rights to the
[**] PATENT RIGHTS in the FIELD OF USE defined in Paragraph 1.8 hereof With
respect to the [**] PATENT RIGHTS only, M.I.T. and LICENSEE further agree as
follows:

          (a) M.I.T. hereby grants to LICENSEE exclusive rights to the [**]
              PATENT RIGHTS only, in all other fields of use, under the terms
              and conditions of this Agreement.


                                      -7-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

          (b) Should M.I.T. or LICENSEE receive a written request from a capable
              third party for a license to use the [**] PATENT RIGHTS in a field
              of use other than the FIELD OF USE defined in Paragraph 1.8
              hereof, which does not compete with the LICENSED PRODUCTS or
              LICENSED SERVICES already offered for sale by LICENSEE or in the
              process of being developed so as to be available for sale within
              [**] as demonstrated by LICENSEE to the reasonable satisfaction of
              M.I.T., LICENSEE agrees to negotiate in good faith to grant a
              sublicense to said third party. If such negotiation has not been
              successfully completed within [**] from the date LICENSEE first
              receives such request, M.I.T. shall have the right to grant a
              license to said third party for said field of use under
              substantially similar, or less favorable, terms to those contained
              herein. If M.I.T. grants a license under this provision, M.I.T.
              agrees to share [**] Percent ([**]%) of its Net Royalties (defined
              as royalties and license fees after the deduction of (1) a [**]
              Percent ([**]%) administrative fee, and (2) a [**] Percent ([**]%)
              inventors payment) with LICENSEE.

                           ARTICLE 3 - DUE DILIGENCE

      3.1 LICENSEE shall use its reasonable best efforts to bring LICENSED
PRODUCTS and/or LICENSED SERVICES to market through a diligent development
program for exploitation of the PATENT RIGHTS.

      3.2 In addition:


                                      -8-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

          (a) LICENSEE shall use its best efforts to introduce the first
              LICENSED PRODUCT or LICENSED SERVICE to commercial sale by [**].

          (b) LICENSEE shall use its best efforts to introduce to market
              additional LICENSED PRODUCTS or LICENSED SERVICES within [**] of
              demonstration of the scientific and technical feasibility of that
              particular LICENSED PRODUCT or LICENSED SERVICE, the demonstration
              of its clinical effectiveness, and the receipt of required
              approvals (if any are required) of regulatory authorities, or,
              within [**] of the demonstration of scientific, technical and
              clinical feasibility to complete a sublicense agreement for the
              marketing of the LICENSED PRODUCT or LICENSED SERVICE with a
              competent third party that shall commit the third party to use its
              best efforts to bring the LICENSED PRODUCT or LICENSED SERVICE to
              market within [**] of the sublicense agreement.

      3.3 LICENSEE acknowledges that the primary objective of M.I.T. and
Children's Hospital with respect to the technology of this License Agreement is
to promote development and marketing of LICENSED PRODUCTS and LICENSED SERVICES
for the public good. Toward this end, M.I.T. shall have the right to terminate
this Agreement pursuant to Paragraph 13.3 hereof if LICENSEE fails to perform in
accordance with Paragraph s 3.1 or 3.2(a) above or if LICENSEE suspends its
diligence in performance of any of the development obligations of this Agreement
for more than [**] because of business circumstances such as lack of funds,
merger, acquisition, or the like. Failure to perform in accordance with
Paragraph 3.3 (b) here of shall only give M.I.T. the right to take back rights
granted hereunder as to the particular LICENSED PRODUCT or LICENSED SERVICE, and
products or services which are directly


                                      -9-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

competitive to, or replacements of that LICENSED PRODUCT or LICENSED SERVICE,
not introduced or sublicensed, or at M.I.T.'s discretion the fight to bring a
willing sublicense prospect to LICENSEE. However, if LICENSEE can demonstrate to
the satisfaction of M.I.T., at M.I.T.'s sole discretion, that circumstances
beyond LICENSEE's control precluded LICENSEE from fulfilling its diligence
obligations, and that it is unlikely that any third party could overcome these
circumstances better than LICENSEE, then M.I.T. shall not exercise its
termination rights under this Paragraph for [**] from the date at which M.I.T.
gives notice of termination and if LICENSEE reestablishes diligence towards its
objectives during this [**] period, any prior lack of diligence will be deemed
cured.

                             ARTICLE 4 - ROYALTIES

      4.1 For the rights, privileges and license granted hereunder, LICENSEE has
paid to M.I.T. a License Issue Fee of [**] Dollars ($[**]) and issued to M.I.T.
[**] shares of its Common Stock par value $0.01 per share, and shall pay
additional royalties to M.I.T. in the manner hereinafter provided to of the
PATENT RIGHTS or until this Agreement shall be terminated:

          (a) Licensee Maintenance Fees of [**] Dollars ($[**]) per year payable
              on June 1, 1996 and on June 1 of each year thereafter; provided,
              however, that Running Royalties subsequently due on NET SALES for
              said year, if any, shall be creditable against the Licensee
              Maintenance Fee for said year. License Maintenance Fees paid in
              excess of Running Royalties shall not be creditable to Running
              Royalties for future years.

          (b) Running Royalties in an amount equal to [**] Percent ([**]%) of
              NET SALES of the LICENSED PRODUCTS and LICENSED SERVICES leased or
              sold by and/or for LICENSEE.

          (c) Royalties representing a share of sublicensing revenue received by
              LICENSEE for LICENSED PRODUCTS or LICENSED SERVICES sold by the
              sublicensee equal to:


                                      -10-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

              (i)     [**] Percent ([**]%) if only the PATENT RIGHTS are
                      sublicensed; or

              (ii)    [**] Percent ([**]%) if the sublicense revenue includes
                      revenue received for the PATENT RIGHTS sublicensed in
                      conjunction with products developed by LICENSEE and/or
                      substantial technology developed by LICENSEE;

                      but in no event shall royalties be less than [**] percent
                      ([**]%) of the NET SALES of the LICENSED PRODUCTS or
                      LICENSED SERVICES sold by sublicensee;

                      provided further that an assignment pursuant to paragraph
                      11 of a this Agreement shall not obligate LICENSEE to make
                      payments to M.I.T. under this paragraph 4.1(c).

          (d) (i)     Except as set forth in Paragraph 4.1(d)(iii) hereof,
                      M.I.T. shall be [**] regarding (A) the [**] by LICENSEE of
                      [**] of [**] of its [**]; (B) the [**] of any [**],[**] of
                      [**] or other [**] of LICENSEE [**] or [**] for, or
                      carrying or accompanied by [**],[**] or [**] to, any [**]
                      of any [**] of its [**]; or (C) the [**] of any [**] of
                      [**] to or [**], or any [**] or [**] for the [**] of, any
                      of the foregoing [**] (the [**] set forth in (A), (B) and
                      (C) herein referred to as the "[**]").

              (ii)    Prior to any [**] described in Paragraph 4.1(d)(i) hereof,
                      LICENSEE shall give M.I.T. at least 30 days' notice, and
                      M.I.T. shall have the right by notifying LICENSEE within
                      15 days after receipt of the notice regarding the
                      [**],[**] or [**], to [**], on the [**] as those of the
                      [**], a [**] of such [**] equal to M.I.T.'s [**] of [**]
                      of LICENSEE on a record date not more than 30 days prior
                      to such [**],[**] or [**]. The price or prices for such
                      [**] shall not be less favorable to M.I.T. than the price
                      or prices at which such [**] are proposed to be [**] to
                      others, without deduction of the expenses of, and
                      compensation for, the [**],[**] of such [**] by [**] or
                      [**] as may be paid by LICENSEE.

              (iii)   Notwithstanding anything contained herein to the contrary,
                      the provisions of Paragraphs 4.1(d)(i) and (ii) hereof
                      shall not apply to the issuance, sale or grant by LICENSEE
                      of any Securities (A) to a bank or other financial
                      institution in connection with the incurrence of bona fide
                      indebtedness by LICENSEE or (B) as compensation to
                      persons, including employees, officers, directors, agents
                      and consultants of LICENSEE, pursuant to employment or
                      consulting contracts approved by the Board of Directors of
                      LICENSEE or specific resolutions or benefit plans adopted
                      by the Board of Directors of LICENSEE.


                                      -11-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

              (iv)    M.I.T. may transfer [**] Percent ([**]%) of its [**]
                      to purchase Securities as provided herein to Children's
                      Hospital.

          (e) For the additional rights relating to [**] PATENT RIGHTS granted
              pursuant to Paragraph 2.10 hereof, LICENSEE has paid to M.I.T. a
              License Fee of [**] Dollars ($[**] and shall pay to M.I.T.:

              (i)     License Maintenance Fees of [**] Dollars ($[**]) per year,
                      due on June 1, 1997 and each June 1 thereafter, in
                      addition to the License Maintenance Fees due under
                      Paragraph 4.1(b) hereof Running Royalties for all fields
                      of use for all LICENSED PRODUCTS and LICENSED PROCESSES
                      under this Agreement shall be creditable against this
                      License Maintenance Fee as specified in Paragraph 4.1(b)
                      hereof

              (ii)    Running Royalties in all fields of use shall be the same
                      as specified in Paragraph 4.1(c) hereof.

      4.2 All payments due hereunder shall be subject to deduction of taxes or
other fees which may be imposed by any government which are paid by LICENSEE.

      4.3 No multiple royalties shall be payable because any LICENSED PRODUCT,
its manufacture, use, lease or sale are or shall be covered by more than one
PATENT RIGHTS patent application or PATENT RIGHTS patent licensed under this
Agreement.

      4.4 Royalty payments shall be paid in United States dollars in Cambridge,
Massachusetts, or at such other place as M.I.T. may reasonably designate
consistent with the laws and regulations controlling in any foreign country. If
any currency conversion shall be required in connection with the payment of
royalties hereunder, such conversion shall be made by using the exchange rate
prevailing at the Chase Manhattan Bank (N.A.) on the last business day of the
calendar quarterly reporting period to which such royalty payments relate.

      4.5 If no patent claims to M.I.T. Case [**] of the PATENT RIGHTS are
allowed in the United States by January 1, 1997, then no royalties or license
maintenance fees which mature after said date shall be due unless and until such
claims are allowed, except if the LICENSED PRODUCT or SERVICE falls under an
issued patent of another M.I.T. Case licensed in this


                                      -12-
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  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

Agreement. If such claims to M.I.T. Case [**] are subsequently allowed after
such suspension of royalties, Running Royalties shall thereafter be due on NET
SALES of LICENSED PRODUCTS or SERVICES sold after said allowance of claims, and
License Maintenance Fees that mature after said allowance of claim shall also be
due.

      4.6 If after January 1, 1997 claims have been allowed but said claims are
not as broad as the first claim of USSN [**] of Case [**] (as filed), then
M.I.T. and LICENSEE shall meet to renegotiate the Royalty Rates and License
Maintenance Fees in good faith based on the claims that have been allowed and
claims of other patent that have been added to the PATENT RIGHTS of this
Agreement. Similarly, if at any time prior to January 1, 1997 all U.S. patent
prosecution on Case [**] is completed or abandoned, such that no unallowed or
unissued claims are pending, and no claim has been allowed or issued that is as
broad as the first claim of USSN [**] of Case [**] (as filed), then M.I.T. and
LICENSEE shall meet at that time to renegotiate the Royalty Rates and License
Maintenance Fees based on the claims that have been allowed and claims of other
patents which have been added to the PATENT RIGHTS of this Agreement.

      4.7 In the event LICENSEE is required to make payments (including without
limitation royalties, option fees or license fees) to one or more third parties,
other than M.I.T., its affiliates, successors or assigns, to obtain a license or
similar right necessary to make, use or sell LICENSED PRODUCTS or to practice or
otherwise make use of the LICENSED PROCESSES, LICENSEE may deduct [**] Percent
([**]%) of such payments from royalties thereafter payable to M.I.T., provided,
however, that in no event shall the royalties due M.I.T. be reduced by more than
[**] ([**]) nor reduced below [**] Percent ([**]%) of NET SALES of the LICENSED
PRODUCTS and LICENSED SERVICES.


                                      -13-
<PAGE>

                        ARTICLE 5 - REPORTS AND RECORDS

      5.1 LICENSEE shall keep full, true and accurate books of account
containing all particulars that may be necessary for the purpose of showing the
amounts payable to M.I.T. hereunder. Said books of account shall be kept at
LICENSEE's principal place of business or the principal place of business of the
appropriate division of LICENSEE to which this Agreement relates. Said books and
the supporting data shall be open at all reasonable times and upon reasonable
notice for three (3) years following the end of the calendar year to which they
pertain, to the inspection of a certified public accountant designated by M.I.T.
for the sole purpose of verifying LICENSEE's royalty statement or compliance in
other-respects with this Agreement.

      5.2 Prior to the year in which LICENSEE makes the first commercial sale of
a LICENSED PRODUCT or LICENSED SERVICE, LICENSEE shall deliver yearly reports to
M.I.T. within sixty (60) days after the end of each year giving the particulars
of the business conducted by LICENSEE and its sublicensees during the preceding
year which are pertinent. After the first commercial sale of a LICENSED PRODUCT
or LICENSED SERVICE such reports shall be delivered quarterly within sixty (60)
days after the end of each calendar quarter for the preceding quarter. All such
reports shall give particulars of the business pertinent to a royalty accounting
under this Agreement, including at a minimum:

          (a) number of LICENSED PRODUCTS and LICENSED SERVICES manufactured and
              sold by LICENSEE and all sublicensees;

          (b) total billings for LICENSED PRODUCTS and LICENSED SERVICES sold by
              LICENSEE and all sublicensees;

          (c) revenue received from sublicensees for LICENSED PRODUCTS and
              LICENSED SERVICES;

          (d) deductions applicable as provided in Paragraph 1.6 hereof,


                                      -14-
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  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

          (e) total royalties due; and

          (f) names and addresses of all sublicensees of LICENSEE.

      5.3 With each such report submitted, LICENSEE shall pay to M.I.T. the
royalties due and payable under this Agreement. If no royalties shall be due,
LICENSEE shall so report.

      5.4 On or before the ninetieth (90th) day following the close of
LICENSEE's fiscal year, LICENSEE shall provide M.I.T. with LICENSEE's certified
financial statements for the preceding fiscal year including, at a minimum, a
Balance Sheet and an Operating Statement.

      5.5 The royalty payments set forth in this Agreement and amounts due under
Article 6 shall, if overdue, bear interest until payment at a per annum rate
[**] percent ([**]%) above the prime rate in effect at the Chase Manhattan Bank
(N.A.) on the due date. The payment of such interest shall not foreclose M.I.T.
from exercising any other rights it may have as a consequence of the lateness of
any payment.

                         ARTICLE 6 - PATENT PROSECUTION

      6.1 M.I.T. and Children's Hospital shall apply for, seek prompt issuance
of, and maintain during the term of this Agreement the PATENT RIGHTS in the
United States and in those foreign countries listed in Appendix B hereto and in
any other foreign country at LICENSEE's request. Appendix B may be amended by
verbal agreement of both parties, such agreement to be confirmed in writing
within ten (10) days. The prosecution, filing and maintenance of all PATENT
RIGHTS patents and applications shall be the primary responsibility of LICENSEE
to the extent that such primary responsibility has not been previously granted
by M.I.T. to Advanced Tissue Sciences, Inc. ("ATS") provided, however, that
MI.T. and Children's Hospital shall have reasonable opportunities to advise
LICENSEE and shall cooperate with LICENSEE in such prosecution, filing and
maintenance, and further provided that LICENSEE shall not abandon any
substantive claims in the PATENT RIGHTS


                                      -15-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

without prior permission of M.I.T. or Children's Hospital. In cases where ATS
has the primary responsibility for such prosecution, M.I.T. and Children's
Hospital agree to grant to LICENSEE their rights to advise ATS on prosecution
matters that in LICENSEE's view could affect LICENSEE's rights in the PATENT
RIGHTS in the FIELDS OF USE.

      6.2 LICENSEE shall reimburse M.I.T. (or Children's Hospital as
appropriate) for filing, prosecution and maintenance of the following Patent
Rights:

          (a) For M.I.T. Case Nos. [**],[**],[**],[**],[**],[**],[**] and
              [**];[**] percent ([**]%) of all patent costs incurred for these
              cases before the Effective Date of this Agreement and during any
              period in which ATS is licensed. to these cases. If the ATS
              license is terminated, LICENSEE shall reimburse M.I.T. for all
              patenting expenses for these cases incurred thereafter if licensed
              only to LICENSEE, and a reasonable share of patenting costs during
              any period when there are other licenses to said Patent Rights. To
              the best of M.I.T.'s knowledge, all such costs as have been
              incurred prior to the Effective Date of this Agreement are set
              forth in a letter from M.I.T. to LICENSEE dated the Effective
              Date;

          (b) For M.I.T. Case Nos. [**],[**],[**], and [**]:[**] Percent ([**]%)
              of all patenting costs, whether incurred before or during the
              period of this Agreement. To the best of M.I.T.'s knowledge, all
              such costs as have been incurred prior to the Effective Date of
              this Agreement are set forth in a letter from M.I.T. to LICENSEE
              dated the Effective Date;

          (c) For M.I.T. Case Nos. [**],[**],[**],[**] and [**], and any new
              PATENT RIGHTS added pursuant to Paragraph 2.2 hereof or otherwise
              by amendment: [**] Percent ([**]%) of all patenting costs
              (including those prior to licensing) if licensed only to LICENSEE,
              and a reasonable share of patenting costs during any period when
              there are other licensees to said Patent Rights.

          (d) For M.I.T. Case [**]: It is understood that MIT has another
              licensee to this case, outside the field of use of medical
              applications, who is responsible for patenting costs for this
              case. Said licensee wishes its identity to remain confidential.
              LICENSEE agrees that if this other license is terminated, LICENSEE
              shall be responsible for all patenting costs incurred thereafter.
              Licensee shall also be responsible for all patenting costs for any
              future divisionals, continuations or other derivatives of the
              Patent Rights of this case (if any) which are directed solely to
              medical applications.


                                      -16-
<PAGE>

      6.3 If M.I.T. or a third party licensee decides to discontinue paying the
prosecution or maintenance costs of a case in the PATENT RIGHTS, LICENSEE shall
have the right but not the obligation to assume the patenting costs to prevent
abandonment of the rights to such case.

      6.4 In the event that M.I.T. or a third party licensee does not elect to
file for patent protection on an invention covered by Paragraph 2.2 hereof,
LICENSEE shall have the right to prepare and file appropriate applications on
such inventions in the name of M.I.T, the costs to be borne by LICENSEE in
accordance with Paragraph 6.2(c) hereof

                            ARTICLE 7 - INFRINGEMENT

      7.1 LICENSEE and M.IT. shall inform the other promptly in writing of any
alleged infringement of the PATENT RIGHTS in the FIELDS OF USE by a third party
and of any available evidence thereof.

      7.2 During the term of this Agreement, LICENSEE shall have the right, but
shall not be obligated, to prosecute at its own expense all infringements of the
PATENT RIGHTS in the FIELDS OF USE and, in furtherance of such right, M.I.T.
hereby agrees that LICENSEE may include M.I.T. as a party plaintiff in any such
suit without expense to M.I.T. The total cost of any such infringement action
commenced or defended solely by LICENSEE shall be borne by LICENSEE. No
settlement, consent judgment or other voluntary final disposition of the suit
may be entered into without the consent of M.I.T., which consent shall not
unreasonably be withheld.

      7.3 If within six (6) months after learning of any alleged infringement,
LICENSEE shall have been unsuccessful in persuading the alleged infringer to
desist and shall not have brought and shall not be diligently prosecuting an
infringement action, or if LICENSEE shall notify M.I.T. at anytime prior thereto
of its intention not to bring suit against any alleged infringer, then, and in
those events only, M.I.T. shall have the right, but shall not be obligated, to


                                      -17-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

prosecute at its own expense any infringement of the PATENT RIGHTS, and M.I.T.
may, for such purposes, use the name of LICENSEE as party plaintiff. M.I.T.
shall indemnify LICENSEE against any order for costs that may be made against
LICENSEE in such proceedings. In the event M.I.T. shall undertake the
enforcement and/or defense of the patent rights by litigation, M.I.T. shall keep
any recovery or damages for patent infringement derived therefrom.

      7.4 In the event that LICENSEE shall undertake the enforcement and/or
defense of the PATENT RIGHTS by litigation, LICENSEE may withhold up to [**]
Percent ([**]%) of the payments otherwise thereafter due M.I.T. under Article 4
hereof and apply the same toward reimbursement of up to half of LICENSEE's
expenses, including reasonable attorneys' fees, in connection therewith. Any
recovery of damages by LICENSEE for each such suit shall be applied first in
satisfaction of any unreimbursed expenses and legal fees of LICENSEE relating to
such suit, and next toward reimbursement of M.I.T. for any payments under
Article 4 past due or withheld and applied pursuant to this Article 7. The
balance remaining from any such recovery shall be divided between LICENSEE and
M.I.T. in the proportion of [**]%.

      7.5 In the event that M.I.T. (or any third party licensee) shall undertake
the enforcement and/or defense of the PATENT RIGHTS outside the FIELDS OF USE of
this License Agreement, then LICENSEE shall have the right, at its own expense,
to participate in such enforcement or defense, but shall have no rights to any
compensation derived therefrom, except to the extent LICENSEE's legal costs are
awarded.

      7.6 In the event that a declaratory judgment action alleging invalidity or
noninfringement of any of the PATENT RIGHTS shall be brought against LICENSEE,
M.I.T., at


                                      -18-
<PAGE>

its option, shall have the right within thirty (30) days after commencement of
such action, to intervene and take over the sole defense of the action at its
own expense.

      7.7 In any infringement suit that either party may institute to enforce
the PATENT RIGHTS pursuant to this Agreement, the other party hereto shall, at
the request and expense of the party initiating such suit, cooperate in all
respects and, to the extent possible, have its employees testify when requested
and make available relevant records, papers, information, samples, specimens,
and the like.

      7.8 LICENSEE, during the exclusive period of this Agreement, shall have
the sole right in accordance with the terms and conditions herein to sublicense
any alleged infringer for future use of the PATENT RIGHTS.

                ARTICLE 8 - PRODUCT LIABILITY AND REPRESENTATION

          (a) LICENSEE shall indemnify, defend and hold harmless M.I.T. and
              Children's Hospital, their trustees, officers, medical and
              professional staff, employees, and agents and their respective
              successors, heirs and assigns (the "Indemnities"), against any
              liability, damage, loss or expense (including reasonable
              attorney's fees and expenses of litigation) incurred by or imposed
              upon the Indemnitees or any one of them in connection with any
              claims, suits, actions, demands or judgments arising out of any
              theory of product liability (including, but not limited to,
              actions in the form of tort, warranty, or strict liability)
              concerning any product, process or service made, used or sold
              pursuant to any right or license granted under this Agreement.

          (b) LICENSEE's indemnification under (a) above shall not apply to any
              liability, damage, loss or expense to the extent that it is
              directly attributable to the negligent activities, reckless
              misconduct or intentional rnisconduct of the Indemnitees or if any
              employee of M.I.T. or Children's Hospital shall use a LICENSED
              PRODUCT or LICENSED PROCESS on humans without with the express
              written permission of LICENSEE.

          (c) LICENSEE agrees, at its own expense, to provide attorneys
              reasonably acceptable to the Institution to defend against any
              actions brought or filed against any party indemnified hereunder
              with respect to the subject of indemnity contained herein, whether
              or not such actions are rightfully brought.


                                      -19-
<PAGE>

          (d) This Section 8.1 shall survive expiration or termination of this
              Agreement.

      8.2 Insurance

          (a) Beginning at the time as any such product, process or service is
              being commercially distributed or sold (other than for the purpose
              of obtaining regulatory approvals) by LICENSEE or by a
              sublicensee, affiliate or agent of LICENSEE, LICENSEE shall, at
              its sole cost and expense, procure and maintain comprehensive
              general liability insurance in amounts not less than $2,000,000
              per incident and $2,000,000 annual aggregate and naming the
              Indemnitees as additional insureds. Such comprehensive general
              liability insurance shall provide (i) product liability coverage
              and (ii) broad form contractual liability coverage for LICENSEE's
              indemnification under Section 8.1 of this Agreement. If LICENSEE
              elects to self-insure all or part of the limits described above
              (including deductibles or retentions which are in excess of
              $250,000 annual aggregate), such self-insurance program must be
              acceptable to M.I.T. and Children's Hospital and the Risk
              Management Foundation of the Harvard Medical Institutions, Inc.
              The minimum amount of insurance coverage required under this
              Section 8.2 shall not be construed to create a limit of LICENSEE's
              liability with respect to its indemnification under Section 8.1 of
              this Agreement.

          (b) LICENSEE shall provide M.I.T. with written evidence of such
              insurance upon request of M.I.T. LICENSEE shall provide M.I.T.
              with written notice at least fifteen (15) days prior to the
              cancellation, non-renewal or material change in such insurance; if
              LICENSEE does not obtain replacement insurance providing
              comparable coverage within such fifteen (15) day period, M.I.T.
              shall have the right to terminate this Agreement effective at the
              end of such fifteen (15) day period without notice of any
              additional waiting periods.

          (c) LICENSEE shall maintain such comprehensive general liability
              insurance during

              (i)   the period that any such product process or service is being
                    commercially distributed or sold (other than for the purpose
                    of obtaining regulatory approvals) by LICENSEE or by a
                    sublicensee, affiliate or agent of LICENSEE, and

              (ii)  a reasonable period after the period referred to in (c)(i)
                    above which in no event shall be less than fifteen (15)
                    years.

          (d) This Section 8.2 shall survive expiration or termination of this
              Agreement.


                                      -20-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

      8.3 M.I.T. represents and warrants that it owns the United States and
corresponding foreign patents and applications included within the PATENT RIGHTS
of Appendix A, and that, to the best of its knowledge, the claims of the PATENT
RIGHTS of Appendix A are valid, patentable and enforceable. M.I.T. further
represents and warrants that it co-owns certain of the PATENT RIGHTS with
Children's Hospital, and that Children's Hospital has empowered M.I.T.
unilaterally to grant the licenses hereunder as evidenced by the agreement
attached hereto as Appendix C. M.I.T. represents and warrants that it is free of
any obligations preventing M.I.T. from providing to LICENSEE the rights and
licenses granted herein. M.I.T.'s and Children's Hospital's total liability for
such representations and those of Paragraph 8.4 hereof is limited to the extent
of patent costs, license fees, license maintenance fees, and royalties paid to
M.I.T. by LICENSEE under this Agreement.

      8.4 M.I.T. hereby represents that, to the best of its knowledge as of the
Effective Date of this Agreement, there do not exist any M.I.T. or Children's
Hospital patents or pending patents, other than the PATENT RIGHTS of this
Agreement which would be infringed by the practice of the PATENT RIGHTS of this
Agreement as taught in the PATENT RIGHTS of M.I.T. Case [**] as originally filed
or which would otherwise prevent the practice of any of the claims described in
the patents and patent applications fisted in M.I.T. Case [**] as originally
filed. If, however, such M.I.T. or Children's Hospital patents or patent
applications are subsequently found to have existed prior to that date, or if
such M.I.T. or Children's Hospital patents or patent applications exist during
the term of the license of PATENT RIGHTS granted hereunder, M.I.T. shall grant
to LICENSEE, to the extent then-existing agreements with third parties allow, a
fully paid-up nonexclusive license to such patents and/or patent applications,
to the extent necessary for the practice of the PATENT RIGHTS of this Agreement.


                                      -21-
<PAGE>

      8.5 EXCEPT AS OTHERWISE EXPRESSLY SET FORTH IN THIS AGREEMENT, M.I.T.
MAKES NO REPRESENTATIONS AND EXTENDS NO WARRANTIES OF ANY KIND, EITHER EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE, AND VALIDITY OF PATENT RIGHTS CLAIMS, ISSUED OR
PENDING.

                          ARTICLE 9 - EXPORT CONTROLS

      It is understood that M.I.T. is subject to United States laws and
regulations controlling the export of technical data, computer software,
laboratory prototypes and other commodities (including the Arms Export Control
Act, as amended, and the Export Administration Act of 1979), and that its,
obligations hereunder are contingent on compliance with applicable United States
export laws and regulations. The transfer of certain technical data and
commodities may require a license from the cognizant agency of the United States
Government and/or written assurances by LICENSEE that LICENSEE shall not export
data or commodities to certain foreign countries without prior approval of such
agency. M.I.T. neither represents that a license shall not be required nor that,
if required, it shall be issued.

                         ARTICLE 10 - NON-USE OF NAMES

      LICENSEE shall not use the names or trademarks of the Massachusetts
Institute of Technology or Children's Hospital, nor any adaption thereof nor the
names of any of their employees; in any advertising, promotional or sales
literature without prior written consent obtained from M.I.T., Children's
Hospital, or said employee, in each case, except that LICENSEE may state that it
is licensed by M.I.T. under one or more of the patents and/or applications
comprising the PATENT RIGHTS.


                                      -22-
<PAGE>

                            ARTICLE 11 - ASSIGNMENT

      This Agreement may be assigned only in connection with (a) a change in
name or legal status of LICENSEE that does not affect the nature of its business
activities or (b) the sale of substantially all the assets of the business to
which the PATENT RIGHTS relates or a separable business unit related to a
particular LICENSED PRODUCT or LICENSED SERVICE with the written permission of
M.I.T., which shall not be unreasonably withheld, or (c) otherwise with the
written permission of M.I.T., which shall not be unreasonably withheld.

                        ARTICLE 12 - DISPUTE RESOLUTION

      12.1 Except for the right of either party to apply to a court of competent
jurisdiction for a temporary restraining order, a preliminary injunction, or
other equitable relief to preserve the status quo or prevent irreparable harm,
any and all claims, disputes or controversies arising under, out of, or in
connection with the Agreement including any dispute relating to patent validity
or infringement, which the parties shall be unable to resolve within sixty (60)
days shall be mediated in good faith. The party raising such dispute shall
promptly advise the other party of such claim, dispute or controversy in a
writing which describes in reasonable detail the nature of such dispute. By not
later than five (5) business days after the recipient has received such notice
of dispute, each party shall have selected for itself a representative who shall
have the authority to bind such party, and shall additionally have advised the
other party in writing of the name and title of such representative. By not
later than ten (10) business days after the date of such notice of dispute, such
representatives shall schedule a date for a mediation hearing with the Cambridge
Dispute Settlement Center or Endispute Inc. in Cambridge, Massachusetts. The
parties shall enter into good faith mediation and shall share the costs equally.
If the representatives of the parties have not been able to resolve the dispute
within fifteen (15) business days after such mediation hearing, the parties
shall have the right to pursue any other


                                      -23-
<PAGE>

remedies legally available to resolve such dispute in either the Courts of the
Commonwealth of Massachusetts or in the United States District Court for the
District of Massachusetts, to whose jurisdiction for such purposes M.I.T. and
LICENSEE each hereby irrevocably consents and submits.

      12.2 Notwithstanding the foregoing, nothing in this Article shall be
construed to waive any rights or timely performance of any obligations existing
under this Agreement.

                            ARTICLE 13 - TERMINATION

      13.1 Unless sooner terminated in a manner herewith provided, this
Agreement and the licenses herein granted shall continue in force until the
last-to-expire of the patents included in the PATENT RIGHTS.

      13.2 Should LICENSEE fail to make any payment whatsoever due and payable
to M.I.T. hereunder, M.I.T. shall have the right to terminate this Agreement
effective on sixty (60) days' prior written notice, unless LICENSEE shall make
all such payments to M.I.T. within said sixty (60) day period. Upon the
expiration of the sixty (60) day period, if LICENSEE shall not have made all
such payments to M.I.T. or, in the case of a dispute as to royalties due,
commenced the dispute resolution procedures contemplated by Article 12 hereof,
the rights, privileges and license granted hereunder shall automatically
terminate.

      13.3 Upon any material breach or default of this Agreement by LICENSEE,
other than those occurrences set out in Paragraph 13.1 and 13.2 hereof, which
shall always take precedence in that order over any material breach or default
referred to in this Paragraph 13.3, M.I.T. shall have the right to terminate
this Agreement and the rights, privileges and license granted hereunder
effective on ninety (90) days prior written notice to LICENSEE. Such termination
shall become automatically effective unless LICENSEE shall have cured any such
material breach or default prior to the expiration of the ninety (90) day
period.


                                      -24-
<PAGE>

      13.4 LICENSEE shall have the right to terminate this Agreement at any time
on ninety (90) days' prior written notice to M.I.T., and upon payment of all
amounts due M.I.T. through the effective date of the termination.

      13.5 Upon termination of this Agreement for any reason, nothing herein
shall be construed to release either party from any obligation that matured
prior to the effective date of such termination. LICENSEE and any sublicensee
thereof may, however, after the effective date of such termination, sell all
LICENSED PRODUCTS and LICENSED SERVICES, and complete LICENSED PRODUCTS in the
process of manufacture at the time of such termination and sell the same,
provided that LICENSEE shall pay to M.I.T. the Running Royalties thereon as
required by Article 4 hereof and shall submit the reports required by Article 5
hereof on the sales of LICENSED PRODUCTS and LICENSED SERVICES.

      13.6 Upon termination of this Agreement for any reason, any sublicense not
then in default shall have the right to seek a license from M.I.T. M.I.T. agrees
to negotiate such licenses in good faith under reasonable terms and conditions.

                         ARTICLE 14 - PAYMENTS, NOTICES
                            AND OTHER COMMUNICATIONS

      Any payment, notice or other communication pursuant to this Agreement
shall be sufficiently made or given on the date of mailing if sent to such party
by certified first class mail, postage prepared, addressed to it at its address
below or as it shall designate by written notice given to the other party:

In the case of M.I.T.:

                 Director
                 Technology Licensing Office
                 Massachusetts Institute of Technology
                 Room E32-300
                 Cambridge, Massachusetts 02139


                                      -25-
<PAGE>

In the case of LICENSEE:

                 Mr.  Bruce Parker
                 President
                 Parker Medical Assoc.
                 2401 Distribution Street
                 Charlotte, N.C.  28203

                     ARTICLE 15 - MISCELLANEOUS PROVISIONS

      15.1 This Agreement shall be construed, governed, interpreted and applied
in accordance with the laws of the Commonwealth of Massachusetts, U.S.A., except
that questions affecting the construction and effect of any patent shall be
determined by the law of the country in which the patent was granted.

      15.2 The parties hereto acknowledge that this Agreement sets forth the
entire Agreement and understanding of the parties hereto as to the subject
matter hereof, and shall not be subject to any change or modification except by
the execution of a written instrument subscribed to by the parties hereto.

      15.3 The provisions of this Agreement are severable, and in the event that
any provisions of this Agreement shall be determined to be invalid or
unenforceable under any controlling body of the law, such invalidity or
unenforceability shall not in any way affect the validity or enforceability of
the remaining provisions hereof.

      15.4 LICENSEE agrees to mark the LICENSED PRODUCTS sold in the United
States with all applicable United States patent numbers. All LICENSED PRODUCTS
shipped to or sold in other countries shall be marked in such a manner as to
conform with the patent laws and practice of the country of manufacture or sale.

      15.5 The failure of either party to assert a right hereunder or to insist
upon compliance with any term or condition for this Agreement shall not
constitute a waiver of that right or excuse a similar subsequent failure to
perform any such term or condition by the other party.


                                      -26-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

      15.6 A party to this Agreement shall be excused from liability for delay
in the performance of any of its obligations hereunder if such delay is due to
causes beyond its reasonable control including, without limitation, acts of God,
fires, earthquakes, strikes and labor disputes, acts of war, or intervention of
any governmental authority, but any such delay or failure shall be remedied by
such party as soon as is reasonably possible.

      15.7 Special Provisions Relating to AMS. M.I.T. has reviewed the Research
and Development Agreement (the "R&D Agreement") and the Supply and Marketing
Agreement (the "S&M Agreement") between LICE . NSEE and American Medical
Systems, Inc. ("AMS") (copies of which have been delivered to M.I.T.), and:

          (a) M.I.T. hereby agrees that AMS is deemed to be a sublicensee under
              this Agreement and that the licenses granted to AMS pursuant to
              the R&D Agreement and the S&M Agreement meet the sublicense
              requirements of the License Agreement.

          (b) For purposes of transactions and other matters under or to the
              extent affecting the rights and obligations of the parties under
              the R&D Agreement and the S&M Agreement only, the provisions of
              this Agreement are amended and supplemented as follows:

              (i)     "NET SALES" has the same definition as Net Sales under the
                      S&M Agreement.

              (ii)    With respect to distribution of LICENSED PRODUCTS and
                      LICENSED SERVICES (as such terms are defined in this
                      Agreement) under or pursuant to the S&M Agreement or
                      Section 9.4 of the R&D Agreement, Running Royalties will
                      be equal to the greater of [**] percent ([**]%) of Net
                      Sales, as defined in the S&M Agreement or [**] ([**]) of
                      royalties accrued to LICENSEE on such Net Sales, and no
                      royalties will be due on the Transfer Price, as defined in
                      the S&M Agreement paid to LICENSEE therefor. Annual and
                      quarterly reports under Paragraph 5.2 hereof will be due
                      ninety (90) days after the end of the applicable calendar
                      year or quarter. AMS financial statements will be
                      sufficient for purposes of this Agreement if certified by
                      the chief financial officer or controller of AMS as
                      prepared in accordance with generally accepted accounting
                      principles consistently applied by AMS and if limited to
                      transactions resulting in Running Royalties.


                                      -27-
<PAGE>

              (iii)   In the event M.I.T. issues any notice under Paragraph 2.2,
                      13.2 or 13.3 hereof, M.I.T. will simultaneously deliver a
                      copy thereof to AMS by certified first class mail, postage
                      prepaid, addressed as follows or as otherwise designated
                      by AMS by written notice to M.I.T.:

                                   American Medical Systems, Inc.
                                   10700 Bren Road West
                                   Minneapolis, Minnesota 55343
                                   Attn: David Booth, President

              (iv)    M.I.T. may terminate this Agreement pursuant to Paragraph
                      13.2 or 13.3 hereof with respect to the applications
                      within the FIELD OF USE (as defined in this Agreement)
                      other than tissue engineering applications in the human
                      urological field without terminating this Agreement with
                      respect to tissue engineering applications in the human
                      urological field within the FIELD OF USE. In the event of
                      any failure to make any payment under this Agreement or
                      other material breach or default of this Agreement that
                      does not relate to tissue engineering applications in the
                      human urological field within the FIELD OF USE, M.I.T.
                      will not terminate this Agreement with respect to tissue
                      engineering applications in the human urological field
                      within the FIELD OF USE.

              (v)     Any termination of this Agreement with respect to tissue
                      engineering applications in the human urological field
                      within the FIELD OF USE by LICENSEE pursuant to Paragraph
                      13.4 hereof requires the prior written consent of AMS to
                      be effective.

              (vi)    This Agreement will not be modified in any manner
                      adversely affecting tissue engineering applications in the
                      human urological field within the FIELD OF USE without the
                      prior written consent of AMS, which is an intended third
                      party beneficiary of the provisions of this Paragraph 15.7
                      as so amended and supplemented as a sublicensee hereunder.
                      Without limiting the generality of the foregoing, any
                      modification of this Agreement by addition of patent
                      rights under Paragraph 2.2 hereof will not require such
                      written consent.



                                      -28-
<PAGE>
      IN WITNESS WHEREOF, the parties have duly executed this Amended and
Restated Agreement the day and year set forth below.

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

By /s/ Lita Nelson
   ---------------
Name Lita L. Nelson
     --------------
Title Director Technology Licensing Office
      ------------------------------------

Date: July 1, 1996


REPROGENESIS, INC.

By /s/ A. Bruce Parker
   -------------------
Name: A. Bruce Parker
Title: President

Date: July 1, 1996

                                      -29-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                                         APPENDIX

UNITED STATES PATENT RIGHTS

M.I.T. Case [**]
"[**]"
By Joachim Kohn and Robert S. Langer
U.S. Patent[**]         Issued [**]

M.I.T. Case [**]
"[**]"
By Joachim Kohn and Robert S. Langer
U.S.  Patent [**]       Issued [**]

M.I.T. Case [**]
"[**]"
By Joseph P. Vacanti and Robert S. Langer
U.S.S.N. [**]           Filed [**]
U.S.S.N. [**]           Filed [**]
U.S.S.N. [**]           Filed [**]
PCT/US[**]              Filed [**]
JAP S.N. [**]           Filed [**]
EPC S.N. [**]           Filed [**]

M.I.T. Case [**]
"[**]"
By Abraham J. Domb, Robert S. Langer, Ernest G. Cravalho, Gerson Gollomb, Edith
Mathiowitz and Cato T. Laurencin
U.S.S.N. [**]           Filed [**]
U.S.S.N. [**]           Filed [**]
JP S.N.___              Filed [**]
EPC [**]                Filed [**]
CAN [**]                Filed [**]

M.I.T. Case [**]
"[**]"
By Robert S. Langer, Charles A. Vacanti and Joseph P. Vacanti
U.S. Patent [**]        Issued [**]
U.S.S.N. [**]           Filed [**]
PCT S.N. PCT IUS[**]    Filed [**]

M.I.T. Case [**]
"[**]"
By Lynt Johnson, Robert S. Langer and Joseph P. Vacanti
U.S.S.N. [**]           Filed [**]
U.S.S.N. [**]           Filed [**]
NO S.N.                 Filed [**]


                                      -30-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

KR S.N.                 Filed [**]
JP S.N. 1-[**]          Filed [**]
F1 S.N.                 Filed [**]
EPC S.N. [**]           Filed [**]
CAN S.N. [**]           Filed [**]
AU S.N. [**]            Filed [**]

M.I.T. Case [**]
"[**]"
By Robert S. Langer, Antonios G. Mikos and Georgios Sarakfnos
To be filed at M.I.T.'s discretion.

M.I.T. Case No. [**]
"[**]"
By Robert S. Langer, Jr. and Joseph P. Vacanti
U.S.S.N. [**]           Filed [**]
PCT S.N. PCT/LJS/[**]   Filed [**]

M.I.T. Case No. [**] (CMCC #[**])
"[Neomorphogenesis of Urological Structures In Vivo From Cell]"
By Anthony Atala, Michael R. Freeman, Robert S. Langer and Joseph Vacanti
U.S.S.N. [**]           Filed [**]
U.S.S.N. [**]           Filed [**]
PCT S.N. PCT/US[**]     Filed [**]

M.I.T. Case No. [**] (CMCC [**])
"[**]"
By J. Vacanti and R. Langer

M.I.T. Case No. [**] (CMCC [**])
"[**]"
By J. Vacanti, J. Upton and R. Ortiz-Colberg

M.I.T. Case No. [**] (CMCC [**])
"[**]"
By K. Paige, L Cima, T. Atala and C. Vacanti
U.S.S.N. [**]           Filed [**]
PCT S.N. PCT/US[**]     Filed [**]
JAP S.N. [**]           Filed [**]
EPC S.N. [**]           Filed [**]
CAN S.N. [**]           Filed [**]
AUS S.N. [**]           Filed [**]

M.I.T. Case No. [**] (CMCC [**])
"[**]"
By A. Atala, A. Vacanti, L. Cima, and J. Vacanti


                                      -31-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

M.I.T Case No. [**] CMCC #[**]
"[**]"
By A. Atala, R. S. Langer and Joseph Vacanti

M.I.T. Case [**] CMCC #[**]
"[**]"
By A. Atala, R. S. Langer and Joseph Vacanti

MIT Case [**]
"[**]"
By R. Langer, A. Mikos, D. Ingber and J. Vacanti
U.S.S.N. [**]           Filed [**]
PCT S.N. PCT/US[**]     Filed [**]

MIT Case [**]
"[**]"
By A. Mikos, R. Langer
U.S.S.N. [**]           Filed [**]

M.I.T.  Case No. [**]
"[**]"
By A. Atala,
U.S.S.N. [**]           Filed [**]
U.S.S.N.  ________      Filed [**]


                                      -32-
<PAGE>

                                   APPENDIX B

      Foreign countries in which PATENT RIGHTS shall be filed, prosecuted and
maintained in accordance with Article 6:

Canada
Great Britain
France
Germany
Italy

                                      -33-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                  FIRST AMENDMENT TO RESTATED LICENSE AGREEMENT

      This Amendment is to the License Agreement dated July 1, 1996 between
M.I.T. and REPROGENESIS, INC. The parties thereto now further agree as follows:

      1.  M.I.T. acknowledges that Reprogenesis has used reasonable efforts to
          meet the milestone of paragraph 3.2(a) of the License Agreement, and
          although a LICENSED PRODUCT or LICENSED SERVICE will not be introduced
          by [**], M.I.T. will not use this fact to attempt termination of the
          License Agreement under paragraph 3.3.

      2.  Paragraph 3.2(a) of the License Agreement shall be amended to read:

                  3.2 (a) LICENSEE shall use best efforts to introduce the first
                  LICENSD PRODUCT or LICENSED SERVICE to commercial sale by
                  [**].

      Agreed to for:

MASSACHUSETTS INSTITUTE OF TECHNOLOGY       REPROGENESIS, INC.


By:  /s/ Lita Nelson                        By:  /s/ Daniel R. Omstead
     ---------------                             ---------------------

Name: Lita Nelston                          Name: Daniel R. Omstead

Title: Director Technology                  Title: President

Licensing Office

Date: June 9, 1999                          Date: 6/9/99


                                       -1-
<PAGE>

  Confidential materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                                SECOND AMENDMENT
                  TO THE AMENDED AND RESTATED LICENSE AGREEMENT

      This Second Amendment with the Effective Date of ________ is to the
Amended and Restated License Agreement dated July 1, 1996 between M.I.T. and
REPROGENESIS, INC. ("License Agreement").

      Pursuant to Paragraph 2.2 of the License Agreement, the parties thereto
further agree as follows:

      1. The inventions(s) disclosed and claimed in the following applications
      shall be added to the PATENT RIGHTS as defined in Paragraph 1.2 of the
      License Agreement:

            M.I.T. Case No. [**] (CMCC [**])
            "[**]"
            by Anthony Atala
            U.S. Provisional Application No. [**]
            Filed October 31, 1997
            PCT Application No. PCT/US[**]
            Filed [**]

      2. LICENSEE shall pay to M.I.T. a License Issue Fee of [**] ($[**]) for
      the above-identified rights.

      3. In addition to Paragraph 3.2 of the License Agreement, LICENSEE agrees
      to the following Due Diligence Milestones specific to the development of
      LICENSED PRODUCTS which fall under M.I.T. Case No. [**] (CMCC [**]):

          (a) LICENSEE shall file an IDE, IND, or equivalent on a LICENSED
              PRODUCT within [**] of the Effective Date of this Second
              Amendment.

          (b) LICENSEE shall maintain a clinical development program in
              accordance with industry standards for comparable products until
              market approval.

          (c) LICENSEE shall introduce a LICENSED PRODUCT in the bladder field
              to the market within [**] of the Effective Date of this Second
              Amendment.

      4. This Amendment is made as a part of the settlement of a disagreement
      concerning the proper scope of Paragraph 2.2 of the License Agreement and
      is not to be taken as either an admission of or denial by M.I.T. (for
      itself or on behalf of the Children's Medical Center Corporation) that
      CMCC Cases [**], and/or [**] are dominated by the claims of the M.I.T.
      Case No. [**] as originally filed.

      5. Any option rights LICENSEE may have under Paragraph 2.2 of the License
      Agreement to CMCC Cases [**],[**],[**], and [**] and Children's Hospital's
      right to license these cases shall be modified in accordance with the
      Agreements dated February 22, 2000, attached to this Second Amendment for
      reference purposes only.


                                       -1-
<PAGE>

      Agreed to for:

MASSACHUSETTS INSTITUTE OF
TECHNOLOGY                               REPROGENESIS, INC.


By: /s/_______________________________   By: /s/______________________________

Name: ________________________________   Name:________________________________

Title:________________________________   Title:_______________________________

Date: ________________________________   Date:________________________________


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