Document:

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                                  Exhibit 4.6

                                 MATRITECH, INC.

                                 1992 STOCK PLAN

                           (AS AMENDED JUNE 16, 2000)

     1.   PURPOSE. This Amended and Restated 1992 Stock Plan (the "Plan") is
intended to provide incentives: (a) to the officers and other employees of
Matritech, Inc. (the "Company"), its parent (if any) and any present or future
subsidiaries of the Company (collectively, "Related Corporations") by providing
them with opportunities to purchase stock in the Company pursuant to options
granted hereunder which qualify as "incentive stock options" under Section
422(b) of the Internal Revenue Code of 1986, as amended (the "Code") ("ISO" or
"ISOs"); (b) to directors, officers, employees and consultants of the Company
and Related Corporations by providing them with opportunities to purchase stock
in the Company pursuant to options granted hereunder which do not qualify as
ISOs ("Non-Qualified Option" or "Non-Qualified Options"); (c) to directors,
officers, employees and consultants of the Company and Related Corporations by
providing them with awards of stock in the Company ("Awards"); and (d) to
directors, officers, employees and consultants of the Company and Related
Corporations by providing them with opportunities to make direct purchases of
stock in the Company ("Purchases"). Both ISOs and Non-Qualified Options are
referred to hereafter individually as an "Option" and collectively as "Options".
Options, Awards and authorizations to make Purchases are referred to hereafter
collectively as "Stock Rights". As used herein, the terms "parent" and
"subsidiary" mean "parent corporation" and "subsidiary corporation",
respectively, as those terms are defined in Section 424 of the Code.

     2.   ADMINISTRATION OF THE PLAN.

          A.   BOARD OR COMMITTEE ADMINISTRATION. The Plan shall be administered
     by the Board of Directors of the Company (the "Board") or by a committee
     appointed by the Board (the "Committee"), comprised of, to the extent
     required by applicable regulations under Section 162(m) of the Code, two or
     more outside directors as defined in applicable regulations thereunder and
     to the extent required by Rule 16b-3 promulgated under the Securities
     Exchange Act of 1934 or any successor provision ("Rule 16b-3"),
     disinterested administrators. Hereinafter, all references in this Plan to
     the "Committee" shall mean the Board if no Committee has been appointed.
     Subject to ratification of the grant or authorization of each Stock Right
     by the Board (if so required by applicable state law), and subject to the
     terms of the Plan, the Committee shall have the authority to (i) determine
     the employees of the Company and Related Corporations (from among the class
     of employees eligible under paragraph 3 to receive ISOs) to whom ISOs may
     be granted, and to determine (from among the class of individuals and
     entities eligible

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     under paragraph 3 to receive Non-Qualified Options and Awards and to make
     Purchases) to whom Non-Qualified Options, Awards and authorizations to make
     Purchases may be granted; (ii) determine the time or times at which Options
     or Awards may be granted or Purchases made; (iii) determine the option
     price of shares subject to each Option, which price shall not be less than
     the minimum price specified in paragraph 6, and the purchase price of
     shares subject to each Purchase; (iv) determine whether each Option granted
     shall be an ISO or a Non-Qualified Option; (v) determine (subject to
     paragraph 7) the time or times when each Option shall become exercisable
     and the duration of the exercise period; (vi) determine whether
     restrictions such as repurchase options are to be imposed on shares subject
     to Options, Awards and Purchases and the nature of such restrictions, if
     any, and (vii) interpret the Plan and prescribe and rescind rules and
     regulations relating to it. If the Committee determines to issue a
     Non-Qualified Option, it shall take whatever actions it deems necessary,
     under Section 422 of the Code and the regulations promulgated thereunder,
     to ensure that such Option is not treated as an ISO. The interpretation and
     construction by the Committee of any provisions of the Plan or of any Stock
     Right granted under it shall be final unless otherwise determined by the
     Board. The Committee may from time to time adopt such rules and regulations
     for carrying out the Plan as it may deem best. No member of the Board or
     the Committee shall be liable for any action or determination made in good
     faith with respect to the Plan or any Stock Right granted under it.

          B.   COMMITTEE ACTIONS. The Committee may select one of its members as
     its chairman, and shall hold meetings at such times and places as it may
     determine. Acts by a majority of the Committee, or acts reduced to or
     approved in writing by a majority of the members of the Committee (if
     consistent with applicable state law), shall be the valid acts of the
     Committee. From time to time the Board may increase the size of the
     Committee and appoint additional members thereof, remove members (with or
     without cause) and appoint new members in substitution therefor, fill
     vacancies however caused, or remove all members of the Committee and
     thereafter directly administer the Plan.

          C.   GRANT OF STOCK RIGHTS TO BOARD MEMBERS. Stock Rights may be
     granted to members of the Board consistent with the provisions of the first
     sentence of paragraph 2(A) above, if applicable. All grants of Stock Rights
     to members of the Board shall in all other respects be made in accordance
     with the provisions of this Plan applicable to other eligible persons.
     Consistent with the provisions of the first sentence of paragraph 2(A)
     above, members of the Board who are either (i) eligible for Stock Rights
     pursuant to the Plan or (ii) have been granted Stock Rights may vote on any
     matters affecting the administration of the Plan or the grant of any Stock
     Rights pursuant to the Plan, except that no such member shall act upon the
     granting to himself of Stock Rights, but any such member may be counted in
     determining the existence of a quorum at any meeting of the Board during
     which action is taken with respect to the granting to him of Stock Rights.

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     3.   ELIGIBLE EMPLOYEES AND OTHERS. ISOs may be granted to any employee of
the Company or any Related Corporation. Those officers and directors of the
Company who are not employees may not be granted ISOs under the Plan.
Non-Qualified Options, Awards and authorizations to make Purchases may be
granted to any employee, officer or director (whether or not also an employee)
or consultant of the Company or any Related Corporation. The Committee may take
into consideration a recipient's individual circumstances in determining whether
to grant an ISO, a Non-Qualified Option, an Award or an authorization to make a
Purchase. Granting of any Stock Right to any individual or entity shall neither
entitle that individual or entity to, nor disqualify him from, participation in
any other grant of Stock Rights.

     4.   STOCK. The stock subject to Options, Awards and Purchases shall be
authorized but unissued shares of Common Stock of the Company, par value $.01
per share (the "Common Stock"), or shares of Common Stock reacquired by the
Company in any manner. The aggregate number of shares which may be issued
pursuant to the Plan is 2,500,000, subject to adjustment as provided in
paragraph 13; PROVIDED, HOWEVER, that such number of shares shall not be subject
to adjustment by reason of the 9.1 for one stock split in the form of a stock
dividend declared by the Board of Directors of the Company at a meeting on March
2, 1992. Any such shares may be issued as ISOs, Non-Qualified Options or Awards,
or to persons or entities making Purchases, so long as the number of shares so
issued does not exceed such number, as adjusted. If any Stock Right granted
under the Plan shall expire or terminate for any reason without having been
exercised in full or shall cease for any reason to be exercisable in whole or in
part, the unissued shares subject to such Stock Options shall again be available
for grants of Stock Rights under the Plan. For the purposes of the foregoing
sentence, shares withheld from the Stock Right exercise to pay the exercise
price and/or tax consequences of the exercise shall be deemed to have been
issued.

     No employee, officer, director or consultant of the Company or any Related
Corporation may be issued, in the aggregate, more than 500,000 shares of Common
Stock under the Plan. If any Option granted under the Plan shall expire or
terminate for any reason without having been exercised in full or shall cease
for any reason to be exercisable in whole or in part, the unpurchased shares
subject to such Option shall be included in the determination of the aggregate
number of shares of Common Stock deemed to have been granted to such employee
under the Plan.

     5.   GRANTING OF STOCK RIGHTS. Stock Rights may be granted under the Plan
at any time after the effective date of the Company's initial public offering,
and prior to March 2, 2002. The date of grant of a Stock Right under the Plan
will be the date specified by the Committee at the time it grants the Stock
Right; provided, however, that such date shall not be prior to the date on which
the Committee acts to approve the grant. The Committee shall have the right,
with the consent of the optionee, to convert an ISO granted under the Plan to a
Non-Qualified Option pursuant to paragraph 16.

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     6.   MINIMUM OPTION PRICE; ISO LIMITATIONS.

          A.   PRICE FOR NON-QUALIFIED OPTIONS, AWARDS AND PURCHASES. The
     exercise price per share specified in the agreement relating to each
     Non-Qualified Option granted, and the purchase price per share of stock
     granted in any Award or authorized as a Purchase, under the Plan shall in
     no event be less than the minimum legal consideration required therefor
     under the laws of Delaware or the laws of any jurisdiction in which the
     Company or its successors in interest may be organized.

          B.   PRICE FOR ISOS. The exercise price per share specified in the
     agreement relating to each ISO granted under the Plan shall not be less
     than the fair market value per share of Common Stock on the date of such
     grant. In the case of an ISO to be granted to an employee owning stock
     possessing more than ten percent (10%) of the total combined voting power
     of all classes of stock of the Company or any Related Corporation, the
     price per share specified in the agreement relating to such ISO shall not
     be less than one hundred ten percent (110%) of the fair market value per
     share of Common Stock on the date of grant.

          C.   $100,000 ANNUAL LIMITATION ON ISOS. Each eligible employee may be
     granted ISOs only to the extent that, in the aggregate under this Plan and
     all incentive stock option plans of the Company and any Related
     Corporation, such ISOs do not become exercisable for the first time by such
     employee during any calendar year in a manner which would entitle the
     employee to purchase more than $100,000 in fair market value (determined at
     the time the ISOs were granted) of Common Stock in that year. Any options
     granted to an employee in excess of such amount will be granted as
     Non-Qualified Options.

          D.   DETERMINATION OF FAIR MARKET VALUE. If, at the time an Option is
     granted under the Plan, the Company's Common Stock is publicly traded,
     "fair market value" shall be determined as of the last business day for
     which the prices or quotes discussed in this sentence are available prior
     to the date such Option is granted and shall mean (i) the average (on that
     date) of the high and low prices of the Common Stock on the principal
     national securities exchange on which the Common Stock is traded, if the
     Common Stock is then traded on a national securities exchange; or (ii) the
     last reported sale price (on that date) of the Common Stock on the NASDAQ
     National Market List, if the Common Stock is not then traded on a national
     securities exchange; or (iii) the closing bid price (or average of bid
     prices) last quoted (on that date) by an established quotation service for
     over-the-counter securities, if the Common Stock is not reported on the
     NASDAQ National Market List. However, if the Common Stock is not publicly
     traded at the time an Option is granted under the Plan, "fair market value"
     shall be deemed to be the fair value of the Common Stock as determined by
     the Committee after taking into consideration all factors which it deems
     appropriate, including, without limitation, recent sale and offer prices of
     the Common Stock in private transactions negotiated at arm's length.

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     7.   OPTION DURATION. Subject to earlier termination as provided in
paragraphs 9 and 10, each Option shall expire on the date specified by the
Committee, but not more than (i) ten years and one day from the date of grant in
the case of Non-Qualified Options, (ii) ten years from the date of grant in the
case of ISOs generally, and (iii) five years from the date of grant in the case
of ISOs granted to an employee owning stock possessing more than ten percent
(10%) of the total combined voting power of all classes of stock of the Company
or any Related Corporation. Subject to earlier termination as provided in
paragraphs 9 and 10, the term of each ISO shall be the term set forth in the
original instrument granting such ISO, except with respect to any part of such
ISO that is converted into a Non-Qualified Option pursuant to paragraph 16.

     8.   EXERCISE OF OPTION. Subject to the provisions of paragraphs 9 through
12, each Option granted under the Plan shall be exercisable as follows:

          A.   VESTING. The Option shall either be fully exercisable on the date
     of grant or shall become exercisable thereafter in such installments as the
     Committee may specify.

          B.   FULL VESTING OF INSTALLMENTS. Once an installment becomes
     exercisable it shall remain exercisable until expiration or termination of
     the Option, unless otherwise specified by the Committee.

          C.   PARTIAL EXERCISE. Each Option or installment may be exercised at
     any time or from time to time, in whole or in part, for up to the total
     number of shares with respect to which it is then exercisable.

          D.   ACCELERATION OF VESTING. The Committee shall have the right to
     accelerate the date of exercise of any installment of any Option; provided
     that the Committee shall not, without the consent of an optionee,
     accelerate the exercise date of any installment of any Option granted to
     any employee as an ISO (and not previously converted into a Non-Qualified
     Option pursuant to paragraph 16) if such acceleration would violate the
     annual vesting limitation contained in Section 422(d) of the Code, as
     described in paragraph 6(C).

     9.   TERMINATION OF EMPLOYMENT. If an ISO optionee ceases to be employed by
the Company and all Related Corporations other than by reason of death or
disability as defined in paragraph 10, no further installments of his ISOs shall
become exercisable, and his ISOs shall terminate after the passage of ninety
(90) days from the date of termination of his employment, but in no event later
than on their specified expiration dates, except to the extent that such ISOs
(or unexercised installments thereof) have been converted into Non-Qualified
Options pursuant to paragraph 16. Employment shall be considered as continuing
uninterrupted during any bona fide leave of absence (such as those attributable
to illness, military obligations or governmental service) provided that the
period of such leave does not exceed 90 days or, if longer, any period during
which such optionee's right to reemployment is guaranteed by statute. A bona
fide leave of absence with the written

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approval of the Committee shall not be considered an interruption of employment
under the Plan, provided that such written approval contractually obligates the
Company or any Related Corporation to continue the employment of the optionee
after the approved period of absence. ISOs granted under the Plan shall not be
affected by any change of employment within or among the Company and Related
Corporations, so long as the optionee continues to be an employee of the Company
or any Related Corporation. Nothing in the Plan shall be deemed to give any
grantee of any Stock Right the right to be retained in employment or other
service by the Company or any Related Corporation for any period of time.

     10.  DEATH; DISABILITY.

          A.   DEATH. If an ISO optionee ceases to be employed by the Company
     and all Related Corporations by reason of his death, any ISO of his may be
     exercised, to the extent of the number of shares with respect to which he
     could have exercised it on the date of his death, by his estate, personal
     representative or beneficiary who has acquired the ISO by will or by the
     laws of descent and distribution, at any time prior to the earlier of the
     specified expiration date of the ISO or 180 days from the date of the
     optionee's death.

          B.   DISABILITY. If an ISO optionee ceases to be employed by the
     Company and all Related Corporations by reason of his disability, he shall
     have the right to exercise any ISO held by him on the date of termination
     of employment, to the extent of the number of shares with respect to which
     he could have exercised it on that date, at any time prior to the earlier
     of the specified expiration date of the ISO or 180 days from the date of
     the termination of the optionee's employment. For the purposes of the Plan,
     the term "disability" shall mean "permanent and total disability" as
     defined in Section 22(e)(3) of the Code or successor statute.

     11.  ASSIGNABILITY. No Option shall be assignable or transferable by the
optionee except by will or by the laws of descent and distribution. During the
lifetime of the optionee each Option shall be exercisable only by him.

     12.  TERMS AND CONDITIONS OF OPTIONS. Options shall be evidenced by
instruments (which need not be identical) in such forms as the Committee may
from time to time approve. Such instruments shall conform to the terms and
conditions set forth in paragraphs 6 through 11 hereof and may contain such
other provisions as the Committee deems advisable which are not inconsistent
with the Plan, including restrictions applicable to shares of Common Stock
issuable upon exercise of Options. In granting any Non-Qualified Option, the
Committee may specify that such Non-Qualified Option shall be subject to the
restrictions set forth herein with respect to ISOs, or to such other termination
and cancellation provisions as the Committee may determine. The Committee may
from time to time confer authority and responsibility on one or more of its own
members and/or one or more officers of the Company to execute and deliver such
instruments. The proper officers of the Company are authorized and directed to
take any

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and all action necessary or advisable from time to time to carry out the terms
of such instruments.

     13.  ADJUSTMENTS. Upon the occurrence of any of the following events, an
optionee's rights with respect to Options granted to him hereunder shall be
adjusted as hereinafter provided, unless otherwise specifically provided in the
written agreement between the optionee and the Company relating to such Option:

          A.   STOCK DIVIDENDS AND STOCK SPLITS. If the shares of Common Stock
     shall be subdivided or combined into a greater or smaller number of shares
     or if the Company shall issue any shares of Common Stock as a stock
     dividend on its outstanding Common Stock, the number of shares of Common
     Stock deliverable upon the exercise of Options shall be appropriately
     increased or decreased proportionately, and appropriate adjustments shall
     be made in the purchase price per share to reflect such subdivision,
     combination or stock dividend.

          B.   CONSOLIDATIONS OR MERGERS. If the Company is to be consolidated
     with or acquired by another entity in a merger, sale of all or
     substantially all of the Company's assets or otherwise (an "Acquisition"),
     the Committee or the board of directors of any entity assuming the
     obligations of the Company hereunder (the "Successor Board"), shall, as to
     outstanding Options, either (i) make appropriate provision for the
     continuation of such Options by substituting on an equitable basis for the
     shares then subject to such Options the consideration payable with respect
     to the outstanding shares of Common Stock in connection with the
     Acquisition; or (ii) upon written notice to the optionees, provide that all
     Options must be exercised, to the extent then exercisable, within a
     specified number of days of the date of such notice, at the end of which
     period the Options shall terminate; or (iii) terminate all Options in
     exchange for a cash payment equal to the excess of the fair market value of
     the shares subject to such Options (to the extent then exercisable) over
     the exercise price thereof.

          C.   RECAPITALIZATION OR REORGANIZATION. In the event of a
     recapitalization or reorganization of the Company (other than a transaction
     described in subparagraph B above) pursuant to which securities of the
     Company or of another corporation are issued with respect to the
     outstanding shares of Common Stock, an optionee upon exercising an Option
     shall be entitled to receive for the purchase price paid upon such exercise
     the securities he would have received if he had exercised his Option prior
     to such recapitalization or reorganization.

          D.   MODIFICATION OF ISOS. Notwithstanding the foregoing, any
     adjustments made pursuant to subparagraphs A, B or C with respect to ISOs
     shall be made only after the Committee, after consulting with counsel for
     the Company, determines whether such adjustments would constitute a
     "modification" of such ISOs (as that term is defined in Section 424 of the
     Code) or would cause any adverse tax consequences for the holders of such
     ISOs. If the Committee determines that such

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     adjustments made with respect to ISOs would constitute a modification of
     such ISOs, it may refrain from making such adjustments.

          E.   DISSOLUTION OR LIQUIDATION. In the event of the proposed
     dissolution or liquidation of the Company, each Option will terminate
     immediately prior to the consummation of such proposed action or at such
     other time and subject to such other conditions as shall be determined by
     the Committee.

          F.   ISSUANCES OF SECURITIES. Except as expressly provided herein, no
     issuance by the Company of shares of stock of any class, or securities
     convertible into shares of stock of any class, shall affect, and no
     adjustment by reason thereof shall be made with respect to, the number or
     price of shares subject to Options. No adjustments shall be made for
     dividends paid in cash or in property other than securities of the Company.

          G.   FRACTIONAL SHARES. No fractional shares shall be issued under the
     Plan and the optionee shall receive from the Company cash in lieu of such
     fractional shares.

          H.   ADJUSTMENTS. Upon the happening of any of the events described in
     subparagraphs A, B or C above, the class and aggregate number of shares set
     forth in paragraph 4 hereof that are subject to Stock Rights which
     previously have been or subsequently may be granted under the Plan shall
     also be appropriately adjusted to reflect the events described in such
     subparagraphs. The Committee or the Successor Board shall determine the
     specific adjustments to be made under this paragraph 13 and, subject to
     paragraph 2, its determination shall be conclusive.

     If any person or entity owning restricted Common Stock obtained by exercise
of a Stock Right made hereunder receives shares or securities or cash in
connection with a corporate transaction described in subparagraphs A, B or C
above as a result of owning such restricted Common Stock, such shares or
securities or cash shall be subject to all of the conditions and restrictions
applicable to the restricted Common Stock with respect to which such shares or
securities or cash were issued, unless otherwise determined by the Committee or
the Successor Board.

     14.  MEANS OF EXERCISING STOCK RIGHTS. A Stock Right (or any part or
installment thereof) shall be exercised by giving written notice to the Company
at its principal office address. Such notice shall identify the Stock Right
being exercised and specify the number of shares as to which such Stock Right is
being exercised, accompanied by full payment of the purchase price therefor (a)
in United States dollars in cash or by check, (b) at the discretion of the
Committee, through delivery or withholding from the Stock Right exercise of
shares of Common Stock having a fair market value equal as of the date of the
exercise to the cash exercise price of the Stock Right, (c) at the discretion of
the Committee, by delivery of the grantee's personal recourse note bearing
interest payable not less than annually at no less than 100% of the lowest
applicable Federal rate, as

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defined in Section 1274(d) of the Code, (d) at the discretion of the Committee
and consistent with applicable law, through the delivery of an assignment to the
Company of a sufficient amount of the proceeds from the sale of the Common Stock
acquired upon exercise of the Stock Right and an authorization to the broker or
selling agent to pay that amount to the Company, which sale shall be at the
participant's direction at the time of exercise, or (e) at the discretion of the
Committee, by any combination of (a), (b), (c) and (d) above. If the Committee
exercises its discretion to permit payment of the exercise price of an ISO by
means of the methods set forth in clauses (b), (c), (d) or (e) of the preceding
sentence, such discretion shall be exercised in writing at the time of the grant
of the ISO in question. The holder of a Stock Right shall not have the rights of
a shareholder with respect to the shares covered by his Stock Right until the
date of issuance of a stock certificate to him for such shares. Except as
expressly provided above in paragraph 13 with respect to changes in
capitalization and stock dividends, no adjustment shall be made for dividends or
similar rights for which the record date is before the date such stock
certificate is issued.

     15.  TERM AND AMENDMENT OF PLAN. This Plan was adopted by the Board of
Directors and Stockholders of the Company on March 2, 1992. The Plan shall
expire at the end of the day on March 2, 2002 (except as to Options outstanding
on that date). The Board may terminate or amend the Plan in any respect at any
time, except that, without the approval of the stockholders obtained within 12
months before or after the Board adopts a resolution authorizing any of the
following actions: (a) the total number of shares that may be issued under the
Plan may not be increased materially (except by adjustment pursuant to paragraph
13); (b) the benefits accruing to participants under the Plan may not be
materially increased; (c) the requirements as to eligibility for participation
in the Plan may not be materially modified; (d) the provisions of paragraph 3
regarding eligibility for grants of ISOs may not be modified; (e) the provisions
of paragraph 6(B) regarding the exercise price at which shares may be offered
pursuant to ISOs may not be modified (except by adjustment pursuant to paragraph
13); (f) the expiration date of the Plan may not be extended; and (g) the Board
may not take any action which would cause the Plan to fail to comply with Rule
16b-3. Except as otherwise provided in this paragraph 15, in no event may action
of the Board or stockholders alter or impair the rights of a grantee, without
his consent, under any Stock Right previously granted to him.

     16.  CONVERSION OF ISOS INTO NON-QUALIFIED OPTIONS; TERMINATION OF ISOS.
The Committee, at the written request of any optionee, may in its discretion
take such actions as may be necessary to convert such optionee's ISOs (or any
installments or portions of installments thereof) that have not been exercised
on the date of conversion into Non-Qualified Options at any time prior to the
expiration of such ISOs, regardless of whether the optionee is an employee of
the Company or a Related Corporation at the time of such conversion. Such
actions may include, but not be limited to, extending the exercise period or
reducing the exercise price of the appropriate installments of such ISOs. At the
time of such conversion, the Committee (with the consent of the optionee) may
impose such conditions on the exercise of the resulting Non-Qualified Options as
the

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Committee in its discretion may determine, provided that such conditions shall
not be inconsistent with this Plan. Nothing in the Plan shall be deemed to give
any optionee the right to have such optionee's ISOs converted into Non-Qualified
Options, and no such conversion shall occur until and unless the Committee takes
appropriate action. The Committee, with the consent of the optionee, may also
terminate any portion of any ISO that has not been exercised at the time of such
termination.

     17.  APPLICATION OF FUNDS. The proceeds received by the Company from the
sale of shares pursuant to Options granted and Purchases authorized under the
Plan shall be used for general corporate purposes.

     18.  GOVERNMENTAL REGULATION. The Company's obligation to sell and deliver
shares of the Common Stock under this Plan is subject to the approval of any
governmental authority required in connection with the authorization, issuance
or sale of such shares.

     19.  WITHHOLDING OF ADDITIONAL INCOME TAXES. Upon the exercise of a
Non-Qualified Option, the grant of an Award, the making of a Purchase of Common
Stock for less than its fair market value, the making of a Disqualifying
Disposition (as defined in paragraph 20) or the vesting of restricted Common
Stock acquired on the exercise of a Stock Right hereunder, the Company, in
accordance with Section 3402(a) of the Code, may require the optionee, Award
recipient or purchaser to pay additional withholding taxes in respect of the
amount that is considered compensation includible in such person's gross income.
The Committee in its discretion may condition (i) the exercise of an Option,
(ii) the grant of an Award, (iii) the making of a Purchase of Common Stock for
less than its fair market value, or (iv) the vesting of restricted Common Stock
acquired by exercising a Stock Right, on the grantee's payment of such
additional withholding taxes. Payment of such additional withholding taxes shall
be in United States dollars in cash or by check and/or at the discretion of the
Committee, through the delivery of previously held shares of common stock or
withholding from the Stock Right exercise of shares of Common Stock having a
fair market value equal as of the date of exercise to the amount of such
withholding taxes.

     20.  NOTICE TO COMPANY OF DISQUALIFYING DISPOSITION. Each employee who
receives an ISO must agree to notify the Company in writing immediately after
the employee makes a Disqualifying Disposition of any Common Stock acquired
pursuant to the exercise of an ISO. A Disqualifying Disposition is any
disposition (including any sale) of such Common Stock before the later of (a)
two years after the date the employee was granted the ISO, or (b) one year after
the date the employee acquired Common Stock by exercising the ISO. If the
employee has died before such stock is sold, these holding period requirements
do not apply and no Disqualifying Disposition can occur thereafter.

     21.  GOVERNING LAW; CONSTRUCTION. The validity and construction of the Plan
and the instruments evidencing Stock Rights shall be governed by the laws of the
State of Delaware, or the laws of any jurisdiction in which the Company or its
successors in

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interest may be organized. In construing this Plan, the singular shall include
the plural and the masculine gender shall include the feminine and neuter,
unless the context otherwise requires.

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                  REGISTER OF AMENDMENTS TO THE 1992 STOCK PLAN

MAY 13, 1994 AT THE ANNUAL MEETING OF STOCKHOLDERS:

a.   Section 4 was amended to increase the number of authorized shares from
     260,000 to 625,000 shares.

b.   Certain provisions were amended to qualify grants under this plan as
     performance based compensation under Section 162(m) of the Internal Revenue
     Code of 1986, as amended.

JUNE 7, 1996 AT THE ANNUAL MEETING OF STOCKHOLDERS

a.   Section 4 was amended to increase the number of authorized shares from
     625,000 to 1,000,000 shares.

JUNE 13, 1997 AT THE ANNUAL MEETING OF STOCKHOLDERS

a.   Section 4 was amended to increase the number of authorized shares from
     1,000,000 to 1,500,000.

b.   Section 4 was amended to increase the limitation on the maximum aggregate
     number of shares that may be issued under the Plan to any one person from
     300,000 to 500,000 shares.

JUNE 16, 2000 AT THE ANNUAL MEETING OF STOCKHOLDERS

a.   Section 4 was amended to increase the number of authorized shares from
     1,500,000 to 2,500,000.<PAGE>   1
                                  Exhibit 4.7

                                 MATRITECH, INC.

                              AMENDED AND RESTATED
                  1992 NON-EMPLOYEE DIRECTOR STOCK OPTION PLAN

                           (as amended June 16, 2000)

     1.   PURPOSE. This Non-Qualified Stock Option Plan, to be known as the 1992
Non-Employee Director Stock Option Plan (hereinafter, this "Plan") is intended
to promote the interests of Matritech, Inc. (hereinafter, the "Company") by
providing an inducement to obtain and retain the services of qualified persons
who are not employees or officers of the Company to serve as members of its
Board of Directors (the "Board").

     2.   AVAILABLE SHARES. The total number of shares of Common Stock, par
value $.01 per share, of the Company (the "Common Stock"), for which options may
be granted under this Plan shall not exceed 465,000 shares, subject to
adjustment in accordance with paragraph 10 of this Plan; provided, however, that
such number of shares shall not be subject to adjustment by reason of the 9.1
for one stock split in the form of a stock dividend declared by the Board of
Directors of the Company at a meeting on March 2, 1992. Shares subject to this
Plan are authorized but unissued shares or shares that were once issued and
subsequently reacquired by the Company. If any options granted under this Plan
are surrendered before exercise or lapse without exercise (and without being
used to pay the exercise price or tax withholding), in whole or in part, the
shares reserved therefor shall continue to be available under this Plan.

     3.   ADMINISTRATION. This Plan shall be administered by the Board or by a
committee appointed by the Board (the "Committee"). In the event the Board fails
to appoint or refrains from appointing a Committee, the Board shall have all
power and authority to administer this Plan. In such event, the word "Committee"
wherever used herein shall be deemed to mean the Board. The Committee shall,
subject to the provisions of the Plan, have the power to construe this Plan, to
determine all questions hereunder, and to adopt and amend such rules and
regulations for the administration of this Plan as it may deem desirable. No
member of the Board or the Committee shall be liable for any action or
determination made in good faith with respect to this Plan or any option granted
under it.

     4.   AUTOMATIC GRANT OF OPTIONS. Subject to the availability of shares
under this Plan, (a) each person who is first elected as a member of the Board
after the closing of the Company's initial public offering and during the term
of this Plan and who is not an employee or officer of the Company on the date of
such election shall be automatically granted an option (an "Initial Option") to
purchase 10,000 shares of Common Stock; (b) starting with the 1996 Annual
Meeting of Stockholders, each person who is elected or re-elected as a member of
the Board at the Company's Annual Meeting of Stockholders in a given year (the
"Annual Meeting") and who is not an employee or officer of the Company shall be
automatically granted as of the date of such Annual Meeting, an option (an
"Annual Option") to purchase 10,000 shares of Common Stock; and (c) any
individual who is first elected to the Board after the Annual Meeting of
Stockholders and who is not an employee or officer of the Company on the date of
such election shall automatically receive, in addition to the Initial Option, a
fraction of the Annual Option

<PAGE>   2

                                       -2-

(rounded to the nearest whole share) equal to (x) divided by twelve (12), where
(x) equals the number of complete months remaining until the first anniversary
of the preceding Annual Meeting of Stockholders. The options to be granted under
this paragraph 4 shall be the only options ever to be granted at any time to
such member under this Plan. Except for the specific options referred to above,
no other options shall be granted under this Plan.

     5.   OPTION PRICE AND FAIR MARKET VALUE. The purchase price of the stock
covered by an option granted pursuant to this Plan shall be 100% of the fair
market value of such shares on the day the option is granted. The option price
will be subject to adjustment in accordance with the provisions of paragraph 10
of this Plan. For purposes of this Plan, if, at the time an option is granted
under the Plan, the Company's Common Stock is publicly traded, "fair market
value" shall be determined as of the last business day for which the prices or
quotes discussed in this sentence are available prior to the date such option is
granted and shall mean (i) the average (on that date) of the high and low prices
of the Common Stock on the principal national securities exchange on which the
Common Stock is traded, if the Common Stock is then traded on a national
securities exchange; or (ii) the last reported sale price (on that date) of the
Common Stock on the Nasdaq National Market, if the Common Stock is not then
traded on a national securities exchange; or (iii) the closing bid price (or
average of bid prices) last quoted (on that date) by an established quotation
service for over-the-counter securities, if the Common Stock is not reported on
the Nasdaq National Market.

     6.   PERIOD OF OPTION. Unless sooner terminated in accordance with the
provisions of paragraph 8 of this Plan, an option granted hereunder shall expire
on the date which is ten (10) years after the date of grant of the option.

     7.   VESTING OF SHARES AND NON-TRANSFERABILITY OF OPTIONS.

          (a)  VESTING. Options granted under this Plan shall not be exercisable
until they become vested.

               (i)  Initial Options granted under Paragraph 4(a) of this Plan
shall vest in the optionee, and thus become exercisable, in accordance with the
following schedule so that 100% of each Initial Option shall become exercisable
four years from the date of grant, provided that the optionee has continuously
served as a member of the Board through such vesting date:

<PAGE>   3

                                       -3-

<TABLE>
<CAPTION>
   Percentage of Option Which
   Will Become Exercisable            Date of Vesting
   --------------------------         ---------------

<S>                                   <C>
           0                          Less than one year from the date of grant

           25%                        One year from the date of grant

           25%                        Two years from the date of grant

           25%                        Three years from the date of grant

           25%                        Four years from the date of grant
</TABLE>

               (ii) Annual Options granted under Paragraph 4(b) of this Plan
shall vest in the optionee, and thus become exercisable, in accordance with the
following schedule so that 100% of each Annual Grant shall become exercisable on
the first anniversary of the Annual Meeting for which they were granted,
provided that the optionee has continuously served as a member of the Board
through such vesting date:

<TABLE>
<CAPTION>
  Number of Option Shares Which
      Will Become Exercisable         Date of Vesting
  -----------------------------       ---------------

<S>                                    <C>
           0                           Less than three months from the date of the Annual
                                       Meeting for which they were granted

           2,500                       Three months from the date of the Annual Meeting for
                                       which they were granted

           2,500                       Six months from the date of the Annual Meeting for
                                       which they were granted

           2,500                       Nine months from the date of the Annual Meeting for
                                       which they were granted

           2,500                       Twelve months from the date of the Annual Meeting for
                                       which they were granted
</TABLE>

               (iii) Annual Options granted pursuant to Paragraph 4(c) shall
vest on the same dates as Annual Options granted pursuant to Paragraph 4(b), but
only to the extent that such dates are after the date of election to the Board
of Directors. The number of shares which will vest on each such date will be
2,500, except that the number of shares which will vest at the first vesting
date following the date of election may be less than 2,500 and shall equal only
the balance of such Annual Options granted which will not vest on later dates.
Annual Options granted pursuant to Paragraph 4(c) shall vest only if the
optionee has continuously served the Board

<PAGE>   4

                                      -4-

through such vesting date. By way of example, if a director is elected on a date
that is more than ten, but less than eleven months prior to the first
anniversary of the preceding Annual Meeting, such director shall receive an
Annual Option pursuant to Paragraph 4(c) equal to 8,333 shares [10,000 x
(10/12)] that shall become exercisable: 833 shares three months after the date
of the prior Annual Meeting, 2,500 shares six months after the date of the prior
Annual Meeting, 2,500 shares nine months after the date of the prior Annual
Meeting, and 2,500 shares twelve months after the date of the prior Annual
Meeting.

               (iv) The number of shares as to which options may be exercised
shall be cumulative, so that once the option shall become exercisable as to any
shares it shall continue to be exercisable as to said shares, until expiration
or termination of the option as provided in this Plan.

          (b)  LEGEND ON CERTIFICATES. The certificates representing such shares
shall carry such appropriate legend, and such written instructions shall be
given to the Company's transfer agent, as may be deemed necessary or advisable
by counsel to the Company in order to comply with the requirements of the
Securities Act of 1933 or any state securities laws.

          (c)  NON-TRANSFERABILITY. Any option granted pursuant to this Plan
shall not be assignable or transferable other than by will or the laws of
descent and distribution and shall be exercisable during the optionee's lifetime
only by him or her.

     8.   TERMINATION OF OPTION RIGHTS.

          (a)  In the event an optionee ceases to be a member of the Board for
any reason other than death or permanent disability, any then unexercised
portion of options granted to such optionee shall, to the extent not then
vested, immediately terminate and become void; any portion of an option which is
then vested but has not been exercised at the time the optionee so ceases to be
a member of the Board may be exercised, to the extent it is then vested, by the
optionee within 90 days of the date the optionee ceased to be a member of the
Board; and all options shall terminate after such 90 days have expired.

          (b)  In the event that an optionee ceases to be a member of the Board
by reason of his or her death or permanent disability, any option granted to
such optionee shall be immediately and automatically accelerated and become
fully vested and all unexercised options shall be exercisable by the optionee
(or by the optionee's personal representative, heir or legatee, in the event of
death) until the scheduled expiration date of the option.

     9.   EXERCISE OF OPTION AND RESALE RESTRICTIONS.

          (a)  EXERCISE OF OPTIONS. Subject to the terms and conditions of this
Plan and the option agreements, an option granted hereunder shall, to the extent
then exercisable, be exercisable in whole or in part by giving written notice to
the Company by mail or in person addressed to Matritech, Inc., 330 Nevada
Street, Newton, Massachusetts 02160, at its principal executive offices, stating
the number of shares with respect to which the option is being exercised,
accompanied by payment in full for such shares, which payment may be (a) in
whole

<PAGE>   5

                                      -5-

or in part in shares of the Common Stock of the Company already owned by the
person or persons exercising the option or shares subject to the option being
exercised (subject to such restrictions and guidelines as the Board may adopt
from time to time), valued at fair market value determined in accordance with
the provisions of paragraph 5 or (b) at the discretion of the Committee, and
consistent with applicable law, through the delivery of an assignment to the
Company of a sufficient amount of the proceeds from the sale of the Common Stock
acquired upon exercise of the option and an authorization to the broker or
selling agent to pay that amount to the Company, which sale shall be at the
participant's direction at the time of exercise; provided, however, that there
shall be no such exercise at any one time as to fewer than one hundred (100)
shares or all of the remaining shares then purchasable by the person or persons
exercising the option, if fewer than one hundred (100) shares. The Company's
transfer agent shall, on behalf of the Company, prepare a certificate or
certificates representing such shares acquired pursuant to exercise of the
option, shall register the optionee as the owner of such shares on the books of
the Company and shall cause the fully executed certificate(s) representing such
shares to be delivered to the optionee as soon as practicable after payment of
the option price in full. The holder of an option shall not have any rights of a
stockholder with respect to the shares covered by the option, except to the
extent that one or more certificates for such shares shall be delivered to him
or her upon the due exercise of the option.

          (b)  RESALE RESTRICTIONS. Under no circumstances may shares acquired
pursuant to the exercise of options hereunder be disposed of on or prior to the
date that is six months after the date such options were granted.

     10.  ADJUSTMENTS UPON CHANGES IN CAPITALIZATION AND OTHER MATTERS. Upon the
occurrence of any of the following events, an optionee's rights with respect to
options granted to him or her hereunder shall be adjusted as hereinafter
provided:

          (a)  STOCK DIVIDENDS AND STOCK SPLITS. If the shares of Common Stock
shall be subdivided or combined into a greater or smaller number of shares or if
the Company shall issue any shares of Common Stock as a stock dividend on its
outstanding Common Stock, the number of shares of Common Stock deliverable upon
the exercise of options shall be appropriately increased or decreased
proportionately, and appropriate adjustments shall be made in the purchase price
per share to reflect such subdivision, combination or stock dividend.

          (b)  ISSUANCES OF SECURITIES. Except as expressly provided herein, no
issuance by the Company of shares of stock of any class, or securities
convertible into shares of stock of any class, shall affect, and no adjustment
by reason thereof shall be made with respect to, the number or price of shares
subject to options. No adjustments shall be made for dividends paid in cash or
in property other than securities of the Company.

          (c)  ADJUSTMENTS. Upon the happening of any of the foregoing events,
the class and aggregate number of shares set forth in paragraph 2 of this Plan
that are subject to options which previously have been or subsequently may be
granted under this Plan shall also be appropriately adjusted to reflect such
events. The Board shall determine the specific adjustments to be made under this
paragraph 10 and its determination shall be conclusive.

<PAGE>   6

                                      -6-

     11.  RESTRICTIONS ON ISSUANCE OF SHARES. Notwithstanding the provisions of
paragraphs 4 and 9 of this Plan, the Company shall have no obligation to deliver
any certificate or certificates upon exercise of an option until one of the
following conditions shall be satisfied:

          (a)  The shares with respect to which the option has been exercised
are at the time of the issue of such shares effectively registered under
applicable Federal and state securities laws as now in force or hereafter
amended; or

          (b)  Counsel for the Company shall have given an opinion that such
shares are exempt from registration under Federal and state securities laws as
now in force or hereafter amended; and the Company has complied with all
applicable laws and regulations with respect thereto, including without
limitation all regulations required by any stock exchange upon which the
Company's outstanding Common Stock is then listed.

     12.  REPRESENTATION OF OPTIONEE. If requested by the Company, the optionee
shall deliver to the Company written representations and warranties upon
exercise of the option that are necessary to show compliance with Federal and
state securities laws, including representations and warranties to the effect
that a purchase of shares under the option is made for investment and not with a
view to their distribution (as that term is used in the Securities Act of 1933).

     13.  OPTION AGREEMENT. Each option granted under the provisions of this
Plan shall be evidenced by an option agreement, which agreement shall be duly
executed and delivered on behalf of the Company and by the optionee to whom such
option is granted. The option agreement shall contain such terms, provisions and
conditions not inconsistent with this Plan as may be determined by the officer
executing it.

     14.  TERMINATION AND AMENDMENT OF PLAN. Options may no longer be granted
under this Plan after March 2, 2002, and this Plan shall terminate when all
options granted or to be granted hereunder are no longer outstanding. The Board
may at any time terminate this Plan or make such modification or amendment
thereof as it deems advisable; provided, however, that the Board may not,
without approval by the affirmative vote of the holders of a majority of the
shares of Common Stock present in person or by proxy and entitled to vote at the
meeting, (a) increase the maximum number of shares for which options may be
granted under this Plan or the number of shares for which an option may be
granted to any participating director hereunder, (b) change the provisions of
this Plan regarding the termination of the options or the times when they may be
exercised, (c) change the period during which any options may be granted or
remain outstanding or the date on which this Plan shall terminate, (d) change
the designation of the class of persons eligible to receive options, or
otherwise change paragraph 4, (e) materially increase benefits accruing to
option holders under this Plan, or (f) amend this Plan in any manner which would
cause Rule 16b-3 to become inapplicable to this Plan; and provided further that
the provisions of this Plan specified in Rule 16b-3(c)(2)(ii)(A) may not be
amended more than once every six months, other than to comport with changes in
the Internal Revenue Code, the Employee Retirement Income Security Act, or the
rules thereunder. Termination or any modification or amendment of this Plan
shall not, without consent of a participant, affect his or her rights under an
option previously granted to him or her.

<PAGE>   7

                                      -7-

     15.  By accepting options under the Plan, each optionee acknowledges that
the Company may be required to withhold taxes in connection with the exercise of
such options in respect of amounts considered to be compensation includible in
the optionee's gross income.

     16.  GOVERNING LAW. The validity and construction of this Plan and the
instruments evidencing options shall be governed by the laws of the State of
Delaware, without giving effect to the principles of conflicts of law thereof.

<PAGE>   8

                                      -8-

Register of Amendments:

<TABLE>
<CAPTION>
                                                          Date of Board              Date of Shareholder
                                                             Approval                      Approval
                                                          -------------              -------------------
<S>                                                  <C>                        <C>
1.   Annual Option grants introduced                     March 31, 1995                  June 2, 1995

2.   -   Initial Option grants increased to               April 5, 1996                  June 7, 1996
         10,000 shares;
     -   Annual Option grants amended to
         10,000 shares per year; and
     -   Partial Annual Option grants
         adopted for new directors.
     -   Update Company Address.

3.   Increase the number of shares of                    April 24, 2000                  June 16, 2000
     Common Stock authorized for
     issuance from 215,000 shares to
     465,000 shares.
</TABLE>

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