THIS
      WARRANT AND ANY SHARES ACQUIRED UPON THE EXERCISE OF THIS WARRANT HAVE NOT
      BEEN
      REGISTERED UNDER THE SECURITIES ACT OF 1933 AND MAY NOT BE TRANSFERRED, SOLD
      OR
      OTHERWISE DISPOSED OF EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT
      UNDER SUCH ACT OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY
      THAT REGISTRATION IS NOT REQUIRED UNDER SUCH ACT.





**PROTEIN
      POLYMER TECHNOLOGIES, INC.**





**COMMON
      STOCK PURCHASE WARRANT**





**_____________,
      200_**





THIS
      COMMON STOCK PURCHASE WARRANT (this “ **Warrant** ”)
      of
      Protein Polymer Technologies, Inc., a corporation duly organized and validly
      existing under the laws of the State of Delaware (the “ **Company** ”),
      is
      issued to the Holder (as defined below).





FOR
      VALUE
      RECEIVED, the Company hereby certifies that the registered holder hereof and
      its
      successors and assigns, ___________ (the “ Holder ”)
      is
      entitled to purchase from the Company _______ duly authorized, validly issued,
      fully paid and nonassessable shares of common stock of the Company, par value
      $0.01 per share (the “ Common
      Stock ”),
      at a
      purchase price per share equal to $_____, as may be adjusted to the
      anti-dilution provisions set forth herein (the “ Warrant
      Price ”).
      The
      person or entity in whose name this Warrant (or one or more predecessor
      Warrants) is registered on the records of the Company regarding registration
      and
      transfers of the Warrant (the “ Warrant
      Register ”)
      is the
      owner and holder thereof for all purposes, except as described in Section
      11 hereof.





1.  Vesting
      of Warrant .
      This
      Warrant shall vest and become exercisable as of the date hereof.





2.  Expiration
      of Warrant .
      This
      Warrant shall expire on _________ (the “ Expiration
      Date ”).





3.  Exercise
      of Warrant .
      This
      Warrant shall be exercisable pursuant to the terms of Section
      1 and this Section
      3 hereof.





3.1  Manner
      of
      Exercise. This Warrant may only be exercised by the Holder hereof, in accordance
      with the terms and conditions hereof, in whole or in part with respect to any
      portion of the Warrant, into shares of Common Stock, during normal business
      hours on any day other than a Saturday or a Sunday or a day on which commercial
      banking institutions in New York, New York are authorized by law to be closed
      (a
“ Business
      Day ”)
      on or
      prior to the Expiration Date with respect to such portion of the Warrant, by
      surrender of this Warrant to the Company at its office maintained pursuant
      to Section
      11.2(a) hereof,
      accompanied by an exercise notice in substantially the form attached to this
      Warrant as Exhibit
      A (or a
      reasonable facsimile thereof) duly executed by the Holder, together with the
      payment of the Warrant Price.








3.2   When
      Exercise Effective. Each exercise of this Warrant shall be deemed to have been
      effected immediately prior to the close of business on the Business Day on
      which
      this Warrant shall have been surrendered to the Company as provided in Section
      3.1 hereof,
      and, at such time, the corporation, association, partnership, organization,
      business, individual, government or political subdivision thereof or a
      governmental agency (a “ Person ”
or
      the
“ Persons ”)
      in
      whose name or names any certificate or certificates for shares of Common Stock
      shall be issuable upon exercise as provided in Section
      3.3 hereof
      shall be deemed to have become the holder or holders of record thereof.





3.3   Delivery
      of Stock Certificates. As soon as practicable after each exercise of this
      Warrant, in whole or in part, and in any event within fifteen (15) Business
      Days
      thereafter, the Company at its expense (including the payment by it of any
      applicable issue taxes) will cause to be issued in the name of and delivered
      to
      the Holder hereof or, subject to Section
      10 hereof,
      as the Holder (upon payment by the Holder of any applicable transfer taxes)
      may
      direct:





(a)
      a
      certificate or certificates (with appropriate restrictive legends, as
      applicable) for the number of duly authorized, validly issued, fully paid and
      nonassessable shares of Common Stock to which the Holder shall be entitled
      upon
      exercise plus, in lieu of any fractional share to which the Holder would
      otherwise be entitled, all issuances of Common Stock shall be rounded up to
      the
      nearest whole share.





(b)
      in
      case exercise is in part only, a new Warrant of like tenor, dated the date
      hereof and calling in the aggregate on the face thereof for the number of shares
      of Common Stock equal to the number of shares called for on the face of this
      Warrant minus the number of shares designated by the Holder upon exercise as
      provided in Section
      3.1 hereof
      (without giving effect to any adjustment thereof).





3.4   Company
      to Reaffirm Obligations. The Company will, at the time of each exercise of
      this
      Warrant, upon the written request of the Holder hereof, acknowledge in writing
      its continuing obligation to afford to the Holder all rights (including without
      limitation any rights to registration of the shares of Common Stock issued
      upon
      exercise) to which the Holder shall continue to be entitled after exercise
      in
      accordance with the terms of this Warrant; provided , however ,
      that if
      the Holder shall fail to make a request, the failure shall not affect the
      continuing obligation of the Company to afford the rights to such
      Holder.





4.  Adjustment
      of Common Stock Issuable Upon Exercise .
      The
      Warrant Price shall be subject to be adjusted and re-adjusted from time to
      time
      as provided in this Section
      4 and, as
      so adjusted or re-adjusted, shall remain in effect until a further adjustment
      or
      re-adjustment thereof is required by this Section
      4 :


2





4.1   Stock
      Dividends; Stock Splits. In case the Company at any time or from time to time
      after the date hereof shall declare or pay any dividend on the Common Stock
      payable in Common Stock, or shall effect a subdivision of the outstanding shares
      of Common Stock into a greater number of shares of Common Stock (by
      reclassification or otherwise than by payment of a dividend in Common Stock),
      then, and in each case, subject to Section
      4.3 hereof,
      the Warrant Price shall be reduced, concurrently with the dividend or
      subdivision, to a price determined by multiplying the Warrant Price by a
      fraction:





(a)
      the
      numerator of which shall be the number of shares of Common Stock outstanding
      immediately prior to the dividend or subdivision; and





(b)
      the
      denominator of which shall be the number of shares of Common Stock outstanding
      immediately after the dividend or subdivision.





Additional
      shares of Common Stock shall be deemed to have been issued and to be outstanding
      (a) in the case of any dividend, immediately after the close of business on
      the
      record date for the determination of holders of any class of securities entitled
      to receive the dividend, or (b) in the case of any subdivision, at the close
      of
      business on the day immediately prior to the day upon which the corporate action
      becomes effective. Additional shares of Common Stock deemed to have been issued
      pursuant to this Section
      4.1 shall be
      deemed to have been issued for no consideration.





4.2  Subscription
      Offerings. In case the Company shall issue to stockholders or otherwise rights,
      options, or warrants entitling the holders thereof to subscribe for or purchase
      Common Stock (or securities convertible into or exchangeable for Common Stock)
      at a price per share (or having a conversion price per share, in the case of
      a
      security convertible into or exchangeable for Common Stock) less than the lower
      of the then Exercise Price or the Current Market Price per share (as defined
      in Paragraph
      4.4 below)
      on the record date for the determination of stockholders entitled to receive
      such rights, or otherwise on the granting date, as the case may be, then in
      each
      such case the Exercise Price shall be adjusted by multiplying the Exercise
      Price
      in effect immediately prior to such record or granting date, as the case may
      be,
      by a fraction, of which the numerator shall be the number of shares of Common
      Stock outstanding on such record or granting date plus the number of shares
      of
      Common Stock which the aggregate offering price of the total number of shares
      of
      Common Stock so to be offered (or the aggregate initial conversion price of
      the
      convertible securities so to be offered) would purchase at such Exercise Price
      or Current Market Price, as the case may be, and of which the denominator shall
      be the number of shares of Common Stock outstanding on such record or granting
      date plus the number of additional shares of Common Stock to be offered for
      subscription or purchase (or into which the convertible or exchangeable
      securities so to be offered are initially convertible or exchangeable). Such
      adjustment shall become effective at the close of business on such record date
      or granting date, as the case may be; provided , however ,
      that,
      to the extent the shares of Common Stock (or securities convertible into or
      exchangeable for shares of Common Stock) are not delivered, the Exercise Price
      shall be readjusted after the expiration of such rights, options, or warrants
      (but only to the extent that the Warrants are not exercised after such
      expiration), to the Exercise Price which would then be in effect had the
      adjustments made upon the issuance of such rights or warrants been made upon
      the
      basis of delivery of only the number of shares of Common Stock (or securities
      convertible into or exchangeable for shares of Common Stock) actually issued.
      In
      case any subscription price may be paid in a consideration part or all of which
      shall be in a form other than cash, the value of such consideration shall be
      as
      determined in good faith by the Company's Board of Directors. Shares of Common
      Stock owned by or held for the account of the Company or any majority-owned
      subsidiary shall not be deemed outstanding for the purpose of any such
      computation.


3





4.3  Other
      Rights to Acquire Common Stock. In case the Company shall distribute to all
      holders of its Common Stock evidences of its indebtedness or assets (excluding
      cash dividends or distributions paid from retained earnings of Maker) or rights
      or warrants to subscribe or purchase Common stock (excluding those referred
      to
      in Paragraph
      4.2 above),
      then in each such case the Exercise Price shall be adjusted so that the same
      shall equal the price determined by multiplying the Exercise Price in effect
      immediately prior to the date of such distribution by a fraction of which the
      numerator shall be the Current Market Price per share (as defined in Paragraph
      4.4 below)
      of the Common Stock on the Record Date mentioned below less the then fair market
      value (as determined in good faith by the Board of Directors of the Company)
      of
      the portion of the assets or evidences of indebtedness so distributed or of
      such
      rights or warrants applicable to one share of Common Stock, and the denominator
      shall be the Current Market Price per share of the Common Stock. Such adjustment
      shall become effective immediately after the Record Date for the determination
      of shareholders entitled to receive such distribution.





4.4   For
      the
      purpose of any computation under Paragraph
      4.2 **** and **** 3 of this Section
      4 ,
      the
      Current Market Price per share of Common Stock on any date shall be deemed
      to be
      the average of the daily closing prices for the 30 consecutive trading days
      commencing 45 trading days before such date. The closing price for each day
      shall be the last reported sales price regular way or, in case no such reported
      sale takes place on such day, the closing bid price regular way, in either
      case
      on the principal national securities exchange on which the Common Stock is
      listed or admitted to trading or, if the Common Stock is not listed or admitted
      to trading on any national securities exchange, the highest reported bid price
      as furnished by the National Association of Securities Dealers, Inc. through
      NASDAQ or similar organization if NASDAQ is no longer reporting such
      information, or by the Pink Sheets, LLC or similar organization if the Common
      Stock is not then quoted on an inter-dealer quotation system. If on any such
      date the Common Stock is not quoted by any such organization, the fair value
      of
      the Common Stock on such date, as determined in good faith by the Company's
      Board of Directors, shall be used.





4.5   Adjustments
      for Combinations. In case the outstanding shares of Common Stock shall be
      combined or consolidated, by reclassification or otherwise, into a lesser number
      of shares of Common Stock, the Warrant Price in effect immediately prior to
      the
      combination or consolidation shall, concurrently with the effectiveness of
      such
      combination or consolidation, be proportionately increased. Adjustment under
      this Section
      4.5 shall
      become effective at the close of business on the day immediately prior to the
      day upon which the corporate action becomes effective.


4





4.6   Minimum
      Adjustment of Warrant Price. If the amount of any adjustment of the Warrant
      Price required pursuant to this Section
      4 would be
      less than one percent (1%) of the Warrant Price in effect at the time of the
      adjustment is otherwise so required to be made, the amount shall be carried
      forward and adjustment with respect thereto made at the time of and together
      with any subsequent adjustment which, together with the amount and any other
      amount or amounts so carried forward, shall aggregate at least one percent
      (1%)
      of the Warrant Price.





5.   Adjustments
      for Consolidation, Merger, Sale of Assets or Reorganization .
      In case
      the Company after the date hereof (a) shall consolidate with or merge into
      any
      other Person and shall not be the continuing or surviving corporation following
      the consolidation or merger, or (b) shall permit any other Person to consolidate
      with or merge into the Company and the Company shall be the continuing or
      surviving Person but, in connection with the consolidation or merger, the Common
      Stock shall be changed into or exchanged for stock or other securities of any
      other Person or cash or any other property, or (c) shall transfer all or
      substantially all of its properties or assets to any other Person, or (d) shall
      effect a capital reorganization or reclassification of the Common Stock, then,
      and in the case of each such transaction, proper provision shall be made so
      that, upon the basis and the terms and in the manner provided in this Warrant,
      the Holder, upon the exercise hereof at any time after the consummation of
      the
      transaction, shall be entitled to receive (at the aggregate Warrant Price in
      effect at the time of such consummation for all Common Stock issuable upon
      exercise immediately prior to the consummation), in lieu of the Common Stock
      issuable upon exercise prior to the consummation, the greatest amount of
      securities, cash or other property to which the Holder would actually have
      been
      entitled as a stockholder upon such consummation if the Holder had exercised
      the
      rights represented by this Warrant immediately prior thereto, subject to
      adjustments (subsequent to the consummation) as nearly equivalent as possible
      to
      the adjustments provided for in Sections
      4 and 5 hereof.





6.  No
      Dilution or Impairment .





6.1   The
      Company will not, by amendment of its certificate of incorporation or through
      any consolidation, merger, reorganization, transfer of assets, dissolution,
      issue or sale of securities or any other voluntary action, avoid or seek to
      avoid the observance or performance of any of the terms of this Warrant, but
      will at all times in good faith assist in the carrying out of all of the terms
      and in the taking of all actions necessary or appropriate in order to protect
      the rights of the Holder. Without limiting the generality of the foregoing,
      the
      Company (a) will not permit the par value of any shares of Common Stock
      receivable upon the exercise of this Warrant to exceed the amount payable
      therefor upon exercise, (b) will take all actions necessary or appropriate
      in
      order that the Company may validly and legally issue fully paid and
      nonassessable shares of Common Stock on the exercise of the Warrant and (c)
      will
      not take any action which results in any adjustment of the Warrant Price if
      the
      total number of shares of Common Stock issuable after the action upon the
      exercise of the Warrant would exceed the total number of shares of Common Stock
      then authorized by the Company's certificate of incorporation and available
      for
      the purpose of issuance upon exercise.


5





6.2   The
      Company acknowledges that its obligation to issue shares of Common Stock
      issuable upon exercise of this Warrant is binding upon it and enforceable
      regardless of the dilution that such issuance may have on the ownership
      interests of other stockholders.





7.  Chief
      Financial Officer’s Report as to Adjustments .
      In the
      case of any adjustment or re-adjustment in the shares of Common Stock issuable
      upon the exercise of this Warrant, the Company at its expense will promptly
      compute the adjustment or re-adjustment in accordance with the terms of this
      Warrant and cause its Chief Financial Officer to certify the computation (other
      than any computation of the fair value of property as determined in good faith
      by the Board of Directors of the Company) and prepare a report setting forth
      the
      adjustment or re-adjustment and showing in reasonable detail the method of
      calculation thereof and the facts upon which the adjustment or re-adjustment
      is
      based, including a statement of (a) the number of shares of Common Stock
      outstanding or deemed to be outstanding and (b) the Warrant Price in effect
      immediately prior to the deemed issuance or sale and as adjusted and re-adjusted
      (if required by Section
      4 hereof)
      on account thereof. The Company will forthwith mail a copy of each report to
      each holder of a Warrant and will, upon the written request at any time of
      any
      holder of a Warrant, furnish to the holder a like report setting forth the
      Warrant Price at the time in effect and showing in reasonable detail how it
      was
      calculated. The Company will also keep copies of all reports at its office
      maintained pursuant to Section
      11.2(a) hereof
      and will cause them to be available for inspection at the office during normal
      business hours upon reasonable notice by any holder of a Warrant or any
      prospective purchaser of a Warrant designated by the holder
      thereof.





8.  Reservation
      of Shares .
      The
      Company shall at all times reserve and keep available out of its authorized
      but
      unissued shares of Common Stock, free from all taxes, liens and charges with
      respect to the issue thereof and not be subject to preemptive rights or other
      similar rights of stockholders of the Company, solely for the purpose of
      effecting the exercise of this Warrant, such number of its shares of Common
      Stock as shall from time to time be sufficient to effect the exercise thereof,
      and if at any time the number of authorized but unissued shares of Common Stock
      shall not be sufficient to effect the exercise of this Warrant, in addition
      to
      such other remedies as shall be available to Holder, the Company will take
      such
      corporate action as may, in the opinion of its counsel, be necessary to increase
      the number of authorized but unissued shares of Common Stock to such number
      of
      shares as shall be sufficient for such purposes, including without limitation,
      using its best efforts to obtain the requisite stockholder approval necessary
      to
      increase the number of authorized shares of the Company’s Common Stock. All
      shares of Common Stock issuable upon exercise of the Warrant shall be duly
      authorized and, when issued upon exercise, shall be validly issued and, in
      the
      case of shares, fully paid and nonassessable.


6





9.  Listing .
      The
      Company shall at all times comply in all respects with the Company’s reporting,
      filing and other obligations under the by-laws or rules of the upon each
      national securities exchange or automated quotation system upon which shares
      of
      Common Stock are then listed and shall list the shares issuable upon the
      exercise of this Warrant on such national securities exchange.





10.  Restrictions
      on Transfer .





10.1  Restrictive
      Legends. This Warrant and each Warrant issued upon transfer or in substitution
      for this Warrant pursuant to Section
      11 ,
      each
      certificate for Common Stock issued upon the exercise of any Warrant and each
      certificate issued upon the transfer of any such Common Stock shall be
      transferable only upon satisfaction of the conditions specified in this Section
      10 .
      Each of
      the foregoing securities shall be stamped or otherwise imprinted with a legend
      reflecting the restrictions on transfer set forth in Section
      10 hereof
      and any restrictions required under the Securities Act of 1933 (the
“ Act ”).





10.2  Notice
      of
      Proposed Transfer; Opinion of Counsel. Prior to any transfer of any securities
      that are not registered under an effective registration statement under the
      Act
      (“ Restricted
      Securities ”),
      the
      Holder will give written notice to the Company of the Holder's intention to
      affect a transfer and to comply in all other respects with this Section
      10.2 .
      Each
      notice (a) shall describe the manner and circumstances of the proposed transfer,
      and (b) shall designate counsel for the Holder giving the notice (who may be
      in-house counsel for the Holder). The Holder giving notice will submit a copy
      thereof to the counsel designated in the notice. The following provisions shall
      then apply:





(i)
      If in
      the opinion of counsel for the Holder reasonably satisfactory to the Company
      the
      proposed transfer (i.e. private sale of Restricted Securities) may be effected
      without registration of Restricted Securities under the Act (which opinion
      shall
      state the basis of the legal conclusions reached therein), the Holder shall
      thereupon be entitled to transfer the Restricted Securities in accordance with
      the terms of the notice delivered by the Holder to the Company. Each certificate
      representing the Restricted Securities issued upon or in connection with any
      transfer shall bear the restrictive legends required by Section
      10.1 hereof.





(ii)
      If
      the opinion called for in (i) above is not delivered, the Holder shall not
      be
      entitled to transfer the Restricted Securities until either (x) receipt by
      the
      Company of a further notice from such Holder pursuant to the foregoing
      provisions of this Section
      10.2 and
      fulfillment of the provisions of clause (i) above, or (y) such Restricted
      Securities have been effectively registered under the Act.


7




10.3  Termination
      of Restrictions. The restrictions imposed by this Section
      10 upon the
      transferability of Restricted Securities shall cease and terminate as to any
      particular Restricted Securities: (a) which Restricted Securities shall have
      been effectively registered under the Act, or (b) when, in the opinions of
      both
      counsel for the holder thereof and counsel for the Company, which opinion shall
      not be unreasonably withheld, such restrictions are no longer required in order
      to insure compliance with the Act or Section
      10 hereof.
      Whenever such restrictions shall cease and terminate as to any Restricted
      Securities, the Holder thereof shall be entitled to receive from the Company,
      without expense (other than applicable transfer taxes, if any), new securities
      of like tenor not bearing the applicable legends required by Section
      10.1 hereof.





11.  Ownership,
      Transfer and Substitution of Warrant .





11.1  Ownership
      of Warrant. The Company may treat the person in whose name this Warrant is
      registered to in the Warrant Register maintained pursuant to Section
      11.2(b) hereof
      as the owner and holder thereof for all purposes, notwithstanding any notice
      to
      the contrary, except that, if and when any Warrant is properly assigned by
      a
      notice in substantially the form attached to this Warrant as Exhibit
      C (or a
      reasonable facsimile thereof) duly executed by the Holder in blank, the Company
      shall treat the bearer thereof as the owner of such Warrant for all purposes,
      notwithstanding any notice to the contrary. Subject to Section
      10 hereof,
      this Warrant, if properly assigned, may be exercised by a new holder without
      a
      new Warrant first having been issued.





11.2  Office;
      Transfer and Exchange of Warrant.





(a)
      The
      Company will maintain an office (which may be an agency maintained at a bank)
      at
      11494 Sorrento Valley Road, San Diego, California 92121 (until the Company
      notifies the Holder of any change of location of the office) where notices,
      presentations and demands in respect of this Warrant may be made upon
      it.





(b)
      The
      Company shall cause to be kept at its office maintained pursuant to Section
      11.2(a) hereof a
      Warrant Register for the registration and transfer of the Warrant. The names
      and
      addresses of holders of the Warrant, the transfers thereof and the names and
      addresses of transferees of the Warrant shall be registered in such Warrant
      Register. The Person in whose name any Warrant shall be so registered shall
      be
      deemed and treated as the owner and holder thereof for all purposes of this
      Warrant, and the Company shall not be affected by any notice or knowledge to
      the
      contrary.





(c)
      Upon
      the surrender of this Warrant, properly endorsed, for registration of transfer
      or for exchange at the office of the Company maintained pursuant to Section
      11.2(a )
      hereof,
      the Company at its expense will (subject to compliance with Section
      10 hereof,
      if applicable) execute and deliver to or upon the order of the Holder thereof
      a
      new Warrant of like tenor, in the name of such holder or as such holder (upon
      payment by such holder of any applicable transfer taxes) may direct, calling
      in
      the aggregate on the face thereof for the number of shares of Common Stock
      called for on the face of the Warrant so surrendered.


8





11.3  Replacement
      of Warrant. Upon receipt of evidence reasonably satisfactory to the Company
      of
      the loss, theft, destruction or mutilation of the Warrant and, in the case
      of
      any such loss, theft or destruction of the Warrant, upon delivery of indemnity
      reasonably satisfactory to the Company in form and amount or, in the case of
      any
      mutilation, upon surrender of the Warrant for cancellation at the office of
      the
      Company maintained pursuant to Section
      11.2(a) hereof,
      the Company at its expense will execute and deliver, in lieu thereof, a new
      Warrant of like tenor and dated the date hereof.





12.  No
      Rights or Liabilities as Stockholder .
      Except
      as may otherwise be provided herein, no Holder shall be entitled to vote or
      receive dividends or be deemed the holder of any shares of Common Stock or
      any
      other securities of the Company which may at any time be issuable on the
      exercise hereof for any purpose, nor shall anything contained herein be
      construed to confer upon the Holder, as such, any of the rights of a stockholder
      of the Company or any right to vote for the election of directors or upon any
      matter submitted to stockholders at any meeting thereof, or to give or withhold
      consent to any corporate action (whether upon any recapitalization, issuance
      of
      stock, reclassification of stock, change of par value, consolidation, merger,
      conveyance, or otherwise) or to receive notice of meetings, or to receive
      dividends or subscription rights or otherwise until the Warrant shall have
      been
      exercised and the shares of Common Stock purchasable upon the exercise hereof
      shall have become deliverable, as provided herein. The Holder will not be
      entitled to share in the assets of the Company in the event of liquidation,
      dissolution or the winding up of the Company.





13.  Notices .
      Any
      notice or other communication in connection with this Warrant shall be deemed
      to
      be given if in writing (or in the form of a facsimile) addressed as hereinafter
      provided and actually delivered at such address: (a) if to any Holder, at the
      registered address of such holder as set forth in the Warrant Register kept
      at
      the office of the Company maintained pursuant to Section
      11.2(a) hereof,
      or (b )
      if to
      the Company, to the attention of its Chief Financial Officer at its office
      maintained pursuant to Section
      11.2(a) hereof; provided , however ,
      that
      the exercise of any Warrant shall be effective in the manner provided in Section
      3 hereof.





14.  Payment
      of Taxes .
      The
      Company will pay all documentary stamp taxes attributable to the issuance of
      shares of Common Stock underlying this Warrant upon exercise of this Warrant; provided , however ,
      that
      the Company shall not be required to pay any tax which may be payable in respect
      of any transfer involved in the registration of any certificate for shares
      of
      Common Stock underlying this Warrant in a name other that of the Holder. The
      Holder is responsible for all other tax liability that may arise as a result
      of
      holding or transferring this Warrant or receiving shares of Common Stock
      underlying this Warrant upon exercise hereof.





15.  Warrant
      Agent .
      The
      Company shall serve as warrant agent under this Warrant. Upon thirty (30) days
      notice to the Holder, the Company may appoint a new warrant agent. Any
      corporation into which the Company or any new warrant agent may be merged or
      any
      corporation resulting from any consolidation to which the Company or any new
      warrant agent shall be a party or any corporation to which the Company or any
      new warrant agent transfers substantially all of its corporate trust or
      stockholders services business shall be successor warrant agent under this
      Warrant without any further act. Any such successor warrant agent shall promptly
      cause notice of its succession as warrant agent to be mailed (by first class
      mail, postage prepaid) to the Holder at the Holder’s last address as shown on
      the Warrant Register.


9





16.  Miscellaneous .
      This
      Warrant and any term hereof may be changed, waived, discharged or terminated
      only by an instrument in writing signed by the party against which enforcement
      of the change, waiver, discharge or termination is sought. This Warrant shall
      be
      construed and enforced in accordance with and governed by the laws of the State
      of Delaware. The section headings in this Warrant are for purposes of
      convenience only and shall not constitute a part hereof.





IN
      WITNESS WHEREOF, the Company has caused this Common Stock Purchase Warrant
      to be
      duly executed as of the date first above written.





**PROTEIN
                POLYMER TECHNOLOGIES, INC.**By:Name:
            James
                B. McCarthyTitle:
            InterimPresident and Interim Chief Executive
                Officer


10


**EXHIBIT
      A**





FORM
      OF
      EXERCISE NOTICE





[To
      be
      executed only upon conversion of Warrant]





To PROTEIN
      POLYMER TECHNOLOGIES, INC.:





The
      undersigned registered holder of the within Warrant hereby irrevocably exercises
      the Warrant pursuant to Section
      3.1 of the
      Warrant with respect to __________(1) shares of the Common Stock, at an exercise
      price per share of Common Stock of $____, which the holder would be entitled
      to
      receive upon the cash exercise hereof, and requests that the certificates for
      the shares be issued in the name of, and delivered to, whose address
      is:





Dated:
      _______________




Print
                or Type Name(Signature
                must conform in all respects to name of holder as specified on the
                face of
                Warrant)(Street
                Address)(City)               
                        (State)              
                (Zip Code)




_______________________


(1)
      Insert here the number of shares called for on the face of this Warrant (or,
      in
      the case of a partial exercise, the portion thereof as to which this Warrant
      is
      being exercised), in either case without making any adjustment of shares of
      Common Stock or any other stock or other securities or property or cash which,
      pursuant to the adjustment provisions of this Warrant, may be delivered upon
      exercise. In the case of a partial exercise, a new Warrant or Warrants will
      be
      issued and delivered, representing the unconverted portion of the Warrant,
      to
      the holder surrendering the Warrant.


11


**EXHIBIT
      B**





FORM
      OF
      ASSIGNMENT





[To
      be
      executed only upon transfer of Warrant]





For
      value
      received, the undersigned registered holder of the within Warrant hereby sells,
      assigns and transfers unto _____________________ the right represented by the
      Warrant to purchase __________(1) shares of Common Stock of PROTEIN POLYMER
      TECHNOLOGIES, INC. to which the Warrant relates, and appoints
      _____________________ Attorney to make such transfer on the books of PROTEIN
      POLYMER TECHNOLOGIES, INC. maintained for the purpose, with full power of
      substitution in the premises.





Dated:


(Signature
                must conform in all respectsto
                name of holder as specified on theface
                of Warrant)(Street
                Address)(City)      
                       
                (State)               (Zip
                Code)




Signed
      in
      the presence of:





(Signature
                of Transferee)(Street
                Address)(City)               (State)               (Zip
                Code)


Signed
      in
      the presence of:





_______________________


(1)
      Insert here the number of shares called for on the face of this Warrant (or,
      in
      the case of a partial exercise, the portion thereof as to which this Warrant
      is
      being exercised), in either case without making any adjustment of shares of
      Common Stock or any other stock or other securities or property or cash which,
      pursuant to the adjustment provisions of this Warrant, may be delivered upon
      exercise. In the case of a partial exercise, a new Warrant or Warrants will
      be
      issued and delivered, representing the unexercised portion of the Warrant,
      to
      the holder surrendering the Warrant.




12