**EXHIBIT
      4.1**




**REGISTRATION
      RIGHTS AGREEMENT**




This
      Registration Rights Agreement (this "Agreement") is made and entered into as
      of
      September 27, 2007, by and between Protein
      Polymer Technologies ,
      Inc., a
      Delaware corporation (the " Company "),
      and TAG
      Virgin Islands, Inc . ,
      with an
      address at The
      Tunick Building , 1336
      Beltjen Road, Suite 202, St. Thomas, USVI 00802 as agent for the purchasers
      listed on the Schedule
      of Purchasers appended
      hereto as Schedule
      I ,
      which
      may be amended from time to time to add additional purchasers (collectively, the “ Purchasers ”).




This
      Agreement is made pursuant to the Stock Purchase Agreement, dated as of
      September 27, 2007, by and between the Purchasers and the Company (as amended,
      modified or supplemented from time to time, the “ Purchase
      Agreement ”).
      The
      Company and the Purchasers hereby agree as follows:




1.  Definitions .
      Capitalized terms used and not otherwise defined herein that are defined in
      the
      Purchase Agreement shall have the meanings given such terms in the Purchase
      Agreement. As used in this Agreement, the following terms shall have the
      following meanings:




" *Commission* "
      means
      the Securities and Exchange Commission.




" *Common
      Stock* "
      means
      shares of the Company's common stock, par value $0.01 per share.




“ *Effective
      Date* ”
shall
      mean the date the Commission shall declare a Registration Statement
      effective.




" *Effectiveness
      Period* "
      shall
      have the meaning set forth in Section
      2(a) .




" *Exchange
      Act* "
      means
      the Securities Exchange Act of 1934 and any successor statute.




" *Filing
      Date* "
      means,
      (i) with respect to the initial Registration Statement required to be filed
      hereunder, a date no later than 180 days following the date hereof and (ii)
      with
      respect to shares of Common Stock issuable to the Holder as a result of
      adjustments to the Exercise Price made pursuant to the Warrants or otherwise,
      30
      days after the occurrence such event or the date of the adjustment of the
      Exercise Price, as the case may be.




" *Holder* "
      or
      " *Holders* "
      means
      each Purchaser or any of his affiliates or transferees to the extent any of
      them
      hold Registrable Securities.




" *Indemnified
      Party* "
      shall
      have the meaning set forth in Section
      5(c ).




" *Indemnifying
      Party* "
      shall
      have the meaning set forth in Section
      5(c) .









“ *Person* ”
means
      an individual, partnership, limited liability company, corporation, joint stock
      company, trust, estate, joint venture, association or unincorporated
      organization, or any other form of business or professional entity,




" *Proceeding* "
      means
      an action, claim, suit, investigation or proceeding (including, without
      limitation, an investigation or partial proceeding, such as a deposition),
      whether commenced or threatened.




" *Prospectus* "
      means
      the prospectus included in the Registration Statement (including, without
      limitation, a prospectus that includes any information previously omitted from
      a
      prospectus filed as part of an effective registration statement in reliance
      upon
      Rule 430A promulgated under the Securities Act), as amended or supplemented
      by
      any prospectus supplement, with respect to the terms of the offering of any
      portion of the Registrable Securities covered by the Registration Statement,
      and
      all other amendments and supplements to the Prospectus, including post-effective
      amendments, and all material incorporated by reference or deemed to be
      incorporated by reference in such Prospectus.




" *Purchase
      Agreement* "
      shall
      have the meaning provided above.




" *Registrable
      Securities* "
      means
      the Shares and the shares of Common Stock issuable upon the exercise of the
      Warrants.




" *Registration
      Statement* "
      means
      each registration statement required to be filed hereunder, including the
      Prospectus, amendments and supplements to such registration statement or
      Prospectus, including pre- and post-effective amendments, all exhibits thereto,
      and all material incorporated by reference or deemed to be incorporated by
      reference in such registration statement.




" *Rule
      144* "
      means
      Rule 144 promulgated by the Commission pursuant to the Securities Act, as such
      Rule may be amended from time to time, or any similar rule or regulation
      hereafter adopted by the Commission having substantially the same effect as
      such
      Rule.




" *Rule
      415* "
      means
      Rule 415 promulgated by the Commission pursuant to the Securities Act, as such
      Rule may be amended from time to time, or any similar rule or regulation
      hereafter adopted by the Commission having substantially the same effect as
      such
      Rule.




" *Rule
      424* "
      means
      Rule 424 promulgated by the Commission pursuant to the Securities Act, as such
      Rule may be amended from time to time, or any similar rule or regulation
      hereafter adopted by the Commission having substantially the same effect as
      such
      Rule.




" *Securities
      Act* "
      means
      the Securities Act of 1933 and any successor statute.




“ *Shares* ”
means
      the 1,875,000 shares of Common Stock purchased by the Purchasers pursuant to
      the
      terms of the Purchase Agreement on October
      19, 2007 .




" *Trading
      Market* "
      means
      any of the NASD OTCBB, NASDAQ Capital Market, the Nasdaq National Market, the
      American Stock Exchange or the New York Stock Exchange.




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“ *Warrants* ”
means,
      collectively, each Common Stock Purchase Warrant issued by the Company to the
      Purchasers as of October 19, 2007 pursuant to the Purchase Agreement to the
      extent such Common Stock Purchase Warrant is exercisable into shares of Common
      Stock and such shares of Common Stock are not otherwise subject to an effective
      Registration Statement.




2.  Registration .




(a)  On
      or
      prior to the Filing Date the Company shall prepare and file with the Commission
      a Registration Statement covering the Registrable Securities for an offering
      to
      be made on a continuous basis pursuant to Rule 415. The Company shall cause
      the
      Registration Statement to become effective and remain effective as provided
      herein. The Company shall use its best efforts to cause the Registration
      Statement to be declared effective under the Securities Act as promptly as
      possible after the filing thereof. The Company shall use its best efforts to
      keep the Registration Statement continuously effective under the Securities
      Act
      until the date which is the earlier of when (i) all Registrable Securities
      have
      been sold or (ii) all Registrable
      Securities may be
      sold immediately without registration under the Securities Act and without
      volume restrictions pursuant to Rule 144(k), as determined by the counsel to
      the
      Company pursuant to a written opinion letter to such effect, addressed and
      acceptable to the Company's transfer agent and the affected Holders (the
      " Effectiveness
      Period ").




(b)  Within
      three business days after the Effective Date of a Registration Statement, the
      Company shall cause its counsel to issue a blanket opinion in the form attached
      hereto as Exhibit
      A ,
      to its
      transfer agent stating that the Registrable Securities are subject to an
      effective registration statement and can be reissued free of restrictive legend
      upon notice of a sale by a Purchaser and confirmation by such Purchaser that
      he
      has complied with the prospectus delivery requirements, provided that the
      Company has not advised the transfer agent orally or in writing that the opinion
      has been withdrawn. Copies of the blanket opinion required by this Section
      2(b) shall be
      delivered to each Purchaser within the time period set forth above.




3.  Registration
      Procedures .
      If and
      whenever the Company is required by the provisions hereof to effect the
      registration of any Registrable Securities under the Securities Act, the Company
      will use its best efforts to within 90 days after the date hereof:




(a)  prepare
      and file with the Commission the Registration Statement with respect to such
      Registrable Securities, respond as promptly as possible to any comments received
      from the Commission, and use its best efforts to cause the Registration
      Statement to become and remain effective for the Effectiveness Period with
      respect thereto, and promptly provide to each Purchaser copies of all filings
      and Commission letters of comment relating thereto;




(b)  prepare
      and file with the Commission such amendments and supplements to the Registration
      Statement and the Prospectus used in connection therewith as may be necessary
      to
      comply with the provisions of the Securities Act with respect to the disposition
      of all Registrable Securities covered by the Registration Statement and to
      keep
      such Registration Statement effective until the expiration of the Effectiveness
      Period;




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(c)  furnish
      to each Purchaser such number of copies of the Registration Statement and the
      Prospectus included therein (including each preliminary Prospectus) as such
      Purchaser reasonably may request to facilitate the public sale or disposition
      of
      the Registrable Securities covered by the Registration Statement;




(d)  use
      its
      commercially reasonable efforts to register or qualify each Purchaser’s
      Registrable Securities covered by the Registration Statement under the
      securities or "blue sky" laws of such jurisdictions within the United States
      as
      such Purchaser may reasonably request; provided , however ,
      that
      the Company shall not for any such purpose be required to qualify generally
      to
      transact business as a foreign corporation in any jurisdiction where it is
      not
      so qualified or to consent to general service of process in any such
      jurisdiction;




(e)  list
      the
      Registrable Securities covered by the Registration Statement with any securities
      exchange on which the Common Stock of the Company is then listed;




(f)  immediately
      notify each Purchaser at any time when a Prospectus relating thereto is required
      to be delivered under the Securities Act, of the happening of any event of
      which
      the Company has knowledge as a result of which the Prospectus contained in
      such
      Registration Statement, as then in effect, includes an untrue statement of
      a
      material fact or omits to state a material fact required to be stated therein
      or
      necessary to make the statements therein not misleading in light of the
      circumstances then existing; and




(g)  make
      available for inspection by each Purchaser and any attorney, accountant or
      other
      agent retained by such Purchaser, all publicly available, non-confidential
      financial and other records, pertinent corporate documents and properties of
      the
      Company, and cause the Company's officers, directors and employees to supply
      all
      publicly available, non-confidential information reasonably requested by the
      attorney, accountant or agent of such Purchaser.




4.  Registration
      Expenses .
      All
      expenses relating to the Company's compliance with Sections
      2 and 3 hereof,
      including, without limitation, all registration and filing fees, printing
      expenses, fees and disbursements of counsel and independent public accountants
      for the Company, fees and expenses (including reasonable counsel fees) incurred
      in connection with complying with state securities or "blue sky" laws, fees
      of
      the NASD, transfer taxes, fees of transfer agents and registrars, fees of,
      and
      disbursements incurred by, one counsel for the Holders (to the extent such
      counsel is required due to Company's failure to meet any of its obligations
      hereunder), are called "Registration Expenses." All selling commissions
      applicable to the sale of Registrable Securities, including any fees and
      disbursements of any special counsel to the Holders beyond those included in
      Registration Expenses, are called "Selling Expenses." The Company shall only
      be
      responsible for all Registration Expenses.




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5.  Indemnification .




(a)  In
      the
      event of a registration of any Registrable Securities under the Securities
      Act
      pursuant to this Agreement, the Company will indemnify and hold harmless each
      Purchaser, and his officers, directors, trustees and each other Person, if
      any,
      who controls such Purchaser within the meaning of the Securities Act, against
      any losses, claims, damages or liabilities, joint or several, to which such
      Purchaser, or such Persons may become subject under the Securities Act or
      otherwise, insofar as such losses, claims, damages or liabilities (or actions
      in
      respect thereof) arise out of or are based upon any untrue statement or alleged
      untrue statement of any material fact contained in any Registration Statement
      under which such Registrable Securities were registered under the Securities
      Act
      pursuant to this Agreement, any preliminary Prospectus which has been printed
      and distributed ( *i* . *e* .
      a “red
      herring Prospectus”) or final Prospectus related thereto, or any amendment or
      supplement thereof, or arise out of or are based upon the
      omission or alleged omission to state therein a material fact required to be
      stated therein or necessary to make the statements therein not
      misleading ,
      and
      will reimburse such Purchaser, and each such Person for any reasonable legal
      or
      other expenses incurred by them in connection with investigating or defending
      any such loss, claim, damage, liability or action; provided , however ,
      that
      the Company will not be liable in any such case if and to the extent that any
      such loss, claim, damage or liability arises out of or is based upon an untrue
      statement or alleged untrue statement or omission or alleged omission so made
      in
      conformity with information furnished by or on behalf of such Purchaser or
      any
      such Person in writing specifically for use in any such document.




(b)  In
      the
      event of a registration of the Registrable Securities under the Securities
      Act
      pursuant to this Agreement, each Purchaser will indemnify and hold harmless
      the
      Company, and its officers, directors and each other Person, if any, who controls
      the Company within the meaning of the Securities Act, against all losses,
      claims, damages or liabilities, joint or several, to which the Company or such
      Persons may become subject under the Securities Act or otherwise, insofar as
      such losses, claims, damages or liabilities (or actions in respect thereof)
      arise out of or are based upon any untrue statement or alleged untrue statement
      of any material fact which was furnished in writing by such Purchaser to the
      Company expressly for use in (and such information is contained in) the
      Registration Statement under which such Registrable Securities were registered
      under the Securities Act pursuant to this Agreement, any preliminary Prospectus
      or final Prospectus contained therein, or any amendment or supplement thereof,
      or arise out of or are based upon the omission or alleged omission to state
      therein a material fact required to be stated therein or necessary to make
      the
      statements therein not misleading, and will reimburse the Company and each
      such
      Person for any reasonable legal or other expenses incurred by them in connection
      with investigating or defending any such loss, claim, damage, liability or
      action: provided , however ,
      that
      such Purchaser will be liable in any such case if and only to the extent that
      any such loss, claim, damage or liability arises out of or is based upon an
      untrue statement or alleged untrue statement or omission or alleged omission
      so
      made in conformity with information furnished in writing to the Company by
      or on
      behalf of such Purchaser specifically for use in any such document.
      Notwithstanding the provisions of this paragraph, no Purchaser shall be required
      to indemnify any Person or entity in excess of the amount of the aggregate
      net
      proceeds received by such Purchaser in respect of Registrable Securities in
      connection with any such registration under the Securities Act.




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(c)  Promptly
      after receipt by a party entitled to claim indemnification hereunder (an
      " Indemnified
      Party ")
      of
      notice of the commencement of any action, such Indemnified Party shall, if
      a
      claim for indemnification in respect thereof is to be made against a party
      hereto obligated to indemnify such Indemnified Party (an " Indemnifying
      Party "),
      notify the Indemnifying Party in writing thereof, but the omission so to notify
      the Indemnifying Party shall not relieve it from any liability which it may
      have
      to such Indemnified Party other than under this Section
      5(c) and
      shall only relieve it from any liability which it may have to such Indemnified
      Party under this Section
      5(c) if and
      to the extent the Indemnifying Party is prejudiced by such omission. In case
      any
      such action shall be brought against any Indemnified Party and he/it shall
      notify the Indemnifying Party of the commencement thereof, the Indemnifying
      Party shall be entitled to participate in and, to the extent it shall wish,
      to
      assume and undertake the defense thereof with counsel satisfactory to such
      Indemnified Party, and, after notice from the Indemnifying Party to such
      Indemnified Party of its election so to assume and undertake the defense
      thereof, the Indemnifying Party shall not be liable to such Indemnified Party
      under this Section
      5(c) for any
      legal expenses subsequently incurred by such Indemnified Party in connection
      with the defense thereof. If the Indemnified Party shall thereafter retain
      its
      own counsel, then the Indemnified Party shall pay all fees, costs and expenses
      of such counsel: provided , however ,
      that,
      if the defendants in any such action include both the indemnified party and
      the
      Indemnifying Party and the Indemnified
      Party shall
      have reasonably concluded that there may be reasonable defenses available to
      such Indemnified Party which are different from or additional to those available
      to the Indemnifying Party or if the interests of the Indemnified Party
      reasonably may be deemed to conflict with the interests of the Indemnifying
      Party, the Indemnified Party shall have the right to select one separate counsel
      and to assume such legal defenses and otherwise to participate in the defense
      of
      such action, with the reasonable expenses and fees of such separate counsel
      and
      other expenses related to such participation to be reimbursed by the
      Indemnifying Party as incurred.




(d)  In
      order
      to provide for just and equitable contribution in the event of joint liability
      under the Securities Act in any case in which either (i) a Purchaser, or any
      officer, director, controlling Person or other affiliate of such Purchaser,
      makes a claim for indemnification pursuant to this Section
      5 but it
      is judicially determined (by the entry of a final judgment or decree by a court
      of competent jurisdiction and the expiration of time to appeal or the denial
      of
      the last right of appeal) that such indemnification may not be enforced in
      such
      case notwithstanding the fact that this Section
      5 provides
      for indemnification in such case, or (ii) contribution under the Securities
      Act
      may be required on the part of such Purchaser or such officer, director,
      controlling Person or other affiliate of such Purchaser in circumstances for
      which indemnification is provided under this Section
      5 ;
      then,
      and in each such case, the Company and such Purchaser will contribute to the
      aggregate losses, claims, damages or liabilities to which they may be subject
      (after contribution from others) in such proportion so that such Purchaser
      is
      responsible only for the portion represented by the percentage that the public
      offering price of his securities offered by the Registration Statement bears
      to
      the public offering price of all securities offered by such Registration
      Statement; provided , however ,
      that,
      in any such case, (A) such Purchaser will not be required to contribute any
      amount in excess of the public offering price of all such securities offered
      by
      him pursuant to such Registration Statement; and (B) no Person guilty of
      fraudulent misrepresentation (within the meaning of Section 10(f) of the Act)
      will be entitled to contribution from any Person who was not guilty of such
      fraudulent misrepresentation.




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6.  Representations
      and Warranties .
      The
      Company represents and warrants to each Purchaser that:




(a)  The
      Common Stock of the Company is registered pursuant to Section 12(b) or 12(g)
      of
      the Exchange Act and the Company has filed all proxy statements, reports,
      schedules, forms, statements and other documents required to be filed by it
      under the Securities Act and the Exchange Act (the “ SEC
      Documents ”).
      The
      Company filed: (i) its Annual Report on Form 10-K and Form 10K/A for its fiscal
      year ended December 31, 2006, (ii) its Quarterly Report on Form 10-Q for its
      fiscal quarter ended June 30, 2007, and (iii) the Form 8-K filings which it
      has
      made during the fiscal year 2006 and 2007 to date (collectively, the
      " SEC
      Reports ").
      Each
      SEC Report was, at the time of its filing, in substantial compliance with the
      requirements of its respective form and none of the SEC Reports contain any
      untrue statement of a material fact or omit to state a material fact required
      to
      be stated therein or necessary to make the statements therein not misleading
      in
      light of the circumstances when made. To the best of the Company’s knowledge,
      the financial statements of the Company included in the SEC Reports comply
      as to
      form in all material respects with applicable accounting requirements and the
      published rules and regulations of the Commission or other applicable rules
      and
      regulations with respect thereto. Such financial statements have been prepared
      in accordance with generally accepted accounting principles (" GAAP ")
      applied on a consistent basis during the periods involved (except (i) as may
      be
      otherwise indicated in such financial statements or the notes thereto or (ii)
      in
      the case of unaudited interim statements, to the extent they may not include
      footnotes or may be condensed) and fairly present in all material respects
      the
      financial condition, the results of operations and the cash flows of the Company
      and its subsidiaries, on a consolidated basis, as of, and for, the periods
      presented in each such SEC Report. The Company is eligible to use a Registration
      Statement on Form S-3 to register the Registrable Securities.




(b)  The
      Common Stock is listed for trading on the American Stock Exchange. While the
      Company is not currently subject to delisting proceedings it will continue
      to be
      monitored by the American Stock Exchange on a quarterly basis for the reasons
      disclosed in its SEC Reports.




(c)  Neither
      the Company, nor any of its affiliates, nor any Person acting on its or their
      behalf, has directly or indirectly made any offers or sales of any security
      or
      solicited any offers to buy any security under circumstances that would cause
      the offering of the Securities pursuant to the Purchase Agreement to be
      integrated with prior offerings by the Company for purposes of the Securities
      Act which would prevent the Company from selling the Common Stock pursuant
      to
      Rule 506 under the Securities Act, or any applicable exchange-related
      stockholder approval provisions, nor will the Company or any of its affiliates
      or subsidiaries take any action or steps that would cause the offering of such
      Securities to be integrated with other offerings.




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(d)  The
      Shares and the Warrants and the shares of Common Stock that each Purchaser
      may
      acquire pursuant to the exercise of the Warrants are all restricted securities
      under the Securities Act as of the date of this Agreement. The Company will
      not
      issue any stop transfer order or other order impeding the sale and delivery
      of
      any of the Registrable Securities at such time as such Registrable Securities
      are registered for public sale or an exemption from registration is available,
      except as required by federal or state securities laws.




(e)  The
      Company understands the nature of the Registrable Securities issuable upon
      exercise of the Warrants and recognizes that the issuance of such Registrable
      Securities may have a potential dilutive effect. The Company specifically
      acknowledges that its obligation to issue the Registrable Securities is binding
      upon the Company and enforceable regardless of the dilution such issuance may
      have on the ownership interests of other shareholders of the
      Company.




(f)  Except
      for agreements made in the ordinary course of business, there is no agreement
      that has not been filed with the Commission as an exhibit to a registration
      statement or to a form required to be filed by the Company under the Exchange
      Act, the breach of which could reasonably be expected to have a material and
      adverse effect on the Company and its subsidiaries, or would prohibit or
      otherwise interfere with the ability of the Company to enter into and perform
      any of its obligations under this Agreement in any material
      respect.




(g)  The
      Company will at all times have authorized and reserved a sufficient number
      of
      shares of Common Stock for the full exercise of the Warrants.




7.  Miscellaneous .




(a)  Remedies .
      In the
      event of a breach by the Company or by a Holder, of any of their respective
      obligations under this Agreement, each Holder or the Company, as the case may
      be, in addition to being entitled to exercise all rights granted by law and
      under this Agreement, including recovery of damages, will be entitled to
      specific performance of its rights under this Agreement.




(b)  No
      Piggyback on Registrations .
      Except
      as and to the extent specified in Schedule
      7(b) hereto,
      neither the Company nor any of its security holders (other than the Holders
      in
      such capacity pursuant hereto) may include securities of the Company in any
      Registration Statement other than the Registrable Securities, and the Company
      shall not after the date hereof enter into any agreement providing any such
      right for inclusion of shares in the Registration Statement to any of its
      security holders. Except as and to the extent specified in Schedule
      7(b) hereto,
      the Company has not previously entered into any agreement granting any
      registration rights with respect to any of its securities to any Person that
      have not been fully satisfied.




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(c)  Compliance .
      Each
      Holder covenants and agrees that such Holder will comply with the prospectus
      delivery requirements of the Securities Act as applicable to it in connection
      with sales of Registrable Securities pursuant to the Registration
      Statement.




(d)  Discontinued
      Disposition .
      Each
      Holder agrees by such Holder’s acquisition of such Registrable Securities that,
      upon receipt of a notice from the Company of the occurrence of a Discontinuation
      Event (as defined below), such Holder will forthwith discontinue disposition
      of
      such Registrable Securities under the applicable Registration Statement until
      such Holder's receipt of the copies of the supplemented Prospectus and/or
      amended Registration Statement or until such Holder is advised in writing (the
      " Advice ")
      by the
      Company that the use of the applicable Prospectus may be resumed, and, in either
      case, has received copies of any additional or supplemental filings that are
      incorporated or deemed to be incorporated by reference in such Prospectus or
      Registration Statement. The Company may provide appropriate stop orders to
      enforce the provisions of this paragraph. For purposes of this Section
      7(d) ,
      a
      " Discontinuation
      Event "
      shall
      mean (i) when the Commission notifies the Company whether there will be a
      "review" of such Registration Statement and whenever the Commission comments
      in
      writing on such Registration Statement (the Company shall provide true and
      complete copies thereof and all written responses thereto to each of the
      Holders); (ii) any request by the Commission or any other federal or state
      governmental authority for amendments or supplements to such Registration
      Statement or Prospectus or for additional information; (iii) the issuance by
      the
      Commission of any stop order suspending the effectiveness of such Registration
      Statement covering any or all of the Registrable Securities or the initiation
      of
      any Proceedings for that purpose; (iv) the receipt by the Company of any
      notification with respect to the suspension of the qualification or exemption
      from qualification of any of the Registrable Securities for sale in any
      jurisdiction, or the initiation or threatening of any Proceeding for such
      purpose; and/or (v) the occurrence of any event or passage of time that makes
      the financial statements included in such Registration Statement ineligible
      for
      inclusion therein or any statement made in such Registration Statement or
      Prospectus or any document incorporated or deemed to be incorporated therein
      by
      reference untrue in any material respect or that requires any revisions to
      such
      Registration Statement, Prospectus or other documents so that, in the case
      of
      such Registration Statement or Prospectus, as the case may be, it will not
      contain any untrue statement of a material fact or omit to state any material
      fact required to be stated therein or necessary to make the statements therein,
      in light of the circumstances under which they were made, not
      misleading.




(e)  Piggy-Back
      Registrations .
      If at
      any time during the Effectiveness Period there is not an effective Registration
      Statement covering all of the Registrable Securities and the Company shall
      determine to prepare and file with the Commission a registration statement
      relating to an offering for its own account or the account of others under
      the
      Securities Act of any of its equity securities, other than on Form S-4 or Form
      S-8 (each as promulgated under the Securities Act) or their then equivalents
      relating to equity securities to be issued solely in connection with any
      acquisition of any entity or business or equity securities issuable in
      connection with stock option or other employee benefit plans, then the Company
      shall send to each Holder written notice of such determination and, if within
      15
      days after receipt of such notice, any such Holder shall so request in writing,
      the Company shall include in such registration statement all or any part of
      such
      Registrable Securities such Holder requests to be registered to the extent
      the
      Company may do so without violating registration rights of others which exist
      as
      of the date of this Agreement, subject to customary underwriter cutbacks
      applicable to all holders of registration rights and subject to obtaining any
      required consent of any selling stockholder(s) to such inclusion under such
      registration statement.




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(f)  Amendments
      and Waivers .
      The
      provisions of this Agreement, including the provisions of this sentence, may
      not
      be amended, modified or supplemented, and waivers or consents to departures
      from
      the provisions hereof may not be given, unless the same shall be in writing
      and
      signed by the Company and the Holders of the then outstanding Registrable
      Securities. Notwithstanding the foregoing, a waiver or consent to depart from
      the provisions hereof with respect to a matter that relates exclusively to
      the
      rights of certain Holders and that does not directly or indirectly affect the
      rights of other Holders may be given by Holders of at least a majority of the
      Registrable Securities to which such waiver or consent relates; provided , however ,
      that
      the provisions of this sentence may not be amended, modified, or supplemented
      except in accordance with the provisions of the immediately preceding
      sentence.




(g)  Notices .
      Any
      notice or request hereunder may be given to the Company or the Purchasers at
      the
      respective addresses set forth below or as may hereafter be specified in a
      notice designated as a change of address under this Section
      7(g) .
      Any
      notice or request hereunder shall be given by pre-paid registered or certified
      mail, return receipt requested, hand delivery, overnight mail, Federal Express
      or other national overnight next day carrier (collectively, "Courier") or
      telecopy (confirmed by mail). Notices and requests shall be, in the case of
      those by hand delivery, deemed to have been given when delivered to any party
      to
      whom it is addressed, in the case of those by mail or overnight mail, deemed
      to
      have been given three business days after the date when deposited in the mail
      or
      with the overnight mail carrier, in the case of a Courier, the next business
      day
      following timely delivery of the package with the Courier, and, in the case
      of a
      telecopy, when confirmed. The address for such notices and communications shall
      be as follows:




*If
                to the Company:*
            
            Protein
                Polymer Technologies,
                Inc.
              10655
                Sorrento Valley Road
              East
                Hanover,San
                Diego, California 92121
              Attention:Chief
                Executive Officer
              Facsimile:__________




-10-




*If
                to the Purchasers*:
            
            TAG
                Virgin Islands, Inc.
              The
                Tunick Building
              1336
                Beltjen Road
              Suite
                202
              St.
                Thomas, USVI 00802
              Attn:James
                Tagliaferri, President
              Facsimile:(340) 779 8002*If
                to any other Person who is then the registered
                Holder:*
            
            To
                the address of such Holder as it appears in the stock transfer books
                of
                the Company





or
      such
      Person may designate such other address as in writing hereafter in accordance
      with this Section 7(g).




(h)  Successors
      and Assigns .
      This
      Agreement shall inure to the benefit of and be binding upon the successors
      and
      permitted assigns of each of the parties and shall inure to the benefit of
      each
      Holder. The Company may not assign its rights or obligations hereunder without
      the prior written consent of each Holder. Each Holder may assign his respective
      rights hereunder in the manner and to the Persons as permitted under the
      Purchase Agreement.




(i)  Execution
      and Counterparts .
      This
      Agreement may be executed in any number of counterparts, each of which when
      so
      executed shall be deemed to be an original and, all of which taken together
      shall constitute one and the same Agreement. In the event that any signature
      is
      delivered by facsimile transmission, such signature shall create a valid binding
      obligation of the party executing (or on whose behalf such signature is
      executed) the same with the same force and effect as if such facsimile signature
      were the original thereof.




(j)  Governing
      Law . All
      questions concerning the construction, validity, enforcement and interpretation
      of this Agreement shall be governed by and construed and enforced in accordance
      with the internal laws of the State of Delaware, without regard to the
      principles of conflicts of law thereof. Each party agrees that all Proceedings
      concerning the interpretations, enforcement and defense of the transactions
      contemplated by this Agreement shall be commenced exclusively in the state
      and
      federal courts sitting in the County and State of New
      York. Each party hereto hereby irrevocably submits to the exclusive jurisdiction
      of the state and federal courts sitting in the County and State of New York
      for
      the adjudication of any dispute hereunder or in connection herewith or with
      any
      transaction contemplated hereby or discussed herein, and hereby irrevocably
      waives, and agrees not to assert in any Proceeding, any claim that it is not
      personally subject to the jurisdiction of any such court, that such Proceeding
      is improper. Each party hereto hereby irrevocably waives personal service of
      process and consents to process being served in any such Proceeding by mailing
      a
      copy thereof via registered or certified mail or overnight delivery (with
      evidence of delivery) to such party at the address in effect for notices to
      him/it under this Agreement and agrees that such service shall constitute good
      and sufficient service of process and notice thereof. Nothing contained herein
      shall be deemed to limit in any way any right to serve process in any manner
      permitted by law. Each party hereto hereby irrevocably waives, to the fullest
      extent permitted by applicable law, any and all right to trial by jury in any
      legal proceeding arising out of or relating to this Agreement or the
      transactions contemplated hereby. If either party shall commence a Proceeding
      to
      enforce any provisions of this Agreement, the Purchase Agreement or any
      ancillary agreement, then the prevailing party in such Proceeding shall be
      reimbursed by the other party for its reasonable attorneys’ fees and other costs
      and expenses incurred with the investigation, preparation and prosecution of
      such Proceeding.




-11-




(k)  Cumulative
      Remedies .
      The
      remedies provided herein are cumulative and not exclusive of any remedies
      provided by law.




(l)  Severability .
      If any
      term, provision, covenant or restriction of this Agreement is held by a court
      of
      competent jurisdiction to be invalid, illegal, void or unenforceable, the
      remainder of the terms, provisions, covenants and restrictions set forth herein
      shall remain in full force and effect and shall in no way be affected, impaired
      or invalidated, and the parties hereto shall use their reasonable efforts to
      find and employ an alternative means to achieve the same or substantially the
      same result as that contemplated by such term, provision, covenant or
      restriction. It is hereby stipulated and declared to be the intention of the
      parties that they would have executed the remaining terms, provisions, covenants
      and restrictions without including any of such that may be hereafter declared
      invalid, illegal, void or unenforceable.




(m)  Headings .
      The
      headings in this Agreement are for convenience of reference only and shall
      not
      limit or otherwise affect the meaning hereof.




IN
      WITNESS WHEREOF, the parties have executed this Registration Rights Agreement
      as
      of the date first written above.




**PROTEIN
                POLYMER**
              **TECHNOLOGIES****,
                INC.**
            
            
            **TAG
                VIRGIN ISLANDS, INC.**
              as
                agent for the PurchasersBy:/s/William
                N. Plamondon, III
            
            
            By:/s/James TagliaferriName:William
                N. Plamondon, III
            
            
            Name:James
                TagliaferriTitle:President
            
            
            Title:President






-12-


**EXHIBIT
      A**




[date]





[Transfer
                Agent]
              [Address]





Re:
            Protein
                Polymer Technologies,
                Inc. Registration Statement on FormS-1




Ladies
      and Gentlemen:




As
      counsel toProtein
      Polymer Technologies,
      Inc., a
      Delaware corporation (the “Company”), we have been requested to render our
      opinion to you in connection with the resale by the individuals or entitles
      listed on Schedule B attached hereto (the “Selling Stockholders”), of an
      aggregate of [amount] shares (the “Shares”) of the Company’s Common
      Stock.




A
      Registration Statement on Form S-1 or S-3 under the Securities Act of 1933(the
      “Act”), with respect to the resale of the Shares was declared effective by the
      Securities and Exchange Commission on [date]. Enclosed is the Prospectus dated
      [date]. We understand that the Shares are to be offered and sold in the manner
      described in the Prospectus.




Based
      upon the foregoing, upon request by the Selling Stockholders at any time while
      the registration statement remains effective, it is our opinion that the Shares
      have been registered for resale under the Act and new certificates evidencing
      the Shares upon their transfer or re-registration by the Selling Stockholders
      may be issued without restrictive legend. We will advise you if the registration
      statement is not available or effective at any point in the future.




Very
              truly yours,[Company
              counsel]




-13-