Document:

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                                                                    EXHIBIT 10.4

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                            SHARE PURCHASE AGREEMENT

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BETWEEN THE UNDERSIGNED:

       MARIE-PAULE LEROY-LANDERCY,
       residing 5, ter rue Casteja, 92100 Boulogne Billancourt, France,

       hereinafter referred to as "MPLL",

                                                              OF THE FIRST PART,

AND:

       BIOSEPRA INC.,
       a company organized under the laws of Delaware, having its registered
       office at 111 Locke Drive, Marlborough, MA 01752, United States of
       America,

       represented by Mr. Jean-Marie Vogel,

       hereinafter referred to as "BIOSEPRA",

                                                             OF THE SECOND PART.

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RECITALS:

A)       At the date hereof MPLL holds 9,940 shares representing 99.4% of the
         capital and voting rights in Biosphere Medical SA (the "Company"), a
         French SOCIETE ANONYME with a share capital of FF. 1.000.000,
         divided into 10,000 shares of FF. 100 each, having its registered
         office at Zone Industrielle de Louvres, Rue de la Briqueterie, 95380
         Louvres, registered at the Registre du Commerce et des Societes of
         Pontoise under no. 418.584.033 and guarantees that she will hold 100%
         of the shares in the Company on the Closing Date.

         BIOSEPRA has informed MPLL of its Interest in acquiring 51% of the
         shares of the Company hereafter referred to as the "Shares".

         MPLL has informed BIOSEPRA of its desire to sell the 51% shares
         BIOSEPRA is interested in acquiring.

         The Parties have agreed to enter into this Agreement in order to define
         the terms and conditions of their respective undertakings for the
         purposes of and in connection with the sale and acquisition of the
         Shares.

B)       DEFINITIONS

         "Agreement" means the present document.

         "BIOSEPRA" means BIOSEPRA Inc, or any legal entity(ies) of the BIOSEPRA
         Group substituted by BIOSEPRA Inc. in accordance with the provisions of
         Article 1.1 hereinafter.

         "Closing Date" means the date fixed for the Transfer of the Shares
         under Article 1.2 hereof.

         "Company" means Biosphere Medical SA.

         "Confidential Information" means information concerning or relating to
         all or any of the following matters relating to or connected with the
         affairs of the Company details of which are not in the public domain:
         the intellectual property and any other property of the Company and/or
         the Subsidiaries in the nature of intellectual property or any other
         know-how, technical processes, customer, client and supplier lists,
         price lists, details of contractual arrangements and any other matters
         concerning the business affairs, or finances of the Company or clients
         or customers or other persons having dealings with the Company (however
         stored).

         "MPLL" means Marie-Paule Leroy-Landercy.

         "Option" means the promise to sell the Remaining Shares granted to
         BIOSEPRA by MPLL stipulated in Article 2.5.

         "Parties" means BIOSEPRA and MPLL.

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         "Price" means the price mentioned in Article 1.3.1 hereafter.

         "Promise" means the promise to buy the Remaining Shares granted by
         BIOSEPRA to MPLL stipulated in article 2.6.

         "Related Securities" means the securities defined in clause 2.5.4
         hereafter.

         "Remaining Shares" means the shares of the Company held by MPLL after
         the Closing Date as defined in article 2.5 hereafter.

         "Sales of the Company" means aggregate sales of Biosphere, increased by
         any additional sales of Specialities as defined in the exclusive
         license contract mentioned in article 1.3.1 hereafter realized
         worldwide by BIOSEPRA and/or its affiliates, except for intra-group
         sales.

         "Shares" means the 5,100 shares of a par value of FF. 100 each in the
         capital of the Company representing 51 % of the share capital which
         MPLL has agreed to transfer to the BIOSEPRA under the Agreement.

         The Exhibits form part of the Agreement.

         The headings in this Agreement are for ease of reference only and shall
         not affect the construction or interpretation of this Agreement.

         References to persons shall include bodies corporate, unincorporated,
         associations and partnerships.

         References to the parties hereto include their respective successors in
         title assigns and legal personal representatives.

ARTICLE 1: SALE

1.1      SALE OF THE SHARES

         MPLL sells to BIOSEPRA and BIOSEPRA acquires from MPLL a number of
         shares in the Company representing 51% of its capital and voting rights
         under the terms and conditions set forth hereinafter.

         Any legal entity(ies) of the BIOSEPRA Group may be substituted by
         BIOSEPRA Inc. in the benefit of this Agreement as the purchaser of the
         Shares, in whole or in part, by giving notice thereof to MPLL by
         registered letter with an acknowledgment of receipt, or any equivalent
         means, at the latest one day before the Closing Date, as defined in
         Article 1.2 hereinafter. In the above mentioned notice, the buyer will
         guarantee the commitments resulting from the Agreement of all
         substituted persons.

         The Shares are on the Closing Date, free of any pledge or other
         security interest, option or other right in favor of third parties.

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1.2      TRANSFER OF THE SHARES

         The transfer of the Shares shall take place as of this date hereinafter
         referred to as the "Closing Date". The transfer of the shares shall
         occur at the latest 60 days as of the date of signature of the present
         Agreement.

1.3      PRICE OF THE SHARES

1.3.1    The Parties have agreed that the Price for the Shares shall be equal to
         FF. 1 (one French franc). The Price is justified by the fact that,
         amongst others, at the Closing Date, BIOSEPRA will grant to the Company
         an exclusive license pertaining to patents and technology relating to
         embolization microbeads and will transfer its technology in connection
         with vascular applications which shall strengthen substantially the
         activity of the Company, and the Company will benefit from synergies
         with BIOSEPRA group.

1.3.2    On the Closing Date BIOSEPRA shall pay to MPLL the Price (by means of a
         bank check or by wire transfer).

1.4      DOCUMENTS SUPPLIED ON THE CLOSING DATE

         MPLL delivers the following, documents to BIOSEPRA on the Closing Date:

         (i)      "Ordre de mouvement" (stock transfers) relating to 51% of the
                  Shares and "Ordres de mouvement" with respect to minority
                  shareholders, i.e. Mr. Aime Poirier, Mrs. Claire Ardouvin,
                  Mrs. Maryvonne Fallavier, Mrs. Colette Bouillette, Mrs. Herve
                  and Mr. Angeloglou

         (ii)     the minutes of the general shareholders meetings of the
                  Company amending the Articles to create two classes A and B of
                  shares of the Company and appointing Messrs. Jean-Marie Vogel,
                  Egisto Boschetti and Aime Poirier as directors;

         (iii)    the resignation letters from Mr. Aime Poirier, Mrs.
                  Marie-Paule Leroy-Landercy, Mrs. Claire Ardouvin and Mrs.
                  Maryvonne Fallavier, containing their resignations from their
                  positions as directors of the Company and stating that the
                  Company does not owe them any amount for any reason
                  whatsoever;

         (iv)     the statutory auditors' letters of resignation from the
                  Company;

         (v)      the minutes of the meeting of the board of directors of the
                  Company at which the intended sale by MPLL to BIOSEPRA was
                  approved;

         (vi)     the minutes of the meeting of the board of directors of the
                  Company appointing Mr. Jean-Marie Vogel as chairman of the
                  board, and MPLL as "DIRECTEUR GENERAL NON ADMINISTRATEUR" and
                  as salaried Technology Manager (DIRECTEUR DES TECHNOLOGIES).

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         The following, agreements are also signed on the Closing Date:

         (i)      an exclusive license agreement between the Company and
                  BIOSEPRA relating to all of BIOSEPRA's patents and technology
                  relating to embolization microbeads, substantially in
                  accordance with the terms of the draft attached hereto in
                  EXHIBIT 1.4 duly signed;

         (ii)     the labor contract between MPLL and the Company in accordance
                  with the terms of the draft attached hereto in EXHIBIT 1.4
                  duly signed.

ARTICLE 2: COVENANTS OF MPLL AND BIOSEPRA

2.1      MPLL undertakes to and covenants with BIOSEPRA that she will not at any
         time after the date of this Agreement:

         (i)      disclose or divulge to any person other than to officers or
                  employees of any BIOSEPRA's group member whose function it is
                  to know the same or to any of their professional advisers any
                  Confidential Information which may be within or have come to
                  its knowledge and it shall use its best endeavors to prevent
                  the publication or disclosure of any Confidential Information;

         (ii)     do or say anything which is likely or intended to damage the
                  goodwill or reputation of the Company or use the event of the
                  Sale of the Company to encourage any person to cease to do
                  business with the Company on substantially equivalent terms to
                  those previously offered or lead any person not to engage in
                  business with the Company.

2.2      Unless demanded by law or relevant administrative authority or to
         enforce its performance and/or sue for damages a defaulting party, it
         is understood that no revelation or communication of any of the
         provisions of this Agreement may be made by one of the Parties without
         the written consent of the other.

2.3      MPLL hereby undertakes to and covenants with BIOSEPRA that she will not
         as long as she remains a shareholder of the Company and for a period
         starting the date she sells her last Remaining Share(s) in the Company
         and lasting five years from that date, either on its own behalf or
         jointly with or as manager, adviser, consultant or agent for any other
         person directly or indirectly, in the field of embolization:

         (i)      approach, canvass, solicit or otherwise act with a view to
                  enticing away from or seeking in competition with any business
                  of the Company as carried on by the Company at any time the
                  custom of any person who has at any time been a customer of
                  the Company and during such period she shall not use her
                  knowledge of or influence over any such customer to or for her
                  own benefit or the benefit of any other person carrying on
                  business in competition with the Company or otherwise use its
                  knowledge of or influence over any such customer to the
                  detriment of the Company;

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         (ii)     be engaged, concerned or interested howsoever in carrying on
                  any business worldwide if such business is in competition with
                  the business carried on at any time by the Company.

2.4      MPLL hereby undertakes to and covenants with BIOSEPRA that she will not
         as long as she remains a shareholder of the Company and for a period
         starting the date she sells her last Remaining Share(s) in the Company
         and lasting five years from that date either on her own behalf or
         jointly with or as manager adviser consultant or agent for any other
         person directly or indirectly approach, canvass, solicit, engage or
         employ or otherwise endeavor to entice away any person who shall be or
         shall have been an employee officer or manager of the Company at any
         time from and after the date of this Agreement.

2.5      PROMISE TO SELL THE REMAINING SHARES

         MPLL holds just after the Closing Date 49% of the share capital of the
         Company i.e.: 4,900 shares, hereafter referred to as the "Remaining
         Shares".

2.5.1    MPLL hereby irrevocably promises to sell to BIOSEPRA all the Remaining
         Shares (hereafter the "Option") at a price per share equal to the Sales
         of the Company over the last period of 12 months ending at the end of
         the month preceding the one during which the Option will be exercised
         by BIOSEPRA, divided by the total number of shares in the Company at
         that time, pursuant to the following schedule:

         a)       BIOSEPRA may exercise the Option granted to it hereabove by
                  MPLL on 70% of the Remaining Shares from the Closing Date
                  until the fifth anniversary of the Closing Date, i.e.,:
                  December 31, 2003.

         b)       BIOSEPRA may exercise the Option on 30% of the Remaining
                  Shares still held by MPLL from December 31, 2003 until
                  December 31, 2004.

         In any case, the minimum price to be paid by BIOSEPRA for the total
         Remaining Shares should not be less than 49 % of FF. 12,000,000 (twelve
         million French francs).

         BIOSEPRA may substitute to itself in the benefit of the Option any
         affiliated company.

2.5.2    If the Option is exercised by BIOSEPRA, or any substituted company, the
         Remaining Shares will be transferred free of any liens, charges,
         privileges, guarantees, options or other rights in favor of third
         parties.

         MPLL irrevocably undertakes neither to transfer the Remaining Shares to
         any third party before December 31, 2004, nor, for the same duration,
         to grant to any third party a right of any nature whatsoever on the
         Remaining Shares, such as, but not limited to, option, lien,
         guarantee...

         If the Option is exercised, the transfer of the Remaining Shares will
         take place at the latest the 15th day following such exercise.

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2.5.3    The Option stipulated in article 2.5 hereby and all its provisions will
         also apply to:

         (i)      the shares, voting certificates and certificates of
                  investment;

         (ii)     the warrants, bonds, combined securities, options, rights and
                  other securities or titles which may give access, immediately
                  or in the future, directly or indirectly, whatever be the
                  importance or form of such access, to the capital, the profits
                  or to the votes at general meetings of the shareholders of the
                  Company.

         All such items mentioned in (i) and (ii) being herein called the
         "Related Securities", which at the date of exercise of the Option MPLL
         may as a result of the Remaining Shares hold (or in which, at the date
         of exercise, she may have rights to), in the Company or any other
         company which might succeed to the Company by reason of any
         restructuring, merger, modification of the capital, etc., without
         modification to the price for the Remaining Shares mentioned in clause
         2.5.1 above, except in the case where such Related Securities will have
         been (or would be) granted to MPLL in consideration of contributions in
         cash or in kind or by way of setting off of credit in which case, the
         said price will be increased by the amounts actually contributed or
         paid through setting off by MPLL.

2.6      If after December 31, 2003, MPLL still holds the totality or part of
         the Remaining Shares and is still an employee of the Company or of any
         of BIOSEPRA's affiliated companies, or has been dismissed for a cause
         other than "FAUTE GRAVE" or "FAUTE LOURDE", or is deceased, she or her
         successor as the case may be will benefit from BIOSEPRA of a promise
         from the latter to purchase the Remaining Shares still held by her,
         (hereafter the "Promise").

2.6.1    BIOSEPRA hereby irrevocably promises to buy from MPLL all the Remaining
         Shares still held by MPLL.

         MPLL may exercise the Promise granted to it hereabove by BIOSEPRA from
         December 31, 2003 until December 31, 2004.

2.6.2    If MPLL exercises the Promise set forth in article 2.6 hereabove,
         BIOSEPRA shall pay the Remaining Shares -or the prorata of the
         remaining, shares still held thereof- at a price per share equal to the
         Sales of the Company over the last period of 9 months ending at the end
         of the month preceding the transfer of the Remaining Shares, divided by
         the total number of shares in the Company at that time. In any case,
         the minimum price paid by BIOSEPRA to MPLL for the Remaining Shares
         still held by MPLL after December 31, 2003 shall not be less than 49%
         of FF. 6,000,000 (or the prorata of such amount if BIOSEPRA has
         exercised the Option on part of the Remaining Shares it being
         understood that for the calculation of the prorata all the Remaining
         Shares represents 49%).

         BIOSEPRA may substitute to itself in the exercise of the Promise any
         affiliated company. In case of substitution, BIOSEPRA will guarantee
         the commitments resulting from the Promise of all substituted persons.

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2.6.3    If the Promise is exercised by MPLL, the Remaining Shares will be
         transferred free of any liens, charges, privileges, guarantees, options
         or other rights in favor of third parties, and the transfer of the
         Remaining Shares will take place at the latest the 15th day following
         such exercise.

         The Promise can be exercised by MPLL only for all the Remaining Shares,
         and not part of them.

2.6.4    The Promise stipulated in article 2.6 hereby and all its provisions
         will also, mutatis mutandis, apply to the Related Securities mentioned
         in clause 2.5.4 hereabove, under the same terms and conditions save for
         the reference to the price which will be the one stipulated in clause
         2.6.2.

2.6.5    BIOSEPRA undertakes to cause the shareholders meeting of the Company to
         appoint MPLL as a director ("ADMINISTRATEUR") at the board of the
         latter as soon as legally possible after the Closing Date.

2.6.6    BIOSEPRA and MPLL will vote, at a shareholders meeting to be held as of
         the Closing Date, for the modification of the by-laws of the Company to
         create in particular two classes A and B of shares in compliance with
         the terms and conditions set forth in the Shareholders Agreement
         attached in Exhibit 2.6.7.

2.6.7    BIOSEPRA and MPLL shall sign a shareholders agreement in compliance
         with Exhibit 2.6.7 (hereafter the "Shareholders Agreement"). The
         Shareholders Agreement shall provide for the right for MPLL and
         BIOSEPRA to appoint directors in proportion to their respective
         percentage in the total share capital of the Company.

         The Shareholders Agreement shall also grant to the directors appointed
         by MPLL a right of veto of the following decisions :

         -    any change to the exclusive license contract mentioned in
              article 1.3.1 hereto. However such contract may be terminated in
              the event that the amount or amounts for which MPLL may be liable
              for under this Agreement exceed the sum of FF. 100,000.

         -    change of the head office of the Company.

         -    guarantees ("AVALS" and "CAUTIONS") for an amount exceeding 1
              million French francs, granted by the Company to the benefit of
              companies other than the Company's affiliates.

         The Shareholders Agreement shall be automatically terminated if and
         when the Company is listed at the French "NOUVEAU MARCHE". The
         Shareholders Agreement shall also be automatically terminated if and
         when BIOSEPRA exercises the Option on 70% of the Remaining Shares
         provided for in article 2.5.1 a) hereto.

2.6.8    BIOSEPRA shall irrevocably assign, worldwide and free of charge, all
         its rights to its technology and patent portfolio for vascular
         applications, including its recent patent application for spherical PVA
         beads.

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ARTICLE 3: REPRESENTATIONS AND WARRANTIES OF MPLL

3.1      SCOPE OF THE REPRESENTATIONS AND WARRANTIES

         BIOSEPRA buys the Shares under the condition that MPLL makes the
         representations and grants the warranties contained in the present
         article 3.

         The warranties and representations herein are stipulated for the
         benefit of BIOSEPRA and they will remain valid for the duration
         stipulated in this Agreement, even if BIOSEPRA resells some or all of
         the Shares. MPLL hereby represents and warrants that they are true and
         accurate on the date of this Agreement.

         So far as MPLL is aware after careful consideration there are no facts
         or considerations which are not disclosed in the Agreement and its
         Exhibits which by their omission would or might:

         (i)      affect the import of the information contained therein; or

         (ii)     make any statement therein false or misleading; or

         (iii)    invalidate or qualify any assumption expressed to be made in
                  support of any statement therein; or

         (iv)     be material for disclosure either to BIOSEPRA or to a
                  potential buyer of the Shares being information which
                  discloses circumstances whereby the Company is or is likely to
                  be affected.

3.2      REPRESENTATIONS AND WARRANTIES

3.2.1    ACCURACY AND RELEVANCE OF THE INFORMATION GIVEN TO BIOSEPRA

         All information represented in the Exhibits and all other information
         contained in the present Agreement concerning the Company is true and
         accurate.

         No representation or warranty contained in this Agreement and its
         Exhibits, which are an integral part thereof contains any untrue
         statement or omits a fact necessary to make such representation or
         warranty not misleading. MPLL has no knowledge of facts or
         circumstances rendering any such information false, untrue or
         misleading.

3.2.2    CAPACITY AND POWER OF MPLL

         MPLL has all necessary power and authority to conclude and to execute
         the Agreement. The Agreement represents a valid and binding obligation
         of MPLL in accordance with its terms and does not violate or result in
         a breach or default under any agreement or commitment to which MPLL or
         the Company is a party or which is binding upon it.

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         Neither the Company nor MPLL is a party to, subject to, or bound by any
         mortgage, deed of trust, indenture or other instrument or agreement or
         by any judgment, order, writ, injunction, or decree of any court or
         governmental body, and there is no provision in the Company's
         organizational documents or, to the knowledge of MPLL, in any statutes,
         rule or regulation, that would prevent or materially impair (i) the
         execution, delivery or performance of this Agreement, or the agreements
         contemplated hereby, (ii) BIOSEPRA's ability to exercise rights as a
         controlling or majority shareholder of the Company, or (iii) the
         carrying on or the right to carry on the business of the Company as it
         is now constituted.

3.2.3    INCORPORATION OF THE COMPANY

         The Company has been duly incorporated and properly formed, and its
         articles of incorporation, as well as the manner in which it is
         operating, are in accordance with all applicable laws and regulations.

3.2.4    SHARES AND PARTICIPATIONS OF THE COMPANY

         All the shares of the Company have been issued in accordance with
         applicable laws and regulations and are entirely paid-up and free of
         any liens, charges, privileges, guarantees, options or other rights in
         favor of third parties.

         There exists no contract or commitment of any nature, whether signed or
         unsigned, with a view to allocating or issuing shares, or giving rise
         to any right of any person to buy or preempt, in whole or in part, the
         shares of the Company.

         The Company does not own, directly or indirectly, any holding in any
         legal entity, grouping or partnership of whatever kind, including any
         "SOCIETE DE PERSONNES", "SOCIETE CIVILE IMMOBILIERE", "G.I.E.", SOCIETE
         DE PARTICIPATION", or in which the liability of the members or partners
         is not limited to their ownership interest.

         The Company has issued no priority shares, preferred shares, bonds
         convertible into shares, exchangeable against shares or giving rights
         to subscribe to shares. More generally, the Company has issued no
         securities giving rights, by conversion, exchange, warrant,
         reimbursement or in any other manner, to the distribution, immediately
         or in due course, of shares for which purpose are or will be issued in
         representation of amount of shares in the capital of the Company. No
         issuing of any securities of the type described hereabove is currently
         in progress.

3.2.5    TRANSFER AND OWNERSHIP OF THE SHARES

         The Shares are on the Closing Date owned by MPLL, at its free disposal
         without any restriction and represent 51% of the authorized legal
         capital of the Company.

         BIOSEPRA acknowledges that the transfer of the Shares may, if requested
         by Guerbet SA, entail the early repayment by the Company of the loan
         amounting to 3 million French francs granted by Guerbet SA by contract
         dated April 29, 1998, which repayment is to be made within 6 months
         after the change of control under the provisions of article 8 of the
         loan agreement.

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         All the procedures relating to the transfer of the Shares at the
         Closing Date which are necessary, in order that the transfer can take
         place in compliance with all applicable laws and regulations at the
         Closing Date, have been duly performed.

3.2.6    STATUTORY BOOKS

         To the best of MPLL's knowledge:

         -    all accounting books, statutory books and files required by
              applicable laws and regulations are maintained by and in the
              possession of the Company, and contain information which is true
              and correct and duly recorded in accordance with applicable
              regulations and laws.

         -    all documents evidencing the ownership of the assets of the
              Company and signed copies of all contracts entered into by it
              which are currently in force, are essential to its activity, and
              should be in their possession, are in the possession of the
              Company.

3.2.7    OPTIONS, MORTGAGES AND OTHER GUARANTEES

         There exists no option, mortgage, lien, pledge, or any other form of
         guarantee or privilege in favor of third parties on all or any part of
         the assets of the Company. No contract or commitment to grant any of
         these rights or guarantees has been concluded. Neither the Company nor
         its employees or representatives have received any claim from any
         person claiming to benefit from any of the rights or guarantees
         mentioned above.

3.2.8    COMPLIANCE WITH LAWS AND REGULATIONS

         To the best of MPLL's knowledge:

         -    the Company has all material permits and authorizations necessary
              for the ownership of its assets and for the conduct of its current
              business. The Company has complied with all material laws,
              regulations and customs applicable to such business, in particular
              all regulations relating to labor regulations, environment
              regulations, as well as all conditions in respect of the required
              permits and authorizations.

         -    the Company is not bound to arrange measures which would require
              new investments in order to comply with any of these laws or
              regulations.

         -    there exists no event that might bring about the revocation or
              suspension of any permits or authorizations held by the Company or
              that might involve its liability or that of its directors or
              employees, in particular by reason of the violation of regulations
              relating to environmental law and labor law.

         -    the transfer of ownership of the Shares to BIOSEPRA will not bring
              about the revocation or suspension of any permit or authorization
              necessary for the conduct of the business of the Company.

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         -    all information transmitted to governmental authorities are true
              and accurate.

3.2.9    AGREEMENTS

         to the best of MPLL's knowledge:

         -    the Company is not party to any one or more agreements or
              commitments which are manifestly of an unusual nature and/or
              duration or otherwise outside the normal course of business and
              more specifically the Company is not subject to any
              non-competition commitment or restriction from doing business
              which it is legally capable of carrying on.

         -    there exists no contract or agreement entered into by the Company,
              which includes a provision enabling the other contracting party to
              terminate it (or to demand modification of the contractual
              provisions) as a result of a change in the ownership of the
              Company.

3.2.10   LOANS AND OTHERS

         Complete and accurate information (in particular the amount, duration,
         security...) relating to all loans, credit contracts, overdraft
         agreements or other banking facilities of the Company in existence are
         contained in EXHIBIT 3.2.10.

3.2.11   GUARANTIES

         No security guarantee, sponsorship or comfort letter of any nature
         given or incurred by the Company is in effect on the Closing Date.

3.2.12   PROFIT-SHARING AGREEMENT

         The Company is not a party or has not agreed to be a party to any
         agreement giving any third party any right to share in whole or in part
         in its profits.

3.2.13   INSOLVENCY

         No receiver ("ADMINISTRATEUR JUDICIAIRE") has been appointed to manage
         all or any part of the assets or the business of the Company.

         No request or declaration has been made with a view to the judicial
         reorganization or judicial liquidation of the Company or with a view to
         the dissolution and early liquidation of the Company.

         The Company has not ceased making payments to creditors, is not
         insolvent or unable to pay its debts.

3.2.14   LITIGATION

         To the best of MPLL's knowledge, the Company is not engaged directly,
         or through employees or/and directors, actual or former, in any
         judicial criminal, administrative or arbitral proceedings, as plaintiff
         or defendant, including by way of counterclaim.

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         There does not exist to MPLL's knowledge, after due inquiry in that
         respect, any fact that would give rise to any proceeding against the
         Company or against one of its directors, employees, or former directors
         or employees for which the Company would be liable.

         In particular, the Company is not a defendant to, and to MPLL's
         knowledge is not threatened with, any lawsuit brought by customers or
         third parties.

         Furthermore, to MPLL's knowledge there has been no court or
         administrative decision or order, and no time limit given by a
         professional organization or supervisory authority, imposing on the
         Company, an obligation which might in the future have unfavorable
         consequences on the normal course of its business.

3.2.15   EMPLOYEES, REPRESENTATIVES OF THE COMPANY

         The current employees of the Company, along with an indication of their
         age and seniority, are listed in EXHIBIT 3.2.15. No binding promise to
         hire any person has been granted by the Company and the Company has not
         granted any loans to its employees.

3.2.16   REAL AND PERSONAL PROPERTY

         The Company owns no real property. All personal property necessary to
         its current business, except the property subject to the leasing
         contracts which are listed in EXHIBIT 3.2.16, is fully owned by the
         Company.

3.2.17   INTELLECTUAL PROPERTY

         the Company owns or is entitled to use all patents and trademarks,
         tradenames, processes, software, company name and more generally all
         intellectual property rights, if any, that it uses the course of its
         business, except what is mentioned in EXHIBIT 3.2.18.

         None of these rights has been transferred in any way to any third party
         or infringes the rights of any third party. The documentation
         pertaining to such rights is contained in EXHIBIT 3.2.18.

3.2.19   INSURANCE

         To the best of MPLL's knowledge:

         -    the Company is insured by policies in force, for which all
              premiums have been paid when due and which cover under normal
              conditions the risks regularly incurred by companies operating a
              business similar to those of the Company. The Company has not
              committed or omitted any act which might render null or
              inoperative such insurance policies or which might bring about
              their cancellation.

         -    there exists at present no lawsuit involving the application of
              the Company's insurance policies, and no event has occurred which
              might bring about such a lawsuit.

<PAGE>

         A description of the insurance contracts concluded by the Company is
         contained in EXHIBIT 3.2.19.

3.2.21   TAX AND OTHER RETURNS

         To the best of MPLL's knowledge, the Company has regularly filed all
         required tax, Social Security and all administrative returns and has
         paid or provided for all taxes, duties, levies and Social Security
         charges, including any interest, fines or penalties relating thereto.

         There is no current dispute with any government authority concerning
         taxes, customs or Social Security charges and, to MPLL's knowledge,
         there is no reason to believe any such dispute might arise.

3.3      INDEMNIFICATION

         a)       MPLL undertakes to pay to BIOSEPRA or to the Company, at
                  BIOSEPRA's option, a sum, covering all harmful consequences
                  duly suffered for BIOSEPRA and/or the Company as a result of
                  any failure to comply with, any omission or inaccuracy of any
                  one of the representations and covenants contained in this
                  Agreement.

         b)       It is understood that the amount of any sum due from MPLL to
                  BIOSEPRA and/or the Company, as the case may be, under clause
                  3.3 a) of this Agreement will be reduced by (i) the amount of
                  any insurance payment actually received by BIOSEPRA or the
                  Company in relation to any event giving rise to a claim by
                  BIOSEPRA hereunder (ii) elements likely to increase
                  liabilities and assets.

         c)       Any amount or amounts that MPLL may be liable to pay pursuant
                  to this Agreement shall not exceed the sum of FF. 49% of
                  FF. 6,000,000 except as regards the representations and
                  guarantees given by MPLL in articles 3.2.2., 3.2.3, 3.2.4 and
                  3.2.5.

                  Furthermore, the amount or amounts for which MPLL may be
                  liable under this Agreement shall only be payable if such
                  amount or amounts have reached the aggregate amount of FF.
                  100,000. This aggregate amount may be only subtracted once
                  from the amounts due to BIOSEPRA

         d)       All grounds likely to result in a call on the guarantee set
                  forth by this Agreement shall be notified by BIOSEPRA within
                  30 days from the moment BIOSEPRA is aware thereof. MPLL shall
                  have 21 days, either to acknowledge its acceptance of
                  BIOSEPRA's claim, or to communicate its disagreement. The lack
                  of response in this period of time shall be considered as an
                  acceptance of BIOSEPRA's claim by MPLL.

<PAGE>

         e)       BIOSEPRA, acting on behalf of the Company, shall not enter
                  into a settlement agreement on any matters likely to entail
                  MPLLs' liability under this guarantee, without the approval of
                  MPLL, which approval shall not be unreasonably withheld.

                  Such approval shall be deemed to have been obtained if MPLL
                  fails to notify its opposition to the planned settlement
                  agreement within more than 21 days of receiving a registered
                  mail in which BIOSEPRA shall have given notice of its
                  intention so to proceed on the basis of explicit information.

3.4      DURATION OF THE GUARANTEE

         All demands for payment (which can only be valued as a provisional
         figure under this indemnification) under the Agreement in regard to
         matters of a tax, administrative, Social Security nature or pertaining
         to clauses 3.2.2 and 3.2.5 must be made by BIOSEPRA, even if only
         provisionally, before the expiration of a period equal to the
         applicable limitations provided by law plus three (3) months and, in
         regard to any other matter, before January 1st, 2004.

3.5      PAYMENT

         The payment of any sum due by MPLL in application of article 3 of the
         Agreement shall be made, by means of an actual payment by MPLL to
         BIOSEPRA, up to the amount of FF. 500,000 and exclusively by means of
         set-off against any sum that BIOSEPRA owes to MPLL, in particular as
         payment of the price of the Remaining Shares, with respect to any sum
         due by MPLL exceeding the above mentioned FF. 500,000 threshold.

         The payment of any sum due by MPLL to BIOSEPRA and/or the Company under
         this Agreement (either pursuant to MPLL's acceptance of BIOSEPRA's
         claim or arbitrator's award), subject to the provisions of the above
         paragraph, shall be made within thirty (30) days of the payment by the
         Company of any sum covered by this indemnification, supported by
         appropriate justifying documents.

ARTICLE 4: MISCELLANEOUS PROVISIONS

4.1      WHOLE AGREEMENT

         This Agreement constitutes the whole and unique agreement of the
         parties on the matters it relates to. It replaces and cancels therefore
         any prior contract or agreement, whether written or oral between the
         parties on matters covered by this Agreement. This Agreement shall be
         modified only in writing with the signature of both parties.

<PAGE>

4.2      COSTS AND FEES

         Each of the Parties shall bear, without entitlement to a refund from
         the other, the costs incurred by it in connection with the preparation
         and conclusion of this Agreement, including all expenses, fees and
         disbursements for legal advice, auditors and other advisers instructed
         by either of the Parties.

ARTICLE 5: GOVERNING LAW AND DISPUTES

Clause 2.2 of the Agreement shall not apply for the performance of article 5.

5.1      GOVERNING LAW

         The Agreement is governed by, and shall be construed in accordance
         with, French law.

5.2      DISPUTES

         The parties agree to submit any and all disputes arising with respect
         to the validity, interpretation or performance of this agreement to the
         exclusive jurisdiction of Paris Commercial Court ("Tribunal de Commerce
         de Paris") due to the commercial nature of the Agreement.

ARTICLE 6: NOTICES

All notices under this Agreement shall be sent by registered mail, return
receipt requested, and shall be deemed sent on the date of receipt or on the
date of mailing if preceded by transmission of the text of such notice by telex
or fax. Such notices shall be sent, until changed by notice given as indicated
above, to the following addresses:

         -   If MPLL to:         Marie Paule Leroy-Landercy at her address
                                 mentioned on the first page of this Agreement

         -   If BIOSEPRA to:     BIOSEPRA Inc. at its head office mentioned on
                                 the first page of this Agreement

                                 Attention: Jean-Marie Vogel

                                                    Done in Paris
                                                    On December 31st, 1998
                                                    In 2 originals

/S/ MARIE-PAUL LEROY LANDERCY                          /S/ JEAN-MARIE VOGEL
-----------------------------                       ----------------------------
         for MPLL                                          for BIOSEPRA<PAGE>

                                                                    Exhibit 10.5

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

--------------------------------------------------------------------------------
                            JOINT OWNERSHIP CONTRACT
--------------------------------------------------------------------------------

BETWEEN THE UNDERSIGNED

         1) BIOSEPRA S.A., Corporation with headquarters at 35 Avenue Jean
Jaures 92395 VILLENEUVE LA GARENNE, represented for the purposes of this
document by its Chief Executive Officer Jean-Marie Vogel and its Executive
Director, Therese Bourdy, hereinafter referred to as "BIOSEPRA."

AND

         2) L'ASSISTANCE PUBLIQUE-HOPITAUX DE PARIS, Public Institution with
headquarters at 3 Avenue Victoria 75004 Paris, RP, represented for the purposes
of this contract, by delegation of its Executive Director, by Dominique Laurent,
Director of Medical Policy, hereinafter referred to as "AP-HP."

IT HAS BEEN STATED AS FOLLOWS:

The Angioma Group of the Therapeutic Neuroradiology and Angiography Service of
the Hopital Lariboisiere ("The Angioma Group") has been studying the use of
particle embolization agents for several years.

In the context of its experience, the Angioma Group developed the idea of using
microspheres initially designed for cell cultures not only to totally block
blood flow due to their shape and size, but also to cause the vascular lumen to
be occluded by cells that can proliferate on the microspheres, promoting
adhesion and immobilization, and resulting in satisfactory vascular occlusion.

BIOSEPRA (formerly IBF, then SEPRACOR), has developed and sold microspheres
designed for cell cultures, which were composed of a spherical core coated with
a chemotactic agent. One example is MICARCEL G composed of a patented
reticulated synthetic polymer - Tricasryl -coated with denatured collagen. These
microspheres constitute the basic embolization products covered by this
contract.

BIOSEPRA possesses substantial know-how in the area of the design of various
types of chemical microspheres, and considerable experience in the modification
of these materials in order to imbue them with specific properties.

Due to their complementary experience, the two parties decided to collaborate
for the development of microspheres adapted to embolization, and signed an
agreement on 7 June 1991 (contract number 90625300). This contract was extended
on 7 April 1993 through February 1994.

During the course of their technical collaboration, the parties developed
products according to predetermined specifications. As these products are the
joint property of the parties, the parties met to define the principles of the
applicable joint ownership arrangement, in accordance with the aforementioned
collaboration contract of 7 June 1991, and to define the conditions covering the
commercial use of these products.

                                                                               1
<PAGE>

NOW THEREFORE IT IS HEREBY AGREED AS FOLLOWS:

PRELIMINARY ARTICLE: DEFINITIONS

     1.  -CONTRACT PATENTS are defined as:

         - the application for French patent filed on 29 May 1991 in the names
of AP-HP and IBF under number 9106441, and the French patent "Microspheres
useful for therapeutic vascular occlusions and injectable solutions containing
the same" subsequently issued on 25 June 1995 under number 9106441.

         - all international extensions (patent applications and patents issued)
resulting from the above French patent, specifically in the context of the PCT
extension procedure undertaken on 20 May 1992 under number PCT/US 92/14625

     2.  -CONTRACT PRODUCTS are defined as the MICROSPHERES FOR EMBOLIZATION
covered by the CONTRACT PATENTS.

     3.  -CONTRACT SPECIALTIES are defined as any compound using the CONTRACT
PRODUCTS, and specifically any compound covered by the CONTRACT PATENTS.

     4.  -IMPROVEMENT is defined as any improvement or innovation, whether
patentable or not, arising from the CONTRACT PATENTS.

     5.  -CONTRACT SCOPE is defined as the utilization of the CONTRACT PRODUCTS
and the CONTRACT SPECIALTIES.

     6.  -SALES EXCLUDING TAXES are defined as the Net SALES, after deduction of
all commissions, rebates, balances for returned goods, insurance and
transportation expenses, taxes and duties.

     7.  -The PARTIES are defined as AP-HP and/or BIOSEPRA, signatories of this
contract.

     8.  -COMPANIES IN THE BIOSEPRA GROUP are defined as BIOSEPRA, BIOSEPRA Inc.
(Parent Company of BIOSEPRA), and in general any subsidiary or affiliate of
BIOSEPRA.

Subsidiary or Affiliate of BIOSEPRA is defined as any company, corporation,
partnership, joint venture, and/or firm which, either by capital or by
leadership, controls BIOSEPRA or is controlled by BIOSEPRA. For the purposes of
this paragraph, the term control specifically signifies:

         - in the case of entities formed as corporations, the direct or
indirect exercise of financial control of at least thirty-five percent (35%) of
the capital or shares entitling holder to vote in the election of the Board of
Directors.

         - in the case of entities not formed as corporations, the direct or
indirect control of at least thirty-five percent (35%) of the interest in the
realizable equity, with the power to direct the management and policies of the
entity not formed as a corporation.

                                                                               2
<PAGE>

                       ARTICLE 1: PURPOSE OF THE CONTRACT

The purpose of this contract is to define the principles of joint ownership
between BIOSEPRA and AP-HP for the CONTRACT PATENTS as well as the rights and
obligations of each of the PARTIES in the context of the commercial use of the
CONTRACT PRODUCTS AND SPECIALTIES.

                   ARTICLE 2: HISTORY OF THE JOINT OWNERSHIP

         2.1. The application for French patent number 9106441 recorded under
the title "Microspheres useful for therapeutic vascular occlusions and
injectable solutions containing the same" was filed jointly on 29 May 1991 in
the names of AP-HP and 103F.

Following an error attributable to SEPRACOR Inc., of which IBF had become a
subsidiary in July 1991, the international extension procedure for the CONTRACT
PATENTS was initiated in the name of SEPRACOR Inc. only.

Subsequently, SEPRACOR Inc. agreed to remedy this error and to transfer to its
French subsidiary BIOSEPRA and to AP-HP all of the rights related to the
international extensions of the CONTRACT PATENTS. BIOSEPRA undertook to ensure
compliance with this agreement and guaranteed AP-HP against any litigation or
loss that arose from or that may arise from said error.

The PARTIES did then and do now mutually acknowledge their status as exclusive
joint owners of the CONTRACT PATENTS, each party owning 50% of same, and each
party paying 50% of the filing, extension, and maintenance fees in effect in
accordance with article 3.2 of this contract.

         2.2. BIOSEPRA agrees to perform all formalities related to the
registration of the joint ownership mentioned in the paragraph above,
specifically recording the transfers on the various registers of the national
and supranational patent offices.

                     ARTICLE 3: MANAGING THE JOINT OWNERSHIP

         3.1. Managing the CONTRACT PATENTS

The PARTIES agree to charge BIOSEPRA with carrying out all actions required by
the national and supranational patent offices related to the management of the
CONTRACT PATENTS: writing and filing patent applications, follow up on
procedures for obtaining patents, payment of the various taxes and fees for the
filing, issuance, and maintaining of patents.

These actions shall be carried out in consultation with AP-HP, and BIOSEPRA
agrees to keep AP-HP fully informed of the various management actions required
and to obtain the consent of AP-HP whenever necessary.

         3.2. Expenses Associated with Rectifying the Joint Ownership of the
CONTRACT PATENTS

                                                                               3
<PAGE>

In order to take into account the provisions of article 2 of this contract, it
is hereby agreed that BIOSEPRA will cover the payment of all costs, taxes, fees,
and other sums related to the rectification of the joint ownership by the
PARTIES.

         3.3. Patent Filing and Maintenance Fees

All sums (specifically costs, taxes, fees, etc.) associated with the filing,
extension, and maintenance of the CONTRACT PATENTS shall be shared in equal
parts by the PARTIES, with the exception of sums relating to actions by internal
counsel or the employees of AP-HP, BIOSEPRA, and COMPANIES IN THE BIOSEPRA
GROUP.

It is however agreed that these costs shall be paid directly by BIOSEPRA, and
BIOSEPRA will deduct the amount from the royalties payable to AP-HP; in this
respect, it is understood that said deduction made annually by BIOSEPRA from the
amount of royalties payable to AP-HP for each year of use in question may not
exceed 50% (fifty percent) of the total amount of the royalties payables to
AP-HP for the year of use in question. (50% (fifty percent) of the total amount
of the royalties payables to AP-HP for the year of use in question is
hereinafter referred to as THE AMOUNT).

If, during a given year, the amounts to be deducted from the royalties payable
to AP-HP should exceed THE AMOUNT, the excess shall be charged to the royalties
payable to AP-HP for the following year, though the total amount to be deducted
may not exceed 50% of the amounts payable by BIOSEPRA for that following year.

Upon the expiration of this contract, all sums still owed by AP-HP under the
terms of article 3.3 shall be paid by AP-HP to BIOSEPRA.

BIOSEPRA shall in each case send AP-HP a copy of the invoices paid and
supporting documents for expenses incurred. If these documents do not contain
the necessary information, they will be accompanied by a detailed statement of
the various expense items.

         3.4. IMPROVEMENTS

                  (a) The PARTIES agree to keep each other mutually informed as
promptly as possible of any IMPROVEMENTS developed by them or by licensee
companies. The same applies in the case of any IMPROVEMENTS developed by third
parties that come to the attention of the PARTIES.

                  (b) The PARTIES agree that the IMPROVEMENTS developed
separately or jointly by them shall be their joint property with each party
owning 50%.

                  (c) The PARTIES agree to refrain from disclosing such
IMPROVEMENTS as long as they have not decided on the most appropriate exclusive
protection method for the IMPROVEMENTS in question. Once the decision is made,
the PARTIES shall determine by mutual agreement the period during which said
IMPROVEMENTS shall be kept confidential.

Barring express waiver of BIOSEPRA or AP-HP, applications for industrial
property titles filed in relation to the IMPROVEMENTS and any titles
subsequently issued shall be jointly owned in

                                                                               4
<PAGE>

equal shares by AP-HP and BIOSEPRA and shall be subject to the provisions of
this joint ownership contract.

The PARTIES agree to meet to negotiate in good faith and in the mutual interest
of the joint ownership covered in this contract any question or dispute
involving the IMPROVEMENTS. The same applies in the case of acquisition from a
third party of the rights necessary for the use of the IMPROVEMENTS developed by
said third party.

          ARTICLE 4: PRIMARY USE OF CONTRACT PRODUCTS AND SPECIALTIES

         4.1. BIOSEPRA manufactures the CONTRACT PRODUCTS but is not in a
position to manufacture and distribute the CONTRACT SPECIALTIES. Therefore the
PARTIES have mutually agreed to entrust the manufacture and distribution of the
CONTRACT SPECIALTIES to a third party company.

Thus the PARTIES granted to GUERBET BIOMEDICAL an exclusive, worldwide de facto
license for the manufacture and distribution of the CONTRACT SPECIALTIES, based
on a draft "manufacturing and sale licensing contract."

         4.2. It is expressly agreed by the PARTIES that the application of
articles 5 and 6 below relative to the direct or indirect use of the CONTRACT
PRODUCTS and SPECIALTIES by BIOSEPRA shall be strictly subject to the signature
by AP-HP, BIOSEPRA, and GUERBET BIOMEDICAL of a memorandum of understanding
terminating the de facto license mentioned in the preceding paragraph.

                             ARTICLE 5: RIGHT OF USE

The PARTIES agree that BIOSEPRA shall have

         - the rights associated with the CONTRACT PATENTS for the exclusive use
of the CONTRACT PRODUCTS AND SPECIALTIES,

         - for the entire world and for a period of 10 years starting from the
date the rights become effective, in accordance with article 4.2 above,
renewable with the express agreement of the parties to this contract.

         - and for a use within the SCOPE OF THE CONTRACT.

                              ARTICLE 6: LICENSES

         6.1. BIOSEPRA may grant licenses not only to COMPANIES IN THE BIOSEPRA
GROUP but also to independent third parties, provided that in each case BIOSEPRA
obtains the prior written consent of AP-HP as to the licensee and the terms of
the licensing contract.

In this respect, AP-HP must inform BIOSEPRA of its acceptance or rejection of
the licensee as well as the terms of the license according to the following
schedule:

                                                                               5
<PAGE>

         - if the license is granted to a COMPANY IN THE BIOSEPRA GROUP, AP-HP
shall have a period of 21 days to respond;

         - if the license is granted to a company other than a COMPANY IN THE
BIOSEPRA GROUP, AP-HP shall have a period of 45 days to respond.

In both cases, the period granted to AP-HP to respond shall start as of receipt
by AP-HP of the registered letter with acknowledgement of receipt sent by
BIOSEPRA notifying AP-HP of the licensing contract and the identity of the
proposed licensee.

If AP-HP rejects the proposed licensee or the term of the licensing contract,
its rejections must be well-founded and based on objective and valid reasons;
AP-HP may not wrongfully reject a licensee without a valid reason.

If AP-HP does not respond within the periods mentioned above, it shall be deemed
to have given its approval three business days after receipt of a final
notification sent by BIOSEPRA by registered letter with acknowledgement of
receipt, if no response is provided to said notification.

         6.2. BIOSEPRA and AP-HP shall decide on any modifications in the terms
of the licenses granted under the same terms expressed in item 6.1 above.

         6.3. BIOSEPRA shall provide AP-HP with a copy of each licensing
contract entered into or renewed within a period of two months following
signature of same by the parties.

         6.4. The licensing contracts shall in all cases contain clauses
according to which:

         - ASSISTANCE PUBLIQUE and BIOSEPRA may, jointly or separately, verify
the accounting books kept by the licensee as regards the use of the rights
granted to the licensee.

         - The licensee shall be bound by the confidentiality obligations as
well as by the obligations to use appropriate methods and achieve appropriate
results, and specifically as regards these last two items, by the obligations of
BIOSEPRA in application of item 1 of article 7 of this contract.

         - The licensee shall be required to notify BIOSEPRA of any improvements
developed relating to the CONTRACT PATENTS, which improvements shall
automatically benefit the licensee and BIOSEPRA.

         - In the event that any of the CONTRACT PATENTS are declared invalid by
final legal decision, the licensee may not claim any compensation,
reimbursement, or reduction of sums owed at the time the final legal decision
declaring the patent invalid is handed down.

         - The licensee shall notify BIOSEPRA annually of all information and
documents necessary for accurate knowledge of the number of sales made, any lump
sum payments made, and the sales figures.

                                                                               6
<PAGE>

                                 ARTICLE 7: USE

         7.1. BIOSEPRA agrees to directly or indirectly use the rights granted
to it under the terms of this contract and to take all necessary steps for the
most advantageous use of the CONTRACT SPECIALTIES in all countries where
CONTRACT PATENTS exists, specifically by means of active business development
and effective advertising.

BIOSEPRA agrees not to manufacture and/or distribute products that are likely to
compete with the CONTRACT PRODUCTS and/or SPECIALTIES, for the entire duration
stipulated in artitle 13 of this contract.

BIOSEPRA agrees to do its best to fill all orders as promptly as possible.

         7.2. BIOSEPRA directly or indirectly uses the rights granted to it
under its sole liability, and may not implead AP-HP in the case of litigation.

BIOSEPRA shall perform or cause to be performed by a third party of its choice,
at its own expenses or at the expense of the third party selected, all legal
registrations and other actions required in the context of the use of the
CONTRACT PRODUCTS and SPECIALTIES, specifically the registrations required by
various national and supranational patent offices, as well as any actions
required by the relevant national or supranational agencies in order to obtain
any necessary marketing authorizations.

         7.3. BIOSEPRA agrees that the CONTRACT PRODUCTS shall be manufactured
in France, without prejudice to the possibility of manufacturing same in other
countries of its choice as well.

BIOSEPRA agrees to take all necessary steps, personally or through its
licensees, so that the CONTRACT SPECIALTIES are distributed in France in
sufficient quantity to satisfy national demand, under competitive pricing
conditions.

Nonperformance of this obligation shall result in withdrawal of the exclusive
nature of the right of use granted to BIOSEPRA under the terms of this contract,
without prejudice to the possible application of the provisions of article 15
below.

                                                                               7
<PAGE>

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

                          ARTICLE 8: FINANCIAL CLAUSES

         8.1. Use Royalties

                  (a) Royalties on the sale of CONTRACT PRODUCTS made by
BIOSEPRA to independent third parties:

It is hereby agreed that royalty payments to AP-HP correspond to:

         - [**] of SALES EXCLUDING TAXES realized on sales made in 1994,- [**]
of SALES EXCLUDING TAXES realized on sales made in 1995,-[**] of SALES EXCLUDING
TAXES realized on sales made in 1996,- [**] of SALES EXCLUDING TAXES realized on
sales made in 1997 and in subsequent years;

                  (b) Royalties on the amounts paid to BIOSEPRA by the
manufacturer/distributor holding the license mentioned in article 4 of this
contract:

It is hereby agreed that AP-HP and BIOSEPRA shall each receive 50% of the
royalties received from the manufacturer/distributor.

                  (c) Royalties on the sums paid to BIOSEPRA by independent
third parties who receive a license from BIOSEPRA for the manufacture, sale,
and/or distribution of the CONTRACT PRODUCTS OR SPECIALTIES:

BIOSEPRA shall pay AP-P one half of the royalties and sums of any nature
received from the licensee.

                  (d) Royalties due for the sale and/or distribution to
independent third parties of CONTRACT PRODUCTS and/or CONTRACT SPECIALTIES by
COMPANIES IN THE BIOSEPRA GROUP:

* CONTRACT PRODUCTS: subject to the provisions of item a) above concerning the
sale by BIOSEPRA of CONTRACT PRODUCTS to independent third parties, it is hereby
agreed that AP-HP will be paid a royalty of [**] of the cumulative non-group
SALES EXCLUDING TAXES realized by the COMPANIES IN THE BIOSEPRA GROUP on the
sale and/or distribution of CONTRACT PRODUCTS to independent third parties.

* CONTRACT SPECIALTIES: it is hereby agreed that AP-HP will be paid a royalty of
[**] of the cumulative non-group SALES EXCLUDING TAXES realized by the COMPANIES
IN THE BIOSEPRA GROUP on the sale and/or distribution of CONTRACT SPECIALTIES to
independent third parties.

         8.2. Lump Sum Payments
Any lump sum payments received by BIOSEPRA and the COMPANIES IN THE BIOSEPRA
GROUP in the context of the performance of this contract shall be shared in
equal parts by

                                                                               8
<PAGE>

BIOSEPRA and AP-HP, with the exception of payments specifically earmarked for
the research, development, and promotion of the CONTRACT PRODUCTS and
SPECIALTIES such as those earmarked for obtaining marketing authorizations.

                       ARTICLE 9: ACCOUNTING AND PAYMENTS

         9.1. BIOSEPRA shall keep special accounting books containing all of the
information required for an accurate evaluation of the business transactions
performed and the sales realized by BIOSEPRA and its licensees, whether said
licensees are COMPANIES IN THE BIOSEPRA GROUP or independent third parties.

These special accounting books shall include a detailed journal of the sales of
CONTRACT PRODUCTS and CONTRACT SPECIALTIES, supported by the required and
generally used documentation. The books shall also record all lump sum payments
(import duties, guarantee payments, research and development amortization
expenses, etc.) received and/or paid by BIOSEPRA and the licensees, COMPANIES IN
THE BIOSEPRA GROUP, or independent third parties, for the assignment of any or
all of the rights of use granted to BIOSEPRA under the terms of this contract.

         9.2. These special accounting books as well as the general accounting
and analytical accounting items relating thereto shall at all times be available
to AP-HP or a representative of same, until the one year after the expiration
date of this contract. These special accounting books shall be closed on 31
December of each year.

         9.3. The sums due to AP-HP shall be paid by BIOSEPRA within ninety (90)
days of the closing of the accounts, by bank check make out to Monsieur le
Tresorier-payeur General de ASSISTANCE PUBLIQUE - HOPITAUX DE PARIS.

Failure to pay said sums within the period stipulated shall result in the
application of a penalty of 1% of the total amount of sums owed per month of
delay, at the discretion of AP-HP.

Sums owed to ASSISTANCE PUBLIQUE are understood to be excluding taxes, and
specifically excluding VAT.

                 ARTICLE 10: OBLIGATION TO PROVIDE INFORMATION

         10.1. BIOSEPRA shall include with each payment to AP-HP the
documentation required for an accurate evaluation of the sales made and the
sales figures realized.

         10.2. This documentation must include the information required to
verify the amount of the sums owed to AP-HP; in this respect, the documentation
shall include:

         - the number of sales and the sales figures realized by BIOSEPRA on the
sale and/or distribution by BIOSEPRA of the CONTRACT PRODUCTS and/or
SPECIALTIES;

                                                                               9
<PAGE>

         - the royalties received by BIOSEPRA from licensees, whether they are
COMPANIES IN THE BIOSEPRA GROUP or independent third parties, with an indication
of the royalty rate and base applicable for each of the licenses in question;

         - the number of sales and the sales figures realized by licensees,
COMPANIES IN THE BIOSEPRA GROUP, or independent third parties on the sale and/or
distribution by same of the CONTRACT PRODUCTS and/or SPECIALTIES;

         - any lump sum payments, (import duties, guarantee payments, research
and development amortization expenses, etc.) received and/or paid by BIOSEPRA
and the licensees, COMPANIES IN THE BIOSEPRA GROUP, or independent third
parties, for the assignment of any or all of the rights granted to BIOSEPRA
under the terms of this contract.

         10.3. BIOSEPRA agrees to comply with and respond promptly to any
request for additional information made by AP-HP.

                             ARTICLE 11: INVALIDITY

         11.1. AP-HP and BIOSEPRA agree not to contest the validity of the
CONTRACT PATENTS.

         11.2. If one of the CONTRACT PATENTS is declared invalid by final legal
decision in a given country or territory, and if said declaration of invalidity
results in the appearance of new competition on the market in question, AP-HP
and BIOSEPRA may meet to reexamine the conditions of commercial use of the
CONTRACT PRODUCTS and/or SPECIALTIES by BIOSEPRA and/or the licensees.

AP-HP and BIOSEPRA would meet in the same manner to examine the possible effects
of the new market situation on the joint ownership principles decided on in this
contract, and to make any necessary changes thereto.

                            ARTICLE 12: INFRINGEMENT

         12.1. The PARTIES agree to inform one another promptly if they learn of
any case of infringement by a third party of the rights conferred by the
CONTRACT PATENTS.

The PARTIES will work together to define the best strategy in this case.

         12.2. If legal action becomes necessary, it will be initiated either by
both PARTIES, jointly or by mutual representation, or by one of the PARTIES
alone. The costs associated with such action would be shared equally by the
PARTIES, or paid only by the PARTY acting alone. The same would apply for any
order to pay compensatory damages handed down against the defendant by the
court, which indemnification would be shared equally by the PARTIES or
attributed only to the PARTY who brought the action.

         12.3. Because BIOSEPRA holds the exclusive right of use associated with
the CONTRACT PATENTS, in accordance with the terms of articles 4, 5, and 6 of
this contract, BIOSEPRA shall be liable for any action for infringement brought
against it by a third party

                                                                              10
<PAGE>

within the SCOPE OF THE CONTRACT. If such action is brought, AP-HP shall provide
its assistance to BIOSEPRA.

         12.4. The PARTIES agree to provide one another with all documents,
authorizations, and signatures that they may need for performing any of the
aforementioned actions.

                              ARTICLE 13: DURATION

This contract takes effect retroactively as of 29 May 1991.

Subject to the provisions of article 15 below, this contract shall run for the
entire duration of the CONTRACT PATENTS or as long as the CONTRACT PRODUCTS
and/or SPECIALTIES are being marketed and sold.

        ARTICLE 14: TRANSFER OF OWNERSHIP / RELINQUISHMENT OR OWNERSHIP

         14.1. Each PARTY may at any time sell its share of the CONTRACT PATENTS
to a third party with the consent of the other PARTY, which latter also has a
right of first refusal for a period of three months starting from notification
of the plan to sell by the selling PARTY.

If the right of first refusal is exercised, but AP-HP and BIOSEPRA cannot agree
on a selling price, the PARTIES shall, by mutual agreement, choose an expert
registered on the list of experts with the Appeals Court, who will propose a
price. If the PARTIES cannot agree on the choice of an expert, an expert will be
appointed by the President of the District Court of Paris at the request of
either PARTY.

If there is still a disagreement as to the selling price, the price will be set
by the District Court of Paris; if the other joint owner does not accept the
price set, or does not present to the selling joint owner a third party
purchaser who accepts said price, the selling joint owner may sell its share to
a third party under financial conditions that may not be less than those set by
the Court.

The new joint owner who purchases the share of ownership of the selling PARTY
shall be required to comply with all of the conditions of this joint ownership
contract.

         14.2. If for any reason one of the PARTIES to this contract decides to
relinquish its share of joint ownership of any or all of the CONTRACT PATENTS,
it must inform the other PARTY within a reasonable period; said other PARTY will
automatically become full owner of the share of ownership for the patents in
question, without compensation or indemnity.

         14.3. The joint owner that is selling or relinquishing its share of
joint ownership shall be released from all obligations with respect to the other
joint owner, once the sale or relinquishment is recorded on the national and
supranational patent registers.

                                                                              11
<PAGE>

                            ARTICLE 15: TERMINATION

         15.1. This contract shall be automatically terminated in the case of
the court-ordered liquidation of BIOSEPRA ordered by the Commercial Court in
application of the law of 25 January 1985, as well as in the case of cessation
of business, dissolution, or voluntary liquidation of BIOSEPRA.

This contract shall not terminate in the case of a transfer of BIOSEPRA's
business activities to another company planning to continue BIOSEPRA's business
activities, subject to the agreement of AP-HP as to the identity of the
transferee. The company taking over the rights of BIOSEPRA shall be required to
assume all of the rights and obligations of BIOSEPRA under the terms of this
contract.

         15.2. This contract shall be terminated automatically by one of the
PARTIES in the case of nonperformance by the other PARTY of one or more of its
obligations under the terms of this contract.

This termination will not become effective until three months after receipt by
the defaulting PARTY of a registered letter with acknowledgement of receipt from
the PARTY making the claim, stating the reasons for the claim, unless during
this period, the defaulting PARTY performs its obligations or provides proof of
circumstances beyond its control preventing performance thereof.

The exercise of this termination option does not release the defaulting party
from its obligation to perform the obligations contracted until the effective
date of the termination, without prejudice to payment of compensation for losses
incurred by the complaining PARTY due to the early termination of the contract.

Starting as of the effective date of the termination, the joint ownership by the
PARTIES and specifically the ability of the PARTIES to use or grant licenses
shall be governed by the legal system imposed by article L.613-29 of the
Intellectual Property Code.

                           ARTICLE 16: NOTIFICATIONS

All letters, communications, or notifications whatsoever sent in application of
this contract or regarding same, must, under penalty of inadmissibility and
without prejudice to compliance with the conditions of legal, usual, or
conventional form agreed on by the PARTIES, be sent to the following people:

FOR AP-HP:
Madame la Delegue a la Recherche Clinique,
Or: Madame la Chargee de la Mission de la Valorisation Industrielle
Direction de la Politique Medicale
AP-HP, 3, avenue Victoria
751000 PARIS RP

                                                                              12
<PAGE>

FOR BIOSEPRA:
Madame le Directeur General
BIOSEPRA S.A.  35, avenue Jean-Jaures
92395 VILLENEUVE LA GARENNE

                ARTICLE 17: CONTRACT LAW - DISPUTES - LITIGATION

         17.1. This contract is subject to French law both as regards the
formation and the interpretation and performance thereof.

This contract constitutes the entire agreement between the PARTIES and replaces
and renders void all written or verbal commitments made prior to the signature
of this contract by the PARTIES.

Any modification of or addition to the content of this contract must be drawn up
as a rider between the PARTIES in due form.

         17.2. The PARTIES will make every effort to reach an amicable
resolution of any disputes arising from the interpretation or performance of the
clauses of this contract.

In the event of persistent disagreement, the Courts and Tribunals of Paris shall
have jurisdiction.

Drawn up in Paris,
on 5 January 1998
In four originals.

For BIOSEPRA                                    For L'ASSISTANCE PUBLIQUE
                                                HOPITAUX DE PARIS

[signature]

J.M. Vogel                                      Dominique Laurent
Chief Executive Officer                         Director of Medical Policy

[signature]

T. Bourdy                                       [signature]
Executive Director

Approved by the Financial Controller
For AP-HP 29 Dec [year illegible]
[signature]
Mr. Potier de Courcy

                                                                              13
<PAGE>

--------------------------------------------------------------------------------
             RIDER TO THE JOINT OWNERSHIP CONTRACT OF 5 JANUARY 1998
--------------------------------------------------------------------------------

BETWEEN

L'Assistance Publique-Hopitaux de Paris, Public Institution with headquarters at
3 Avenue Victoria 75004 Paris, RP, represented for the purposes of this rider,
by delegation of its Executive Director, by Dominique Laurent, Director of
Medical Policy, hereinafter referred to as "AP-HP."

AND

Biosepra S.A., Corporation with headquarters at 48 Avenue des Genottes 95800
Cergy-Saint-Christophe, represented for the purposes of this document by its
Executive Director, Therese Bourdy, hereinafter referred to as "BIOSEPRA."

AND

Biosphere Medical S.A., Corporation with headquarters in the Industrial Zone of
Louvres, voie 2, 95380 Louvres, represented for the purposes of this document by
its Executive Director, Marie-Paule Leroy-Landercy, hereinafter referred to as
"BIOSPHERE."

PREAMIBLE

Article 1 of the joint ownership contract signed on 5 January 1998 between AP-HP
and BIOSEPRA defined the principles of joint ownership of the patents covered in
the contract, as well as the rights and obligations of each of the parties, in
the context of the commercial use of these patents.

BIOSEPRA decided to transfer its share of ownership to BIOSPHERE. In accordance
with article 14-1 of the agreement of January 1999:

         - BIOSEPRA informed AP-HP on 22 January 1999 of this decision to
transfer.

         - AP-HP was given a period of three months to exercise its right of
first refusal

         - AP-HP informed BIOSEPRA on 1 April 1999 that it waived its right of
first refusal for Biosepra's share of ownership and agrees to the transfer to
BIOSPHERE.

         - Biosepra's share of ownership was transferred to BIOSPHERE on 13
April 1999 by means of a notarized document (appendix 1).

Copy certified true to the original.
10 February 2000
[signature]
Therese Bourdy, Executive Director

                                                                              14
<PAGE>

IT WAS PREVIOUSLY STATED AS FOLLOWS:

Article 1
In the text of the aforementioned agreement, the name BIOSEPRA will be replaced
by the name BIOSPHERE in the body of the contract.

Article 2
BIOSPHERE agrees to undertake all of the conditions of the joint ownership
contract.

Article 3
BIOSPHERE agrees to pay all sums owed to AP-HP on sales made since 1 January
1999.

Article 5 [sic]
This rider is drawn up in 4 copies, each considered an original, one for each of
the parties and one to be recorded with the INPI.

Drawn up in [blank] on 6 December 1999
(four copies)

<TABLE>

<S>                                   <C>                    <C>
L'Assistance Publique-                Biosepra S.A.          Biosphere Medical S.A.
Hopitaux de Paris,
Executive Director                    Executive Director     Executive Director
And by delegation
Director of Medical Policy
[signature]                           [signature]            [signature]
Dominique Laurent                     Therese Bourdy         Marie-Paule Leroy Landercy

</TABLE>

Approval of the Financial Controller
[signature]
Francois Potier De Courcy
12 November 1999

                                                                              15

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