STOCK OPTION AGREEMENT

            AGREEMENT, dated as of February 3, 1998, by and between BioCoral,
Inc., a Delaware corporation with its principal place of business at 3, villa de
l'Industrie, Saint-Ouen, FRANCE (the "Company") and Jean Darondel, with his
office c/o the Company (the "Optionee").

                                   WITNESSETH:

            WHEREAS, on February 3, 1998, the Board of Directors of the Company
resolved to grant an option (the "Option") to the Optionee for the purchase of
up to 200,000 shares of the Company's common stock, par value $.001 per share
(the "Common Stock") at a strike price of $3.25 (US) per share on the terms and
conditions hereinafter set forth.

            NOW, THEREFORE, in consideration of the mutual covenants contained
herein, the parties hereto agree as follows:

      1. Grant of Option. Subject to all the terms and conditions hereof, the
Company hereby grants to Optionee the right to purchase all or any part of an
aggregate of 200,000 shares of Common Stock of the Company (the "Option Shares")
at an exercise price of $3.25 per share, on the terms and conditions set forth
in this Agreement.

      2. Exercisability of Option. The Option Shares subject to the Option shall
become purchasable beginning at any time and from time to time beginning on the
date hereof and for a period of 60 months thereafter, and after the expiration
date (the "Expiration Date"), this option and all rights hereunder shall expire
and any Option Shares not purchased on or before the Expiration Date may not
thereafter be purchased hereunder. In the event Optionee fails to exercise the
option on or prior to the Expiration date, then the Option as to all Option
Shares not exercised shall expire and Optionee shall have no rights with respect
to such remainder of the Option or the Option Shares.

      3. Consideration for Grant of Option. The consideration for grant of the
Option is $10, the receipt of which is hereby acknowledged.

<PAGE>

      4. Method of Exercise of Option; Payment of Option Purchase Price. This
Option shall be exercisable at any time and from time to time, prior to the
Expiration Date, by written notice (the "Notice") to the Company at its office,
presently located at 3, villa de l'Industrie, 93400 Saint-Ouen, FRANCE. The
Notice shall state the Optionee's election to exercise this Option and the
number of Option Shares in respect of which it is being exercised, and shall be
accompanied by a check in the amount of the Exercise Price. Upon payment of the
full purchase price of the Option Shares by Optionee, the Company shall deliver
a certificate or certificates representing those shares. A certificate or
certificates for the shares as to which this Option shall have been so exercised
shall be registered in the name of the Optionee and shall be delivered to
Optionee at the address of Optionee specified in the Notice or at such other
address as Optionee shall set forth in its Notice.

      5. Non-Assignability of Option. This Option may be exercised only by the
Optionee and shall not be sold, transferred, assigned, pledged, hypothecated or
otherwise disposed of in any way (whether by operation of law or otherwise)
without the Company's prior written consent except that Optionee may, solely in
connection with a transfer of all or substantially all of his assets to an
entity or entities controlled by Optionee ("Affiliate"), sell, transfer or
assign all its interest in this Agreement to such Affiliate but only after
giving the Company at least thirty days notice in writing of the proposed sale,
transfer or assignment. Any buyer, transferee, or assignee of this Option shall
be bound by and subject to each and every provision of this Agreement and shall
not sell, transfer, assign, pledge, hypothecate or otherwise dispose of the
Option in any way (whether by operation of law or otherwise).

      6. Adjustments to Preserve Option Benefits.

            If the outstanding shares of the Company's Common Stock are
exchanged for a different number or kind of shares or securities of the Company
through stock splits, reverse stock splits, stock dividends, recapitalization or
other changes in the stock of the Company, an appropriate

<PAGE>

and proportionate adjustment shall be made in the number and kind of shares
issued upon any subsequent exercise of this Option without any change in the
aggregate purchase price to be paid for such shares. For any and all such
purposes, but only for such purposes, Optionee shall be considered to be a
shareholder of record of the Company as of the date of this Option Agreement.
Nothing in this Agreement shall preclude the Corporation from issuing additional
shares of Common Stock to any third party.

      7. Limitation of Optionee's Rights. Except as otherwise provided in
Section 6 above, Optionee shall not have any of the rights or privileges of a
shareholder of the Company in respect of any Option Shares issuable upon
exercise of this Option unless and until those shares have been paid for in full
and upon such payment in full Optionee shall be deemed to be the record holder.

      8. Purchase for Investment. The Optionee represents and agrees that if the
Optionee exercises this Option in whole or in part then those Option Shares so
acquired will be acquired for the purpose of investment and not with a view to
their resale or distribution and upon each exercise of this Option, the Optionee
will furnish to the Company a written statement to that effect, satisfactory in
form and substance to the Company and its counsel. Optionee understands and
acknowledges that the shares to be acquired pursuant to this Option will be
"restricted securities" as such term is defined under the Securities Act of
1933, as amended (the "Act") and accordingly will bear a legend indicating such
restrictions.

      9. Representations and Warranties of Optionee. As a condition to receipt
of the Option and for other good and valuable consideration, receipt of which is
hereby acknowledge, the Optionee represents and warrants to the Company as
follows:

            (i) Optionee acknowledges that the Company is a development stage
company with no significant operating history and that there are significant
risks associated with the Company's business. Accordingly, the value of the
Option and the Option Shares will be based upon

<PAGE>

the Company's development of its business which is subject to significant risks;
and

            (ii) Optionee understands that the Option and the Option Shares
(issuable upon exercise of the Option) are being offered and sold under an
exemption from registration provided by Section 4 of the Act and the regulations
promulgated thereunder, as well as applicable State law exemptions, and warrants
and represents that the Option and the Option Shares are being or will be (in
the case of the Option Shares) acquired by the undersigned solely for the
undersigned's own account, for investment purposes only, and are not being
purchased with the intent or view to resell the Option or the Option Shares or
for the resale, distribution, subdivision or fractionalization thereof.
Consequently, the undersigned must bear the economic risk of the investment for
an indefinite period of time because the Option and the Option Shares cannot be
resold or otherwise transferred unless subsequently registered under the act and
qualified under applicable State law or an opinion of qualified counsel that
indicates an exemption from registration and/or qualification is available.

      10. Notices. Any notice to be given under the terms of this Option shall
be in writing and addressed to the Company at the Company's then-present address
or to Optionee at the address provided herein, or at such other address as
either party may hereafter designate in writing to the other. Any notice or
other communication given hereunder shall have been deemed duly given when
enclosed in a properly sealed envelope addressed as aforesaid, registered or
certified and deposited postage prepaid in a post office or branch post office
or, in person, when so delivered, or by Federal Express or similar overnight
courier providing evidence of receipt.

      11. Representations of Company. The Company represents: (I) the execution,
delivery and performance of this Agreement has been duly authorized by the Board
of Directors of the Company; (ii) the consummation of the transactions
contemplated by this Agreement will not violate any provision of the Company's
Certificate of Incorporation or Bylaws; and (iii) no consent of any

<PAGE>

third party including, without limitation, federal or state regulatory agencies
is required for execution and performance of this Agreement by the Company.

      12. Governing Law. This Agreement shall be deemed to be made under and
shall be construed in accordance with the laws of the State of Delaware and
applicable Federal law without regard to conflict of law principles.

      13. Successors and Assigns. This Agreement shall be binding upon and inure
to the benefit of the parties hereto and their legal successors and permitted
assigns.

      14. Entire Understanding; Masculine / Feminine. This Agreement constitutes
the entire understanding of the parties and shall not be amended except by
written agreement between the parties. As used herein, the masculine form shall
include the feminine and vice-versa as the context shall require.

            IN WITNESS WHEREOF, the parties hereto have executed this Agreement
as of the day and year first above written.

                                        BIOCORAL, INC.


                                        By: s/ Nasser Nassiri
                                            --------------------------
                                            Nasser Nassiri, Chairman

s/ Jean Darondel
------------------------------
                                        Jean Darondel, Optionee

<PAGE>

                             STOCK OPTION AGREEMENT

            AGREEMENT, dated as of November 15, 1999, by and between BioCoral,
Inc., a Delaware corporation with its principal place of business 38 rue Anatole
France, Levallois-Perret Cedex, FRANCE (the "Company") and Jean Darondel, with
his office c/o the Company (the "Optionee").

                                   WITNESSETH:

            WHEREAS, effective as of November 15, 1999, the Board of Directors
of the Company resolved to grant an option (the "Option") to the Optionee for
the purchase of up to 100,000 shares of the Company's common stock, par value
$.001 per share (the "Common Stock") at a strike price of $0.20 (US) per share
on the terms and conditions hereinafter set forth.

            NOW, THEREFORE, in consideration of the mutual covenants contained
herein, the parties hereto agree as follows:

      1. Grant of Option. Subject to all the terms and conditions hereof, the
Company hereby grants to Optionee the right to purchase all or any part of an
aggregate of 100,000 shares of Common Stock of the Company (the "Option Shares")
at an exercise price of $0.20 per share, on the terms and conditions set forth
in this Agreement.

      2. Exercisability of Option. The Option Shares subject to the Option shall
become purchasable beginning at any time and from time to time beginning on the
date hereof and for a period of 60 months thereafter, and after the expiration
date (the "Expiration Date"), this option and all rights hereunder shall expire
and any Option Shares not purchased on or before the Expiration Date may not
thereafter be purchased hereunder. In the event Optionee fails to exercise the
option on or prior to the Expiration Date, then the Option as to all Option
Shares not exercised shall expire and Optionee shall have no rights with respect
to such remainder of the Option or the Option Shares.

      3. Consideration for Grant of Option. The consideration for grant of the
Option is $10,

<PAGE>

the receipt of which is hereby acknowledged.

      4. Method of Exercise of Option; Payment of Option Purchase Price. This
Option shall be exercisable at any time and from time to time, prior to the
Expiration Date, by written notice (the "Notice") to the Company at its office,
presently located at 38 rue Anatole France, Levallois-Perret Cedex, FRANCE. The
Notice shall state the Optionee's election to exercise this Option and the
number of Option Shares in respect of which it is being exercised, and shall be
accompanied by a check in the amount of the Exercise Price. Upon payment of the
full purchase price of the Option Shares by Optionee, the Company shall deliver
a certificate or certificates representing those shares. A certificate or
certificates for the shares as to which this Option shall have been so exercised
shall be registered in the name of the Optionee and shall be delivered to
Optionee at the address of Optionee specified in the Notice or at such other
address as Optionee shall set forth in its Notice.

      5. Non-Assignability of Option. This Option may be exercised only by the
Optionee and shall not be sold, transferred, assigned, pledged, hypothecated or
otherwise disposed of in any way (whether by operation of law or otherwise)
without the Company's prior written consent except that Optionee may, solely in
connection with a transfer of all or substantially all of his assets to an
entity or entities controlled by Optionee ("Affiliate"), sell, transfer or
assign all its interest in this Agreement to such Affiliate but only after
giving the Company at least thirty days notice in writing of the proposed sale,
transfer or assignment. Any buyer, transferee, or assignee of this Option shall
be bound by and subject to each and every provision of this Agreement and shall
not sell, transfer, assign, pledge, hypothecate or otherwise dispose of the
Option in any way (whether by operation of law or otherwise).

      6. Adjustments to Preserve Option Benefits.

      If the outstanding shares of the Company's Common Stock are exchanged for
a

<PAGE>

different number or kind of shares or securities of the Company through stock
splits, reverse stock splits, stock dividends, re-capitalization or other
changes in the stock of the Company, an appropriate and proportionate adjustment
shall be made in the number and kind of shares issued upon any subsequent
exercise of this Option without any change in the aggregate purchase price to be
paid for such shares. For any and all such purposes, but only for such purposes,
Optionee shall be considered to be a shareholder of record of the Company as of
the date of this Option Agreement. Nothing in this Agreement shall preclude the
Corporation from issuing additional shares of Common Stock to any third party.

      7. Limitation of Optionee's Rights. Except as otherwise provided in
Section 6 above, Optionee shall not have any of the rights or privileges of a
shareholder of the Company in respect of any Option Shares issuable upon
exercise of this Option unless and until those shares have been paid for in full
and upon such payment in full Optionee shall be deemed to be the record holder.

      8. Purchase for Investment. The Optionee represents and agrees that if the
Optionee exercises this Option in whole or in part then those Option Shares so
acquired will be acquired for the purpose of investment and not with a view to
their resale or distribution and upon each exercise of this Option, the Optionee
will furnish to the Company a written statement to that effect, satisfactory in
form and substance to the Company and its counsel. Optionee understands and
acknowledges that the shares to be acquired pursuant to this Option will be
"restricted securities" as such term is defined under the Securities Act of
1933, as amended (the "Act") and accordingly will bear a legend indicating such
restrictions.

      9. Representations and Warranties of Optionee. As a condition to receipt
of the Option and for other good and valuable consideration, receipt of which is
hereby acknowledge, the Optionee represents and warrants to the Company as
follows:

            (I) Optionee acknowledges that the Company is a development stage
company with no significant operating history and that there are significant
risks associated with the

<PAGE>

Company's business. Accordingly, the value of the Option and the Option Shares
will be based upon the Company's development of its business which is subject to
significant risks; and

            (II) Optionee understands that the Option and the Option Shares
(issuable upon exercise of the Option) are being offered and sold under an
exemption from registration provided by Section 4 of the Act and the regulations
promulgated thereunder, as well as applicable State law exemptions, and warrants
and represents that the Option and the Option Shares are being or will be (in
the case of the Option Shares) acquired by the undersigned solely for the
undersigned's own account, for investment purposes only, and are not being
purchased with the intent or view to resell the Option or the Option Shares or
for the resale, distribution, subdivision or fractionalization thereof.
Consequently, the undersigned must bear the economic risk of the investment for
an indefinite period of time because the Option and the Option Shares cannot be
resold or otherwise transferred unless subsequently registered under the act and
qualified under applicable State law or an opinion of qualified counsel that
indicates an exemption from registration and/or qualification is available.

      10. Notices. Any notice to be given under the terms of this Option shall
be in writing and addressed to the Company at the Company's then-present address
or to Optionee at the address provided herein, or at such other address as
either party may hereafter designate in writing to the other. Any notice or
other communication given hereunder shall have been deemed duly given when
enclosed in a properly sealed envelope addressed as aforesaid, registered or
certified, and deposited postage prepaid in a post office or branch post office
or, in person, when so delivered, or by Federal Express or similar overnight
courier providing evidence of receipt.

      11. Representations of Company. The Company represents: (i) the execution,
delivery and performance of this Agreement has been duly authorized by the Board
of Directors of the Company; (ii) the consummation of the transactions
contemplated by this Agreement will not violate any provision of the Company's
Certificate of Incorporation or Bylaws, and (iii) no consent of any

<PAGE>

third party including, without limitation, federal or state regulatory agencies
is required for execution and performance of this Agreement by the Company.

      12. Governing Law. This Agreement shall be deemed to be made under and
shall be construed in accordance with the laws of the State of Delaware and
applicable Federal law without regard to conflict of law principles.

      13. Successors and Assigns. This Agreement shall be binding upon and inure
to the benefit of the parties hereto and their legal successors and permitted
assigns.

      14. Entire Understanding; Masculine / Feminine. This Agreement constitutes
the entire understanding of the parties and shall not be amended except by
written agreement between the parties. As used herein, the masculine form shall
include the feminine and vice-versa, as the context shall require.

            IN WITNESS WHEREOF, the parties hereto have executed this Agreement
as of the day and year first above written.

                                        BIOCORAL, INC.

                                        By:
                                           ------------------------


                                        OPTIONEE

                                        By:
                                           ------------------------

<PAGE>

                             STOCK OPTION AGREEMENT

            AGREEMENT, dated as of November 15, 1999, by and between BioCoral,
Inc., a Delaware corporation with its principal place of business 38 rue Anatole
France, Levallois-Perret Cedex, FRANCE (the "Company") and Nasser Nassiri, with
his office c/o the Company (the "Optionee").

                                  WITNESSETH:

            WHEREAS, effective as of November 15, 1999, the Board of Directors
of the Company resolved to grant an option (the "Option") to the Optionee for
the purchase of up to 100,000 shares of the Company's common stock, par value
$.001 per share (the "Common Stock") at a strike price of $0.20 (US) per share
on the terms and conditions hereinafter set forth.

            NOW, THEREFORE, in consideration of the mutual covenants contained
herein, the parties hereto agree as follows:

      1. Grant of Option. Subject to all the terms and conditions hereof, the
Company hereby grants to Optionee the right to purchase all or any part of an
aggregate of 100,000 shares of Common Stock of the Company (the "Option Shares")
at an exercise price of $0.20 per share, on the terms and conditions set forth
in this Agreement.

      2. Exercisability of Option. The Option Shares subject to the Option shall
become purchasable beginning at any time and from time to time beginning on the
date hereof and for a period of 60 months thereafter, and after the expiration
date (the "Expiration Date"), this option and all rights hereunder shall expire
and any Option Shares not purchased on or before the Expiration Date may not
thereafter be purchased hereunder. In the event Optionee fails to exercise the
option on or prior to the Expiration Date, then the Option as to all Option
Shares not exercised shall expire and Optionee shall have no rights with respect
to such remainder of the Option or the Option Shares.

      3. Consideration for Grant of Option. The consideration for grant of the
Option is $10,

<PAGE>

the receipt of which is hereby acknowledged.

      4. Method of Exercise of Option; Payment of Option Purchase Price. This
Option shall be exercisable at any time and from time to time, prior to the
Expiration Date, by written notice (the "Notice") to the Company at its office,
presently located at 38 rue Anatole France, Lcvallois-Perrer Cedex, FRANCE. The
Notice shall state the Optionee's election to exercise this Option and the
number of Option Shares in respect of which it is being exercised, and shall be
accompanied by a check in the amount of the Exercise Price. Upon payment of the
full purchase price of the Option Shares by Optionee, the Company shall deliver
a certificate or certificates representing those shares. A certificate or
certificates for the shares as to which this Option shall have been so exercised
shall be registered in the name of the Optionee and shall be delivered to
Optionee at the address of Optionee specified in the Notice or at such other
address as Optionee shall set forth in its Notice.

      5. Non-Assignability of Option. This Option may be exercised only by the
Optionee and shall not be sold, transferred, assigned, pledged, hypothecated or
otherwise disposed of in any way (whether by operation of law or otherwise)
without the Company's prior written consent except that Optionee may, solely in
connection with a transfer of all or substantially all of his assets to an
entity or entities controlled by Optionee ("Affiliate"), sell, transfer or
assign all its interest in this Agreement to such Affiliate but only after
giving the Company at least thirty days notice in writing of the proposed sale,
transfer or assignment. Any buyer, transferee, or assignee of this Option shall
be bound by and subject to each and every provision of this Agreement and shall
not sell, transfer, assign, pledge, hypothecate or otherwise dispose of the
Option in any way (whether by operation of law or otherwise).

      6. Adjustments to Preserve Option Benefits.

            If the outstanding shares of the Company's Common Stock are
exchanged for a different number or kind of shares or securities of the Company
through stock splits, reverse stock splits, stock dividends, re-capitalization
or other changes in the stock of the Company, an appropriate

<PAGE>

and proportionate adjustment shall be made in the number and kind of shares
issued upon any subsequent exercise of this Option without any change in the
aggregate purchase price to be Paid for such shares. For any and all such
purposes, but only for such purposes, Optionee shall be considered to be a
shareholder of record of the Company as of the date of this Option Agreement.
Nothing in this Agreement shall preclude the Corporation from issuing additional
shares of Common Stock to any third party.

      7. Limitation of Optionee's Rights. Except as otherwise provided in
Section 6 above, Optionee shall not have any of the rights or privileges of a
shareholder of the Company in respect of any Option Shares issuable upon
exercise of this Option unless and until those shares have been paid for in full
and upon such payment in full Optionee shall be deemed to be the record holder.

      8. Purchase for Investment. The Optionee represents and agrees that if the
Optionee exercises this Option in whole or in part then those Option Shares so
acquired will be acquired for the purpose of investment and not with a view to
their resale or distribution and upon each exercise of this Option, the Optionee
will furnish to the Company a written statement to that effect, satisfactory in
form and substance to the Company and its counsel. Optionee understands and
acknowledges that the shares to be acquired pursuant to this Option will be
"restricted Securities" as such term is defined under the Securities Act of
1933, as amended (the "Act") and accordingly will bear a legend indicating such
restrictions.

      9. Representations and Warranties of Optionee. As a condition to receipt
of the Option and for other good and valuable consideration, receipt of which is
hereby acknowledge, the Optionee represents and warrants to the Company as
follows:

            (I) Optionee acknowledges that the Company is a development stage
company with no significant operating history and that there are significant
risks associated with the Company's business. Accordingly, the value of the
Option and the Option Shares will be based upon the Company's development of its
business which is subject to significant risks; and

<PAGE>

            (II) Optionee understands that the Option and the Option Shares
(issuable upon exercise of the Option) are being offered and sold under an
exemption from registration provided by Section 4 of the Act and the regulations
promulgated thereunder, as well as applicable State law exemptions, and warrants
and represents that the Option and the Option Shares are being or will be (in
the case of the Option Shares) acquired by the undersigned solely for the
undersigned's own account, for investment purposes only, and are not being
purchased with the intent or view to resell the Option or the Option Shares or
for the resale, distribution, subdivision or fractionalization thereof.
Consequently, the undersigned must bear the economic risk of the investment for
an indefinite period of time because the Option and the Option Shares cannot be
resold or otherwise transferred unless subsequently registered under the act and
qualified under applicable State law or an opinion of qualified counsel that
indicates an exemption from registration and/or qualification is available.

      10. Notices. Any notice to be given under the terms of this Option shall
he in writing and addressed to the Company at the Company's then-present address
or to Optionee at the address provided herein, or at such other address as
either party may hereafter designate in writing to the other. Any notice or
other communication given hereunder shall have been deemed duly given when
enclosed in a properly sealed envelope addressed as aforesaid, registered or
certified, and deposited postage prepaid in a post office or branch post office
or, in person, when so delivered, or by Federal Express or similar overnight
courier providing evidence of receipt.

      11. Representations of Company. The Company represents: (i) the execution,
delivery and performance of this Agreement has been duly authorized by the Board
of Directors of the Company; (ii) the consummation of the transactions
contemplated by this Agreement will not violate any provision of the Company's
Certificate of Incorporation or Bylaws; and (iii) no consent of any third party
including, without limitation, federal or state regulatory agencies is required
for execution and performance of this Agreement by the Company.

<PAGE>

      12. Governing Law. This Agreement shall be deemed to be made under and
shall be construed in accordance with the laws of the State of Delaware and
applicable Federal law without regard to conflict of law principles.

      13. Successors and Assigns. This Agreement shall be binding upon and inure
to the benefit of the parties hereto and their legal successors and permitted
assigns.

      14. Entire Understanding; Masculine / Feminine. This Agreement constitutes
the entire understanding of the parties and shall not be amended except by
written agreement between the parties. As used herein, the masculine form shall
include the feminine and vice-versa, as the context shall require.

            IN WITNESS WHEREOF, the parties hereto have executed this Agreement
as of the day and year first above written.

                                        BIOCORAL, INC.

                                        By:
                                           ------------------------


                                        OPTIONEE

                                        By:
                                           ------------------------

<PAGE>

                             STOCK OPTION AGREEMENT

            AGREEMENT, dated as of November 15, 1999, by and between BioCoral,
Inc., a Delaware corporation with its principal place of business 38 rue Anatole
France, Levallois-Perret Cedex, FRANCE (the "Company") and Ramin Almassi, with
his office c/o the Company (the "Optionee").

                                   WITNESSETH:

            WHEREAS, effective as of November 15, 1999, the Board of Directors
of the Company resolved to grant an option (the "Option") to the Optionee for
the purchase of up to 100,000 shares of the Company's common stock, par value
$.001 per share (the "Common Stock") at a strike price of $0.20 (US) per share
on the terms and conditions hereinafter set forth.

            NOW, THEREFORE, in consideration of the mutual covenants contained
herein, the parties hereto agree as follows:

      1. Grant of Option. Subject to all the terms and conditions hereof, the
Company hereby grants to Optionee the right to purchase all or any part of an
aggregate of 100,000 shares of Common Stock of the Company (the "Option Shares")
at an exercise price of $0.20 per share, on the terms and conditions set forth
in this Agreement.

      2. Exercisability of Option. The Option Shares subject to the Option shall
become purchasable beginning at any time and from time to time beginning on the
date hereof and for a period of 60 months thereafter, and after the expiration
date (the "Expiration Date"), this option and all rights hereunder shall expire
and any Option Shares not purchased on or before the Expiration Date may not
thereafter be purchased hereunder. In the event Optionee fails to exercise the
option on or prior to the Expiration Date, then the Option as to all Option
Shares not exercised shall expire and Optionee shall have no rights with respect
to such remainder of the Option or the Option Shares.

      3. Consideration for Grant of Option. The consideration for grant of the
Option is $10, the receipt of which is hereby acknowledged.

<PAGE>

      4. Method of Exercise of Option; Payment of Option Purchase Price. This
Option shall be exercisable at any time and from time to time, prior to the
Expiration Date, by written notice (the "Notice") to the Company at its office,
presently located at 38 rue Anatole France, Levallois-Perret Cedex, FRANCE. The
Notice shall state the Optionee's election to exercise this Option and the
number of Option Shares in respect of which it is being exercised, and shall be
accompanied by a check in the amount of the Exercise Price. Upon payment of the
full purchase price of the Option Shares by Optionee, the Company shall deliver
a certificate or certificates representing those shares. A certificate or
certificates for the shares as to which this Option shall have been so exercised
shall be registered in the name of the Optionee and shall be delivered to
Optionee at the address of Optionee specified in the Notice or at such other
address as Optionee shall set forth in its Notice.

      5. Non-Assignability of Option. This Option may be exercised only by the
Optionee and shall not be sold, transferred, assigned, pledged, hypothecated or
otherwise disposed of in any way (whether by operation of law or otherwise)
without the Company's prior written consent except that Optionee may, solely in
connection with a transfer of all or substantially all of his assets to an
entity or entities controlled by Optionee ("Affiliate"), sell, transfer or
assign all its interest in this Agreement to such Affiliate but only after
giving the Company at least thirty days notice in writing of the proposed sale,
transfer or assignment. Any buyer, transferee, or assignee of this Option shall
be bound by and subject to each and every provision of this Agreement and shall
not sell, transfer, assign, pledge, hypothecate or otherwise dispose of the
Option in any way (whether by operation of law or otherwise)

      6. Adjustments to Preserve Option Benefits.

            If the outstanding shares of the Company's Common Stock are
exchanged for a different number or kind of shares or securities of the Company
through stock splits, reverse stock splits, stock dividends, re-capitalization
or other changes in the stock of the Company, an appropriate and proportionate
adjustment shall be made in the number and kind of shares issued upon any

<PAGE>

subsequent exercise of this Option without any change in the aggregate purchase
price to be paid for such shares. For any and all such purposes, but only for
such purposes, Optionee shall be considered to be a shareholder of record of the
Company as of the date of this Option Agreement. Nothing in this Agreement shall
preclude the Corporation from issuing additional shares of Common Stock to any
third party.

      7. Limitation of Optionee's Rights. Except as otherwise provided in
Section 6 above, Optionee shall not have any of the rights or privileges of a
shareholder of the Company in respect of any Option Shares issuable upon
exercise of this Option unless and until those shares have been paid for in full
and upon such payment in full Optionee shall be deemed to be the record holder

      8. Purchase for Investment. The Optionee represents and agrees that if the
Optionee exercises this Option in whole or in part then those Option Shares so
acquired will be acquired for the purpose of investment and not with a view to
their resale or distribution and upon each exercise of this Option, the Optionee
will furnish to the Company a written statement to that effect, satisfactory in
form and substance to the Company and its counsel. Optionee understands and
acknowledges that the shares to be acquired pursuant to this Option will be
"restricted securities" as such term is defined under the Securities Act of
1933, as amended (the "Act") and accordingly will bear a legend indicating such
restrictions.

      9. Representations and Warranties of Optionee. As a condition to receipt
of the Option and for other good and valuable consideration, receipt of which is
hereby acknowledge, the Optionee represents and warrants to the Company as
follows:

            (I) Optionee acknowledges that the Company is a development stage
company with no significant operating history and that there are significant
risks associated with the Company's business. Accordingly, the value of the
Option and the Option Shares will be based upon the Company's development of its
business which is subject to significant risks; and

            (II) Optionee understands that the Option and the Option Shares

<PAGE>

(issuable upon exercise of the Option) are being offered and sold under an
exemption from registration provided by Section 4 of the Act and the regulations
promulgated thereunder, as well as applicable State law exemptions, and warrants
and represents that the Option and the Option Shares are being or will be (in
the case of the Option Shares) acquired by the undersigned solely for the
undersigned's own account, for investment purposes only, and are not being
purchased with the intent or view to resell the Option or the Option Shares or
for the resale, distribution, subdivision or fractionalization thereof.
Consequently, the undersigned must bear the economic risk of the investment for
an indefinite period of time because the Option and the Option Shares cannot be
resold or otherwise transferred unless subsequently registered under the act and
qualified under applicable State law or an opinion of qualified counsel that
indicates an exemption from registration and/or qualification is available.

      10. Notices. Any notice to be given under the terms of be in writing and
addressed to the Company at the Company's then-present address or to Optionee at
the address provided herein, or at such other address as either party may
hereafter designate in writing to the other. Any notice or other Communication
given hereunder shall have been deemed duly given then enclosed in a properly
sealed envelope addressed as aforesaid, registered or certified, and deposited
postage prepaid in a post office or branch post office or, in person, when so
delivered, or by Federal Express or similar overnight courier providing evidence
of receipt.

      11. Representations of Company. The Company represents: (i) the execution,
delivery and performance of this Agreement has been duly authorized by the Board
of Directors of the Company, (ii) the consummation of the transactions
contemplated by this Agreement will not violate any provision of the Company's
Certificate of incorporation or Bylaws, and (iii) no consent of any third party
including, without limitation, federal or state regulatory agencies is required
for execution and performance of this Agreement by the Company.

      12. Governing Law. This Agreement shall be deemed to be made under and
shall be

<PAGE>

construed in accordance with the laws of the State of Delaware and applicable
Federal law without regard to conflict of law principles.

      13. Successors and Assigns. This Agreement shall be binding upon and inure
to the benefit of the parties hereto and their legal successors and permitted
assigns.

      14. Entire Understanding; Masculine / Feminine. This Agreement constitutes
the entire understanding of the parties and shall not be amended except by
written agreement between the parties. As used herein, the masculine form shall
include the feminine and vice-versa, as the context shall require.

      IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the day and year first above written.

                                        BIOCORAL, INC.

                                        By:
                                           ------------------------


                                        OPTIONEE

                                        By:
                                           ------------------------

<PAGE>

                             STOCK OPTION AGREEMENT

            AGREEMENTS dated as of December 30, 1999, by and between BioCoral,
Inc., a Delaware corporation with its principal place of business 38 rue Anatole
France, Levallois-Perret Cedex, FRANCE (the "Company") and Yuhko Grossman, with
his office c/o the Company (the "Optionee").

                                   WITNESSETH:

            WHEREAS, effective as of December 30, 1999, the Board of Directors
of the Company resolved to grant an option (the "Option") to the Optionee for
the purchase of up to 250,000 shares of the Company's common stock, par value
$.001 per share (the "Common Stock") at a strike price of $0.08 (US) per share
on the terms and conditions hereinafter set forth.

            NOW, THEREFORE, in consideration of the mutual covenants contained
herein, the parties hereto agree as follows:

      1. Grant of Option. Subject to all the terms and conditions hereof, the
Company hereby grants to Optionee the right to purchase all or any part of an
aggregate of 250,000 shares of Common Stock of the Company (the "Option
Shares") at an exercise price of $0.08 per share, on the terms and conditions
set forth in this Agreement.

      2. Exercisability of Option. The Option Shares subject to the Option shall
become purchasable beginning at any time and from time to time beginning on the
date hereof and for a period of 60 months thereafter, and after the expiration
date (the "Expiration Date"), this option and all rights hereunder shall expire
and any Option Shares not purchased on or before the Expiration Date may not
thereafter be purchased hereunder, in the event Optionee fails to exercise the
option on or prior to the Expiration Date, then the Option as to all Option
Shares not exercised shall expire and Optionee shall have no rights with respect
to such remainder of the Option or the Option Shares.

<PAGE>

      3. Consideration for Grant of Option. The consideration for grant of the
Option is $10, the receipt of which is hereby acknowledged.

      4. Method of Exercise of Option; Payment of Option Purchase Price. This
Option shall be exercisable at any time and from time to time, prior to the
Expiration Date, by written notice (the "Notice") to the Company at its office,
presently located at 38 rue Anatole France, Levallois-Perret Cedex, FRANCE. The
Notice shall state the Optionee's election to exercise this Option and the
number of Option Shares in respect of which it is being exercised, and shall be
accompanied by a check in the amount of the Exercise Price. Upon payment of the
full purchase price of the Option Shares by Optionee, the Company shall deliver
a certificate or certificates representing those shares. A certificate or
certificates for the shares as to which this Option shall have been so exercised
shall be registered in the name of the Optionee and shall be delivered to
Optionee at the address of Optionee specified in the Notice or at such other
address as Optionee shall set forth in its Notice

      5. Non-Assignability of Option. This Option may be exercised only by the
Optionee and shall not be sold, transferred, assigned, pledged, hypothecated or
otherwise disposed of in any way (whether by operation of law or otherwise)
without the Company's prior written consent except that Optionee may, solely in
connection with a transfer of all or substantially all of his assets to an
entity or entities controlled by Optionee ("Affiliate"), sell, transfer or
assign all its interest in this Agreement to such Affiliate but only after
giving the Company at least thirty days notice in writing of the proposed sale,
transfer or assignment. Any buyer, transferee, or assignee of this Option shall
be bound by and subject to each and every provision of this Agreement and shall
not sell, transfer. assign, pledge, hypothecate or otherwise dispose of the
Option in any way (whether by operation of law or otherwise).

<PAGE>

      6. Adjustments to Preserve Option Benefits.

            If the outstanding shares of the Company's Common Stock are
exchanged for a different number or kind of shares or securities of the Company
through stock splits, reverse stock splits, stock dividends, re-capitalization
or other changes in the stock of the Company, an appropriate and proportionate
adjustment shall be made in the number and kind of shares issued upon any
subsequent exercise of this Option without any change in the aggregate purchase
price to be paid for such shares. For any and all such purposes, but only for
such purposes, Optionee shall be considered to be a shareholder of record of the
Company as of the date of this Option Agreement. Nothing in this Agreement shall
preclude the Corporation from issuing additional shares of Common Stock to any
third party.

      7. Limitation of Optionee's Rights. Except as otherwise provided in
Section 6 above, Optionee shall not have any of the rights or privileges of a
shareholder of the Company in respect of any Option Shares issuable upon
exercise of this Option unless and until those shares have been paid for in full
and upon such payment in full Optionee shall be deemed to be the record holder.

      8. Purchase for Investment. The Optionee represents and agrees that if the
Optionee exercises this Option in whole or in part then those Option Shares so
acquired will be acquired for the purpose of investment and not with a view to
their resale or distribution and upon each exercise of this Option, the Optionee
will furnish to the Company a written statement to that effect, satisfactory in
form and substance to the Company and its counsel. Optionee understands and
acknowledges that the shares to be acquired pursuant to this Option will be
"restricted securities" as such term is defined under the Securities Act of
1933, as amended (the "Act") and accordingly will bear a legend indicating such
restrictions.

      9. Representations and Warranties of Optionee. As a condition to receipt
of the Option and for other good and valuable consideration, receipt of which is
hereby acknowledge, the Optionee

<PAGE>

represents and warrants to the Company as follows:

            (I) Optionee acknowledges that the Company is a development stage
company with no significant operating history and that there are significant
risks associated with the Company's business. Accordingly, the value of the
Option and the Option Shares will be based upon the Company's development of its
business which is subject to significant risks; and

            (II) Optionee understands that the Option and the Option Shares
(issuable upon exercise of the Option) are being offered and sold under an
exemption from registration provided by Section 4 of the Act and the regulations
promulgated thereunder, as well as applicable State law exemptions, and warrants
and represents that the Option and the Option Shares are being or will be (in
the case of the Option Shares) acquired by the undersigned solely for the
undersigned's own account, for investment purposes only, and are not being
purchased with the intent or view to resell the Option or the Option Shares or
for the resale, distribution, subdivision or fractionalization thereof.
Consequently, the undersigned must bear the economic risk of the investment for
an indefinite period of time because the Option and the Option Shares cannot be
resold or otherwise transferred unless subsequently registered under the act and
qualified under applicable State law or an opinion of qualified counsel that
indicates an exemption from registration and/or qualification is available.

      10. Notices. Any notice to be given under the terms of this Option shall
be in writing and addressed to the Company at the Company's then-present address
or to Optionee at the address provided herein, or at such other address as
either party may hereafter designate in writing to the other. Any notice or
other communication given hereunder shall have been deemed duly given when
enclosed in a properly sealed envelope addressed as aforesaid, registered or
certified, and deposited postage prepaid in a post office or branch post office
or, in person, when so delivered, or by Federal Express or similar overnight
courier providing evidence of receipt.

<PAGE>

      11. Representations of Company. The Company represents: (i) the execution,
delivery and performance of this Agreement has been duly authorized by the Board
of Directors of the Company; (ii) the consummation of the transactions
contemplated by this Agreement will not violate any provision of the Company's
Certificate of Incorporation or Bylaws; and (iii) no consent of any third party
including, without limitation, federal or state regulatory agencies is required
for execution and performance of this Agreement by the Company.

      12. Governing Law. This Agreement shall be deemed to be made under and
shall be construed in accordance with the laws of the State of Delaware and
applicable Federal law without regard to conflict of law principles.

      13. Successors and Assigns. This Agreement shall be binding upon and inure
to the benefit of the parties hereto and their legal Successors and permitted
assigns.

      14. Entire Understanding; Masculine / Feminine. This Agreement constitutes
the entire understanding of the parties and shall not be amended except by
written agreement between the parties. As used herein, the masculine form shall
include the feminine and vice-versa, as the context shall require.

            IN WITNESS WHEREOF, the parties hereto have executed this Agreement
as of the day and year first above written.

                                        BIOCORAL, INC.

                                        By:
                                           ------------------------


                                        OPTIONEE

                                        By:
                                           ------------------------

<PAGE>

                             STOCK OPTION AGREEMENT

            AGREEMENT, dated as of December 30, 1999, by and between BioCoral,
Inc., a Delaware corporation with its principal place of business 38 rue Anatole
France, Levallois-Perret Cedex, FRANCE (the "Company") and Nasser Nassiri, with
his office c/o the Company (the "Optionee").

                                   WITNESSETH:

            WHEREAS, effective as of December 30, 1999, the Board of Directors
of the Company resolved to grant an option (the "Option") to the Optionee for
the purchase of up to 250,000 shares of the Company's common stock, par value
$.001 per share (the "Common Stock") at a strike price of $0.08 (US) per share
on the terms and conditions hereinafter set forth.

            NOW, THEREFORE, in consideration of the mutual covenants contained
herein, the parties hereto agree as follows:

      1. Grant of Option, Subject to all the terms and conditions hereof, the
Company hereby grants to Optionee the right to purchase all or any part of an
aggregate of 250,000 shares of Common Stock of the Company (the "Option Shares")
at an exercise price of $0.08 per share, on the terms and conditions set forth
in this Agreement.

      2. Exercisability of Option. The Option Shares subject to the Option shall
become purchasable beginning at any time and from time to time beginning on the
date hereof and for a period of 60 months thereafter, and after the expiration
date (the "Expiration Date"), this option and all rights hereunder shall expire
and any Option Shares not purchased on or before the Expiration Date may not
thereafter be purchased hereunder. In the event Optionee fails to exercise the
option on or prior to the Expiration Date, then the Option as to all Option
Shares not exercised shall expire and Optionee shall have no rights with respect
to such remainder of the Option or the Option Shares.

<PAGE>

      3. Consideration for Grant of Option. The consideration for grant of the
Option is $10, the receipt of which is hereby acknowledged.

      4. Method of Exercise of Option; Payment of Option Purchase Price. This
Option shall be exercisable at any time and from time to time, prior to the
Expiration Date, by written notice (the "Notice") to the Company at its office,
presently located at 38 rue Anatole France, Levallois-Perret Cedex, FRANCE. The
Notice shall state the Optionee's election to exercise this Option and the
number of Option Shares in respect of which it is being exercised, and shall be
accompanied by a check in the amount of the Exercise Price. Upon payment of the
full purchase price of the Option Shares by Optionee, the Company shall deliver
a certificate or certificates representing those shares. A certificate or
certificates for the shares as to which this Option shall have been so exercised
shall be registered in the name of the Optionee and shall be delivered to
Optionee at the address of Optionee specified in the Notice or at such other
address as Optionee shall set forth in its Notice.

      5. Non-Assignability of Option. This Option may be exercised only by the
Optionee and shall not be sold, transferred, assigned, pledged, hypothecated or
otherwise disposed of in any way (whether by operation of law or otherwise)
without the Company's prior written consent except that Optionee may, solely in
connection with a transfer of all or substantially all of his assets to an
entity or entities controlled by Optionee ("Affiliate"), sell, transfer or
assign all its interest in this Agreement to such Affiliate but only after
giving the Company at least thirty days notice in writing of the proposed sale,
transfer or assignment. Any buyer, transferee, or assignee of this Option shall
be bound by and subject to each and every provision of this Agreement and shall
not sell, transfer, assign, pledge, hypothecate or otherwise dispose of the
Option in any way (whether by operation of law or otherwise).

<PAGE>

      6. Adjustments to Preserve Option Benefits.

            If the outstanding shares of the Company's Common Stock are
exchanged for a different number or kind of shares or securities of the Company
through stock splits, reverse stock splits, stock dividends, re-capitalization
or other changes in the stock of the Company, an appropriate and proportionate
adjustment shall be made in the number and kind of shares issued upon any
subsequent exercise of this Option without any change in the aggregate purchase
price to be paid for such shares. For any and all such purposes, but only for
such purposes, Optionee shall be considered to be a shareholder of record of the
Company as of the date of this Option Agreement. Nothing in this Agreement shall
preclude the Corporation from issuing additional shares of Common Stock to any
third party.

      7. Limitation of Optionee's Rights. Except as otherwise provided in
Section 6 above, Optionee shall not have any of the rights or privileges of a
shareholder of the Company in respect of any Option Shares issuable upon
exercise of this Option unless and until those shares have been paid for in full
and upon such payment in full Optionee shall be deemed to be the record holder.

      8. Purchase for Investment. The Optionee represents and agrees that if the
Optionee exercises this Option in whole or in part then those Option Shares so
acquired will be acquired for the purpose of investment and not with a view to
their resale or distribution and upon each exercise of this Option, the Optionee
will furnish to the Company a written statement to that effect, satisfactory in
form and substance to the Company and its counsel. Optionee understands and
acknowledges that the shares to be acquired pursuant to this Option will be
"restricted securities' as such term is defined under the Securities Act of
1933, as amended (the "Act") and accordingly will bear a legend indicating such
restrictions.

      9. Representations and Warranties of Optionee. As a condition to receipt
of the Option and for other good and valuable consideration, receipt of which is
hereby acknowledge, the Optionee

<PAGE>

represents and warrants to the Company as follows:

            (I) Optionee acknowledges that the Company is a development stage
company with no significant operating history and that there are significant
risks associated with the Company's business. Accordingly, the value of the
Option and the Option Shares will be based upon the Company's development of its
business which is subject to significant risks; and

            (II) Optionee understands that the Option and the Option Shares
(issuable upon exercise of the Option) are being offered and sold under an
exemption from registration provided by Section 4 of the Act and the regulations
promulgated thereunder) as well as applicable State law exemptions, and warrants
and represents that the Option and the Option Shares are being or will be (in
the case of the Option Shares) acquired by the undersigned solely for the
undersigned's own account, for investment purposes only, and are not being
purchased with the intent or view to resell the Option or the Option Shares or
for the resale, distribution, subdivision or fractionalization thereof.
Consequently, the undersigned must bear the economic risk of the investment for
an indefinite period of time because the Option and the Option Shares cannot be
resold or otherwise transferred unless subsequently registered under the act and
qualified under applicable State law or an opinion of qualified counsel that
indicates an exemption from registration and/or qualification is available.

      10. Notices. Any notice to be given under the terms of this Option shall
be in writing and addressed to the Company at the Company's then-present address
or to Optionee at the address provided herein, or at such other address as
either party may hereafter designate in writing to the other. Any notice or
other communication given hereunder shall have been deemed duly given when
enclosed in a properly sealed envelope addressed as aforesaid, registered or
certified, and deposited postage prepaid in a post office or branch post office
or, in person, when so delivered, or by Federal Express or similar overnight
courier providing evidence of receipt.

<PAGE>

      11. Representations of Company. The Company represents: (i) the execution,
delivery and performance of this Agreement has been duly authorized by the Board
of Directors of the Company; (ii) the consummation of the transactions
contemplated by this Agreement will not violate any provision of the Company's
Certificate of Incorporation or Bylaws; and (iii) no consent of any third party
including, without limitation, federal or state regulatory agencies is required
for execution and performance of this Agreement by the Company.

      12. Governing Law. This Agreement shall be deemed to be made under and
shall be construed in accordance with the laws of the State of Delaware and
applicable Federal law without regard to conflict of law principles.

      13. Successors and Assigns. This Agreement shall be binding upon and inure
to the benefit of the parties hereto and their legal successors and permitted
assigns.

      14. Entire Understanding; Masculine / Feminine. This Agreement constitutes
the entire understanding of the parties and shall not be amended except by
written agreement between the parties. As used herein, the masculine form shall
include the feminine and vice-versa, as the context shall require.

            IN WITNESS WHEREOF, the parties hereto have executed this Agreement
as of the day and year first above written.

                                        BIOCORAL, INC.

                                        By:
                                           ------------------------


                                        OPTIONEE

                                        By:
                                           ------------------------