<PAGE>

Exhibit 4.1




                        GENSCI REGENERATION SCIENCES INC.

                              AMENDED AND RESTATED
                                STOCK OPTION PLAN





<PAGE>


<TABLE>
<CAPTION>

                                                  TABLE OF CONTENTS

                                                                                                               PAGE
<S>     <C>                                                                                                     <C>

ARTICLE 1 DEFINITIONS AND INTERPRETATION..........................................................................1

   1.1  Definitions...............................................................................................1
   1.2  Choice of Law.............................................................................................2
   1.3  Headings..................................................................................................2

ARTICLE 2 PURPOSE AND PARTICIPATION...............................................................................2

   2.1  Purpose...................................................................................................2
   2.2  Participation.............................................................................................2
   2.3  Notification of Award.....................................................................................3
   2.4  Copy of Plan..............................................................................................3
   2.5  Limitation................................................................................................3

ARTICLE 3 TERMS AND CONDITIONS OF OPTIONS.........................................................................3

   3.1  Board to Allot Shares.....................................................................................3
   3.2  Number of Shares..........................................................................................3
   3.3  Term of Option............................................................................................3
   3.4  Termination of Option.....................................................................................4
   3.6  Assignment of Options.....................................................................................4
   3.7  Adjustments...............................................................................................5
   3.8  Vesting...................................................................................................5

ARTICLE 4 EXERCISE OF OPTION......................................................................................5

   4.1  Exercise of Option........................................................................................5
   4.2  Issue of Share Certificates...............................................................................5
   4.3  Condition of Issue........................................................................................5

ARTICLE 5 STOCK APPRECIATION RIGHTS...............................................................................6

   5.1  Stock Appreciation Rights.................................................................................6
   5.2  Stock Appreciation Rights Tied to Options.................................................................6
   5.3  Terms of Stock Appreciation Rights........................................................................6
   5.4  Exercise of Stock Appreciation Rights.....................................................................6

ARTICLE 6ADMINISTRATION...........................................................................................6

   6.1  Administration............................................................................................6
   6.2  Interpretation............................................................................................7

ARTICLE 7 AMENDMENT AND TERMINATION...............................................................................7

   7.1  Prospective Amendment.....................................................................................7
   7.2  Retrospective Amendment...................................................................................7
   7.3  Termination...............................................................................................7
   7.4  Agreement.................................................................................................7

ARTICLE 8 APPROVALS REQUIRED FOR PLAN.............................................................................7

   8.1  Approvals Required for Plan...............................................................................7
   8.2  Substantive Amendments to Plan............................................................................8

</TABLE>


<PAGE>

                              AMENDED AND RESTATED
                                STOCK OPTION PLAN


                                    ARTICLE 1
                         DEFINITIONS AND INTERPRETATION

1.1      DEFINITIONS

As used herein, unless anything in the subject matter or context is inconsistent
therewith, the following terms shall have the meanings set forth below:

         (a)      "Administrator" means, initially, the secretary of the Company
                  and  thereafter  shall  mean  such  director  or other  senior
                  officer or  employee of the  Company as may be  designated  as
                  Administrator by the Board from time to time;

         (b)      "Award  Date"  means the date on which the  Board  grants  and
                  announces a particular Option;

         (c)      "Board" means the board of directors of the Company;

         (d)      "Director" means any individual holding the office of director
                  of the Company;

         (e)      "Company"  means  GenSci  Regeneration  Sciences  Inc.  or any
                  "affiliate" (as defined under the Company Act, R.S.B.C.  1996,
                  c. 62, as amended);

         (f)      "Employee"  means  any  individual  regularly  employed  on  a
                  full-time or part-time  basis by the Company or other  persons
                  who perform management or consulting  services for the Company
                  on an ongoing basis;

         (g)      "Exercise  Notice" means the notice respecting the exercise of
                  an Option or a stock  appreciation  right, in the form set out
                  as Schedule "B" hereto, duly executed by the Option Holder;

         (h)      "Exercise  Period"  means the period during which a particular
                  Option may be exercised  and is the period from and  including
                  the Award Date through to and including the Expiry Date;

         (i)      "Exercise  Price"  means the  price at which an Option  may be
                  exercised as determined in accordance with section 3.5;

         (j)      "Expiry Date" means the date  determined  in  accordance  with
                  section  3.3 and after  which a  particular  Option  cannot be
                  exercised;

         (k)      "Option"  means an  option to  acquire  Shares,  awarded  to a
                  Director  or  Employee  pursuant  to the  Plan,  and  for  the
                  purposes of section 3.2 of this Plan,  Option  includes  stock
                  options  granted  prior to the  adoption  of this  Plan or any
                  predecessor stock option plan;

         (l)      "Option  Certificate" means the certificate,  substantially in
                  the form set out as Schedule "A" hereto, evidencing an Option;


<PAGE>

         (m)      "Option  Holder"  means  a  Director  or  Employee  or  former
                  Director or Employee,  who holds an unexercised  and unexpired
                  Option or, where  applicable,  the Personal  Representative of
                  such person;

         (n)      "Plan"  means this GenSci  Regeneration  Sciences  Inc.  stock
                  option plan;

         (o)      "Personal Representative" means:

                        (i)         in the case of a deceased Option Holder, the
                                    executor or  administrator  of the  deceased
                                    duly   appointed   by  a  court  or   public
                                    authority having jurisdiction to do so; and

                       (ii)         in the case of an Option  Holder who for any
                                    reason  is  unable  to  manage  his  or  her
                                    affairs,  the person  entitled by law to act
                                    on behalf of such Option Holder;

         (p)      "Share"  or  "Shares"  means,  as the case may be, one or more
                  common shares without par value in the capital of the Company.

1.2      CHOICE OF LAW

The  Plan  is  established  under  and  the  provisions  of the  Plan  shall  be
interpreted and construed in accordance with the laws of the Province of British
Columbia.

1.3      HEADINGS

The  headings  used  herein are for  convenience  only and are not to affect the
interpretation of the Plan.


                                    ARTICLE 2
                            PURPOSE AND PARTICIPATION

2.1      PURPOSE

The purpose of the Plan is to provide the Company with a share-related mechanism
to attract,  retain and motivate  qualified  Directors and Employees,  to reward
such of those  Directors and Employees as may be awarded  Options under the Plan
by the  Board  from time to time for their  contributions  toward  the long term
goals of the Company and to enable and encourage such Directors and Employees to
acquire Shares as long term investments.

2.2      PARTICIPATION

The Board  shall,  from time to time,  in its sole  discretion  determine  those
Directors and Employees, if any, to whom Options are to be awarded. If the Board
elects to award an Option to a Director, the Board shall, in its sole discretion
but subject to section 3.2, determine the number of Shares to be acquired on the
exercise of such Option.  If the Board elects to award an Option to an Employee,
the number of Shares to be  acquired on the  exercise  of such  Option  shall be
determined  by the Board in its sole  discretion,  and in so doing the Board may
take into account the following criteria:


                                       2
<PAGE>

         (a)      the  annual  salary of the  Employee  as at the Award  Date in
                  relation to the total annual  salaries  payable by the Company
                  to all of its Employees as at the Award Date;

         (b)      the length of time that the Employee has been  employed by the
                  Company; and

         (c)      the quality of work performed by the Employee.

2.3      NOTIFICATION OF AWARD

Following  the  approval  by  the  Board  of  the  awarding  of an  Option,  the
Administrator  shall notify the Option  Holder in writing of the award and shall
enclose  with such  notice the  Option  Certificate  representing  the Option so
awarded.

2.4      COPY OF PLAN

Each  Option  Holder,  concurrently  with the notice of the award of the Option,
shall be provided  with a copy of the Plan. A copy of any  amendment to the Plan
shall be promptly provided by the Administrator to each Option Holder.

2.5      LIMITATION

The Plan does not give any Option  Holder that is a Director  the right to serve
or  continue  to serve as a Director  of the Company nor does it give any Option
Holder that is an Employee  the right to be or to continue to be employed by the
Company.


                                    ARTICLE 3
                         TERMS AND CONDITIONS OF OPTIONS

3.1      BOARD TO ALLOT SHARES

The Shares to be issued to Option  Holders upon the exercise of Options shall be
allotted and authorized for issuance by the Board prior to the exercise thereof.

3.2      NUMBER OF SHARES

The maximum  number of Shares  that may be issued  upon the  exercise of Options
shall not exceed  4,100,000  Shares of the  Company.  Additionally,  the Company
shall not grant  Options to any one person which will,  when  exercised,  exceed
five percent (5%) of the issued and outstanding Shares of the Company.

If any Option  expires or otherwise  terminates in accordance  with the terms of
the Plan without  having been exercised in full, the number of Shares in respect
of which Option expired or terminated  shall again be available for the purposes
of the Plan.

3.3      TERM OF OPTION

Subject to section  3.4, the Expiry Date of an Option shall be the date so fixed
by the Board at the time the  particular  Option is awarded,  provided that such
date  shall not be later  than the tenth  anniversary  of the Award Date of such
Option.


                                       3
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3.4      TERMINATION OF OPTION

An Option  Holder may exercise an Option in whole or in part at any time or from
time to time during the  Exercise  Period  provided  that,  with  respect to the
exercise  of part of an Option,  the Board may at any time and from time to time
fix a minimum or maximum  number of Shares in respect of which an Option  Holder
may exercise part of any Option held by such Option  Holder.  Any Option or part
thereof not  exercised  within the Exercise  Period shall  terminate  and become
null,  void and of no effect as of 5:00 p.m.  local time in  Vancouver,  British
Columbia,  on the Expiry Date. The Expiry Date of an Option shall be the earlier
of the date so fixed by the Board at the time the Option is awarded and the date
established, if applicable, in paragraphs (a) to (c) below:

         (a)      DEATH

                  In the event that the Option Holder should die while he or she
                  is still a  Director  (if he or she holds his or her Option as
                  Director) or Employee (if he or she holds his or her Option as
                  Employee),  the Expiry  Date shall be six (6) months  from the
                  date of death of the Option Holder; or

         (b)      CEASING TO HOLD OFFICE

                  In the event that the Option Holder holds his or her Option as
                  Director of the Company and such Option  Holder ceases to be a
                  Director  of the  Company  other than by reason of death,  the
                  Expiry Date of the Option shall be the 30th day  following the
                  date the Option  Holder ceases to be a Director of the Company
                  unless  the  Option  Holder  ceases  to be a  Director  of the
                  Company  but  continues  to be  engaged  by the  Company as an
                  Employee,   in  which  case  the  Expiry  Date  shall   remain
                  unchanged.

         (c)      CEASING TO BE EMPLOYED

                  In the event that the Option Holder holds his or her Option as
                  an Employee of the Company and such Option Holder ceases to be
                  an Employee of the Company other than by reason of death,  the
                  Expiry Date of the Option shall be the 30th day  following the
                  date the Option Holder ceases to be an Employee of the Company
                  unless  the  Option  Holder  ceases to be an  Employee  of the
                  Company as a result of termination for cause in which case the
                  Expiry Date shall be the date the Option  Holder  ceases to be
                  an Employee of the Company.

3.5      EXERCISE PRICE

The Exercise Price shall be that price per share,  as determined by the Board in
its sole  discretion  and  announced  as of the Award  Date,  at which an Option
Holder may  purchase a Share upon the  exercise  of an Option,  and shall not be
less  than the  closing  price of the  Company's  Shares  on The  Toronto  Stock
Exchange  (or,  if the Shares are no longer  listed for  trading on The  Toronto
Stock Exchange, then such other exchange or quotation system on which the Shares
are listed or quoted for trading) on the day preceding the Award Date.

3.6      ASSIGNMENT OF OPTIONS

Options may not be assigned or transferred,  provided  however that the Personal
Representative  of an Option Holder may, to the extent permitted by section 4.1,
exercise the Option within the Exercise Period.


                                       4
<PAGE>

3.7      ADJUSTMENTS

If prior to the  complete  exercise  of any Option the Shares are  consolidated,
subdivided,  converted,  exchanged or reclassified or in any way substituted for
(collectively  the  "Event"),  an  Option,  to the  extent  that it has not been
exercised,  shall be adjusted by the Board in accordance  with such Event in the
manner the Board deems  appropriate.  No fractional  Shares shall be issued upon
the  exercise of the Options and  accordingly,  if as a result of the Event,  an
Option Holder would become  entitled to a fractional  share,  such Option Holder
shall have the right to purchase only the next lowest whole number of shares and
no  payment or other  adjustment  will be made with  respect  to the  fractional
interest so disregarded.  Additionally, no lots of Shares in an amount less than
500 Shares shall be issued upon the exercise of the Option unless such amount of
Shares represents the balance left to be exercised under the Option.

3.8      VESTING

The Board may, in its sole  discretion  at the time the Option is  granted,  but
will not be required to, impose conditions  relating to the vesting of the right
to  exercise  an Option  granted to any Option  Holder.  The Option  Certificate
representing any such Option will disclose any vesting conditions.


                                    ARTICLE 4
                               EXERCISE OF OPTION

4.1      EXERCISE OF OPTION

An  Option  may  be  exercised  only  by  the  Option  Holder  or  the  Personal
Representative   of  any  Option  Holder.  An  Option  Holder  or  the  Personal
Representative  of any Option  Holder may exercise an Option in whole or in part
at any time or from  time to time  during  the  Exercise  Period up to 5:00 p.m.
local  time in  Vancouver,  British  Columbia  (or  such  other  place as may be
designated by the Board) on the Expiry Date by  delivering to the  Administrator
an Exercise Notice,  the applicable Option Certificate and a certified cheque or
bank draft payable to the Company in an amount equal to the  aggregate  Exercise
Price of the Shares to be purchased pursuant to the exercise of the Option.

4.2      ISSUE OF SHARE CERTIFICATES

As soon as  practicable  following  the  receipt  of the  Exercise  Notice,  the
Administrator shall cause to be delivered to the Option Holder a certificate for
the Shares so  purchased.  If the number of Shares so purchased is less than the
number  of  Shares   subject  to  the  Option   Certificate   surrendered,   the
Administrator  shall  forward a new  Option  Certificate  to the  Option  Holder
concurrently with delivery of the aforesaid share certificate for the balance of
Shares available under the Option.

4.3      CONDITION OF ISSUE

The issue of Shares by the  Company  pursuant  to the  exercise  of an Option is
subject to this Plan and compliance with the laws,  rules and regulations of all
regulatory bodies applicable to the issuance and distribution of such Shares and
to the listing  requirements  of any stock  exchange or  exchanges  on which the
Shares may be listed.  The Option  Holder  agrees to comply  with all such laws,
rules and  regulations  and agrees to furnish to the  Company  any  information,
report and/or  undertakings  required to comply with and to fully cooperate with
the Company in complying with such laws, rules and regulations.

                                       5
<PAGE>

                                    ARTICLE 5
                            STOCK APPRECIATION RIGHTS

5.1      STOCK APPRECIATION RIGHTS

Any Option granted under the Plan may include a stock appreciation right, either
at the time of grant or by adding it to an existing Option; subject, however, to
the  grant  of such  stock  appreciation  right  being  in  compliance  with the
applicable  regulations and policies of The Toronto Stock Exchange (or any other
exchange or exchanges on which the Shares are then traded).

5.2      STOCK APPRECIATION RIGHTS TIED TO OPTIONS

Stock  appreciation  rights which may be granted  pursuant to this Plan shall be
exercisable to the extent,  and only to the extent,  the Option with which it is
included is exercisable.  To the extent that a stock appreciation right included
in or attached to an Option granted hereunder is exercised,  the Option to which
it is included or attached  shall be deemed to have been  exercised to a similar
extent.

5.3      TERMS OF STOCK APPRECIATION RIGHTS

A stock  appreciation  right  granted  pursuant  to this Plan shall  entitle the
Option Holder to elect to surrender to the Company,  unexercised,  the Option to
which it is included, or any portion thereof, and to receive from the Company in
exchange  therefor  that  number of Shares,  disregarding  fractions,  having an
aggregate  value equal to the excess of the value of one Share over the purchase
price per Share specified in such Option,  times the number of Shares called for
by the Option, or portion thereof, which is so surrendered. The value of a Share
for these  purposes,  unless  otherwise  specified or  permitted  by  applicable
regulatory  policies,  shall  be  the  weighted  average  trading  price  of the
Company's  Shares on The Toronto Stock Exchange (or, if the Shares are no longer
listed for trading on The Toronto Stock  Exchange,  then such other  exchange or
quotation system on which the Shares are listed or quoted for trading) for the 5
trading days  immediately  preceding the date the notice provided for in section
4.1 hereof is received by the Company.

5.4      EXERCISE OF STOCK APPRECIATION RIGHTS

Subject  to the  provisions  of the Plan,  a stock  appreciation  right  granted
hereunder  may be exercised  from time to time by  delivering to the Company the
Exercise Notice.


                                    ARTICLE 6
                                 ADMINISTRATION

6.1      ADMINISTRATION

The Plan shall be administered by the  Administrator  on the instructions of the
Board.  The Board may make,  amend and  repeal at any time and from time to time
such  regulations  not  inconsistent  with the Plan as it may deem  necessary or
advisable  for the  proper  administration  and  operation  of the Plan and such
regulations  shall  form  part  of the  Plan.  The  Board  may  delegate  to the
Administrator  or  any  Director,  officer  or  employee  of  the  Company  such
administrative duties and powers as it may see fit.


                                       6
<PAGE>

6.2      INTERPRETATION

The  interpretation  by the Board of any of the  provisions  of the Plan and any
determination by it pursuant thereto shall be final and conclusive and shall not
be subject to any  dispute by any Option  Holder.  No member of the Board or any
person acting  pursuant to authority  delegated by it hereunder  shall be liable
for any action or  determination  in  connection  with the Plan made or taken in
good faith and each member of the Board and each such  person  shall be entitled
to  indemnification  with  respect to any such  action or  determination  in the
manner provided for by the Company.


                                    ARTICLE 7
                            AMENDMENT AND TERMINATION

7.1      PROSPECTIVE AMENDMENT

The Board may from time to time amend the Plan,  subject to the  approval of The
Toronto Stock Exchange, and the terms and conditions of any Option thereafter to
be granted and, without limiting the generality of the foregoing,  may make such
amendment  for the purpose of meeting any changes in any relevant  law,  rule or
regulation  applicable  to the Plan,  any  Option or the Shares or for any other
purpose  which may be  permitted  by all relevant  laws,  rules and  regulations
provided  always that any such amendment shall not alter the terms or conditions
of any Option or impair any right of any Option  Holder  pursuant  to any Option
awarded prior to such amendment.

7.2      RETROSPECTIVE AMENDMENT

The Board may from time to time  retrospectively  amend the Plan, subject to the
approval of The Toronto  Stock  Exchange  and,  with the consent of the affected
Option  Holders,  retrospectively  amend the terms and conditions of any Options
which have been theretofore granted.

7.3      TERMINATION

The Board may  terminate  the Plan at any time  provided  that such  termination
shall not alter the terms or conditions of any Option or impair any right of any
Option  Holder  pursuant  to any  Option  awarded  prior  to the  date  of  such
termination and  notwithstanding  such  termination  the Company,  such Options,
Option Holders, Directors and Employees and Shares shall continue to be governed
by the provisions of the Plan.

7.4      AGREEMENT

The Company  and every  person to whom an Option is awarded  hereunder  shall be
bound by and subject to the terms and conditions of the Plan.


                                    ARTICLE 8
                           APPROVALS REQUIRED FOR PLAN

8.1      APPROVALS REQUIRED FOR PLAN

Prior to its implementation by the Company,  the Plan is subject to approvals by
the  shareholders  of the Company at a general  meeting  and The  Toronto  Stock
Exchange.


                                       7
<PAGE>

8.2      SUBSTANTIVE AMENDMENTS TO PLAN

Subject to Article 7 hereof,  any  substantive  amendments  to the Plan shall be
subject to the Company first obtaining the approvals of the  shareholders of the
Company at a general  meeting and any stock  exchange on which the Shares may be
listed for trading.




                                       8
<PAGE>

                                  SCHEDULE "A"

                        GENSCI REGENERATION SCIENCES INC.

                                STOCK OPTION PLAN
                               OPTION CERTIFICATE


This Certificate is issued pursuant to the provisions of the GenSci Regeneration
Sciences  Inc.  (the  "Company")  Amended and  Restated  Stock  Option Plan (the
"Plan")  and  evidences  that is the  holder of an option  (the  "Option")  [and
applicable  stock  appreciation  rights] to  purchase  up to common  shares (the
"Shares")  in the  capital of the  Company  at a purchase  price of $ per Share.
Subject to the provisions of the Plan:

         (a) the Award Date of this Option is________________ ; and

         (b) the Expiry Date of this Option is_______________ .


Except as provided below, this Option may be exercised at any time and from time
to time from and  including  the Award Date through to and  including up to 5:00
local time in Vancouver, British Columbia on the Expiry Date, by delivery to the
Administrator of the Plan an Exercise Notice,  in the form provided in the Plan,
together with this  Certificate and a certified  cheque or bank draft payable to
GenSci  Regeneration  Sciences  Inc. in an amount equal to the  aggregate of the
Exercise Price of the Shares in respect of which this Option is being exercised.

The right to  purchase  the Shares  will vest in  increments  over the first two
years of the Option, as follows:

------------------------------------- ----------------------------------------
                Date                              Cumulative Number
                                                     Exercisable
------------------------------------- ----------------------------------------

------------------------------------- ----------------------------------------

------------------------------------- ----------------------------------------

------------------------------------- ----------------------------------------

------------------------------------- ----------------------------------------


This Certificate and the Option evidenced hereby is not assignable, transferable
or negotiable and is subject to the detailed  terms and conditions  contained in
the Plan. This Certificate is issued for convenience only and in the case of any
dispute with regard to any matter in respect hereof,  the provisions of the Plan
and the records of the Company shall prevail.

The foregoing Option has been awarded this       day of                       .
                                           -----        ----------------------


                                      GENSCI REGENERATION SCIENCES INC.


                                      Per:
                                            -----------------------------------



                                       10
<PAGE>

                                  SCHEDULE "B"

                                 EXERCISE NOTICE

TO:               The Administrator, Stock Option Plan
                  GenSci Regeneration Sciences Inc.
                  201 - 5090 Explorer Drive
                  Mississauga, Ontario
                  L4W 4T9


1.       Exercise of Option

The  undersigned  hereby  irrevocably  gives  notice,  pursuant  to  the  GenSci
Regeneration  Sciences Inc. (the  "Company")  Amended and Restated  Stock Option
Plan  (the  "Plan"),  of the  exercise  of the  Option  to  acquire  and  hereby
subscribes for (cross out inapplicable item):

(a)      all of the Shares; or

(b)      ___________________of  the Shares  which are the  subject of the option
         certificate attached hereto.

Calculation of total Exercise Price:

(i)      number of Shares to be acquired on exercise:  ______________ shares

(ii)     times the Exercise Price per Share:          $--------------

         Total Exercise Price, as enclosed herewith:  $
                                                       ==============

The  undersigned  tenders  herewith a cheque or bank draft  (circle  one) in the
amount of  $__________________ , payable to GenSci Regeneration Sciences Inc. in
an amount equal to the total Exercise Price of the Shares,  as calculated above,
and directs the Company to issue the share certificate  evidencing the Shares in
the name of the  undersigned  to be mailed to the  undersigned  at the following
address:

          ------------------------------------

          ------------------------------------

          ------------------------------------



OR:

2. Exercise of stock appreciation right

The  undersigned  hereby  irrevocably  gives notice of the exercise of the stock
appreciation  right  provided under the Plan and  accordingly  wishes to receive

                                       11
<PAGE>

such  number  of  Shares  as  calculated   in  accordance   with  the  Plan.  As
consideration for the Shares, the undersigned hereby agrees to cancel (cross out
inapplicable item):

         (a)      all of  the  Shares  which  are  the  subject  of  the  option
                  certificate attached hereto; or

         (b)      ---------  of the Shares  which are the  subject of the option
                  certificate attached hereto.

The Company is directed to issue the share certificate  evidencing the Shares in
the name of the undersigned for mailing at the following address:

          ------------------------------------

          ------------------------------------

          ------------------------------------



All capitalized  terms,  unless otherwise defined in this exercise notice,  will
have the meaning provided in the Plan.


DATED the       day of                                            .
          -----        -------------------------------------------


------------------------------       ---------------------------------------
Witness                              Signature of Option Holder


------------------------------       ---------------------------------------
Name of Witness (Print)              Name of Option Holder (Print)


                                       12
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