<PAGE>
 
                                                                    EXHIBIT 10.6


                              DATED MARCH 24 1998
                              -------------------



                         CARDIOTECH INTERNATIONAL INC.


                                      and


                                  ALAN EDWARDS



                              EMPLOYMENT AGREEMENT
<PAGE>
 
                              EMPLOYMENT AGREEMENT
                              --------------------


PARTIES

This Employment Agreement ("the Agreement") dated the 24th day of March, 1998 is
entered into by and between

(1)  CARDIOTECH  INTERNATIONAL INC., a Massachusetts corporation having its
     principal place of business at 11 State Street, Woburn, MA 01801 ("the
     Company"), and

(2)  ALAN EDWARDS of Lianfair D.C., Ruthin Clwyd, LL15 2RU, United Kingdom ("the
     Executive")

TERMS OF AGREEMENT

In consideration of this Agreement and the continued employment of the Executive
by the Company and the payment of $1 by the Company to the Executive and the
covenants contained in the Service Agreement (as hereinafter defined) the
parties agree as follows:

1.  Employment
    ----------

    1.1.  The Company hereby agrees to employ the Executive to act as Executive
          Vice President of the Company and to perform such acts and duties and
          furnish such services to the Company in connection with and related to
          that position as is customary for persons with similar positions in
          like companies and as the Chief Executive Officer of the Company shall
          from time to time reasonably direct. The Executive shall be an officer
          of the Company.

    1.2.  The Executive hereby accepts the said employment.
<PAGE>
 
    1.3.  The Executive shall use his diligent efforts to promote the interests
          of the Company and shall discharge his duties in a competent manner.

    1.4.  The Executive shall report directly to the Chief Executive Officer of
          the Company.

    1.5.  It is acknowledged by the Company that the Executive is employed on a
          full time basis by its United Kingdom subsidiary company, CardioTech
          International Limited ("Cardio Limited") pursuant to the terms of a
          Service Agreement (the "Service Agreement") made between Cardio
          Limited and the Executive on the date hereof. The Executive is
          required to devote his full business time to Cardio Limited pursuant
          to the terms of the Service Agreement and the duties set out in this
          Agreement shall be interpreted accordingly.

2.  Term of Employment
    ------------------

    2.1.  The Company agrees to employ the Executive initially for the period
          commencing on 1st January 1998 and ending on 31st December 1998 ("the
          Employment Period') provided that both the Executive and the Company
          shall have the right to terminate the Executive's employment under
          this Agreement upon not less than thirty (30) days written notice to
          the other party, subject to the Company's obligation to pay severance
          benefits in accordance with the terms of this Agreement.

    2.2.  If the Executive remains employed by the Company beyond the Employment
          Period in the absence of any other express agreement between the
          parties this Agreement shall be deemed to continue on a month-to-month
          basis ("the Extended Employment Period").

    2.3.  For the purpose of calculating the Executive's period of continuous
          employment, the Executive's employment with Newtec Vascular Products

                                       2
<PAGE>
 
          Limited from March 1989 to August 1993, and with PolyMedica UK Limited
          from August 1993 until June 1996, shall be taken into account. The
          Executive's period of continuous employment with the Company began in
          March 1989.

3.  Salary and Benefits after Termination
    -------------------------------------

    3.1.  Salary
          ------
          During the Executive's employment, the Company shall pay the Executive
          a nominal annual salary of one US dollar ($1).

    3.2.  Disability or Death
          -------------------
          If during the Employment Period or the Extended Employment Period, the
          Executive shall

          3.2.1.  become ill, disabled or otherwise incapacitated so as to be
                  unable to perform his usual duties either for a period in
                  excess of one hundred twenty (120) consecutive days, or for
                  more than one hundred eighty (180) days in any consecutive
                  twelve (12) month period, or

          3.2.2.  die;

          then the Company shall have the right to terminate this Agreement on
          thirty (30) days written notice to the Executive or his personal
          representative(s).

    3.3.  Severance Payment
          -----------------
          3.3.1.  In the event that

                3.3.1.1.  the Company terminates this Agreement without cause
                          (i.e. other than pursuant to Clause 3.2 hereof) at any
                          time (including during the Extended Employment
                          Period); or

                                       3
<PAGE>
 
               3.3.1.2.  the Executive terminates his employment For Good Reason
                         following a Change in Control of the Company; or

               3.3.1.3.  the Company fails to renew this Agreement within two
                         (2) years following the occurrence of a Change in
                         Control;

               the Company shall pay the Executive a severance payment, equal to
               the current or last base salary paid to the Executive by Cardio
               Limited pursuant to the terms of the Service Agreement multiplied
               by 2.

       3.3.2.  "Good Reason" shall mean, during the nine (9) month period
               following a Change in Control:

               3.3.2.1.  a determination in good faith by the Executive that as
                         a result of such Change in Control he is not able to
                         discharge his duties effectively or

               3.3.2.2.  without the Executive's express written consent, the
                         occurrence of any of the following circumstances: (a)
                         the assignment to the Executive of any duties
                         inconsistent (except in the nature of a promotion) with
                         the position in the Company that be held immediately
                         prior to the Change in Control or a substantial adverse
                         alteration in the nature or status of his position or
                         responsibilities or the conditions of his employment
                         from those in effect immediately prior to the Change in
                         Control; (b) a reduction by the Company in the Base
                         Salary as in effect on the date of the Change in
                         Control; (c) the Company's requiring the Executive to
                         be based more than twenty-five (25) miles from the
                         offices at which he was principally employed
                         immediately prior to the date of the Change in Control
                         except for required travel

                                       4
<PAGE>
 
                         on the Company's business to an extent substantially
                         consistent with his present business travel
                         obligations; or (d) the failure by the Company to
                         continue in effect any material compensation or benefit
                         plan in which the Executive participates immediately
                         prior to the Change in Control unless an equitable
                         arrangement (embodied in an ongoing substitute or
                         alternative plan) has been made with respect to such
                         plan, or the failure by the Company to continue the
                         Executive's participation therein (or in such
                         substitute or alternative plan) on a basis not
                         materially less favorable, both in terms of the amount
                         of benefits provided and the level of his participation
                         relative to other participants, than existed at the
                         time of the Change in Control.

               3.3.2.3.  The Executive's continued employment shall not
                         constitute consent to, or a waiver of rights with
                         respect to any circumstance constituting Good Reason
                         hereunder.

       3.3.3.  For purposes of this Agreement, a "Change in Control" shall occur
               or be deemed to have occurred only if any of the following events
               occur:

               3.3.3.1.  any "person" as such term is used in Clauses 13(d) and
                         14(d) of the United States' Securities Exchange Act of
                         1934, as amended ("the Exchange Act"), is or becomes
                         the beneficial owner (as defined in Rule 13d-3 under
                         the Exchange Act), directly or indirectly, of
                         securities of the Company representing 50% or more of
                         the combined voting power of the Company's then
                         outstanding securities

                                       5
<PAGE>
 
                         on any matter which could come before its shareholders
                         for approval;

               3.3.3.2.  individuals who, as of the date of this Agreement,
                         constitute the Board (the "Incumbent Board") cease for
                         any reason to constitute at lease a majority of the
                         Board, provided that any person becoming a director
                         subsequent to the date hereof whose election or
                         nomination for election by the Company's shareholders,
                         was approved by a vote of at least a majority of the
                         directors then comprising the Incumbent Board shall be,
                         for purposes of this Agreement, considered as though
                         such person were a member of the Incumbent Board;

               3.3.3.3.  the shareholders of the Company approve a merger or
                         consolidation of the Company with any other company or
                         corporation, other than (A) a merger or consolidation
                         which would result in the voting securities of the
                         Company outstanding immediately prior thereto
                         continuing to represent (either by remaining
                         outstanding or by being converted into voting
                         securities of the surviving entity) more than 80% of
                         the combined voting power of the voting securities of
                         the Company or such surviving entity outstanding
                         immediately after such merger or consolidation or (B) a
                         merger or consolidation effected to implement a re-
                         capitalisation of the Company (or similar transaction)
                         in which no "person" (as herein above defined) acquires
                         more than 50% of the combined voting power of the
                         Company's then outstanding securities; or

                                       6
<PAGE>
 
               3.3.3.4.  the shareholders of the Company approve a plan of
                         complete liquidation of the Company or an agreement for
                         the sale or disposition by the Company of all or
                         substantially all of the Company's assets.

       3.3.4.  The Company shall not be liable to pay the Executive a severance
               payment pursuant to the terms set out herein if a severance
               payment has been paid to the Executive pursuant to the terms of
               the Service Agreement.

3.4.  Benefits After Termination
      --------------------------

       3.4.1.  Other than as required at law, the Executive shall not be
               entitled to any employee benefits pursuant to the terms of this
               Agreement after termination of the employment of the Executive,
               whether or not severance pay is being provided, except that if
               the Executive is entitled to the severance payment pursuant to
               the terms of this Agreement.

               3.4.1.1. the Company shall continue in full force and effect, at
                        its expense, life insurance provided pursuant to the
                        terms of the Service Agreement for a period of one (1)
                        year after termination of the Executive's employment
                        hereunder or until the Executive becomes employed,
                        whichever first occurs; and

               3.4.1.2. during the six (6) month period following the
                        termination of the Executive's employment, the Company
                        shall reimburse the Executive for out-of-pocket health
                        insurance expenses incurred by the Executive. If the
                        Executive elects not to maintain health insurance, the
                        Company is under no

                                       7
<PAGE>
 
                        obligation to reimburse the Executive for his otherwise
                        elected coverage.

              3.4.1.3.  the Executive shall be obliged to give the Company
                        prompt notice of his re-employment.

      3.4.2.  The Company shall not be liable to pay the Executive benefits
              pursuant to the terms set out herein if a severance payment has
              been paid to the Executive pursuant to the terms of the Service
              Agreement.

4.  Expenses
    --------

    Pursuant to the Company's customary policies in force at the time of
    payment, the Executive shall be promptly reimbursed, against presentation of
    vouchers or receipts therefor, for all authorised expenses properly incurred
    by him on the Company's behalf in the performance of his duties hereunder.

5.  Additional Agreements
    ---------------------

    Upon execution of this Agreement, the Executive shall execute and deliver
    to the Company an Agreement Not to Compete (the "Non-Competition
    Agreement") and a Confidential and Proprietary Information Agreement (the
    "Confidential and Proprietary Information Agreement"), substantially in the
    forms attached hereto as Schedules A and B. The agreements attached hereto
    as Schedules A and B shall survive the expiration of or termination of this
    Agreement and the termination of Executive's employment with the Company.

6.  Notices
    -------

    Any notice of communication given by either party hereto to the other party
    shall be in writing and personally delivered, posted by recorded delivery,
    postage prepaid, or delivered by a recognised overnight carrier, to the
    addresses provided

                                       8
<PAGE>
 
    above. All notices shall be deemed given when actually received. My person
    entitled to receive notice (or a copy thereof) may designate in writing, any
    notice to the others, another address to which notices to such person shall
    thereafter be sent.

7.  Miscellaneous
    -------------

    7.1.  Entire Agreement
          ----------------

          This Agreement contains the entire understanding of the parties in
          respect of its subject matter and supersedes all prior agreements and
          understandings between the parties with respect to such subject
          matter, provided however that nothing in this Agreement shall affect
          the Executive's or the Company's obligations under the Non Competition
          Agreement or the Confidential and Proprietary Information Agreement
          attached as Schedules A and B nor shall anything contained herein
          affect the respective obligations of the Executive and Cardio Limited
          in the Service Agreement.

    7.2.  Amendment: Waiver
          -----------------

          This Agreement may not be amended. supplemented, cancelled or
          discharged except by written instrument executed by the party affected
          thereby No failure to exercise, and no delay in exercising, any right,
          power or privilege hereunder shall operate as a waiver thereof. No
          waiver of any breach of any provision of this Agreement shall be
          deemed to be a waiver of any preceding or succeeding breach of the
          same or any other provisions.

    7.3.  Binding Effect: Assignment
          --------------------------

          The rights and obligations of this Agreement shall bind and inure to
          the benefit of any successor of the Company by reorganisation, merger
          or consolidation or any assignee of all or substantially all of the
          Company's 

                                       9
<PAGE>
 
          business and properties. The Executive's rights or obligations under
          this Agreement may not be assigned by the Executive.

    7.4.  Headings
          --------

          The headings contained in this Agreement are for reference purposes
          only and shall not affect the meaning or interpretation of this
          Agreement.

    7.5.  Governing Law: Interpretation
          -----------------------------

          This Agreement shall be construed in accordance with and governed for
          all purposes by the laws and public policy of the Commonwealth of
          Massachusetts applicable to contracts executed and to be wholly
          performed within such commonwealth. Service of process in any dispute
          shall be effective (a) upon the Company, if service is made on an
          officer of the Company other than the Executive; (b) upon the
          Executive, if served at the Executive's residence last known to the
          Company with an information copy to the Executive at any other
          residence, or in care of a subsequent employer of which the Company
          may be aware.

    7.6.  Further Assurances
          ------------------

          Each of the parties agrees to execute, acknowledge, deliver and
          perform, or cause to be executed, acknowledged, delivered or
          performed, at any time, or from time to time, as the case may be, all
          such further acts, deeds, assignments, transfers, conveyances, powers
          of attorney, and assurances as may be necessary or proper to carry out
          the provisions or intent of this Agreement.

    7.7.  Severability
          ------------

          If any one or more of the terms, provisions, covenants or restrictions
          of this Agreement shall be determined by a court of competent
          jurisdiction in the United State to be invalid, void or unenforceable,
          the remainder of the terms, provisions, covenants and restrictions of
          this Agreement shall

                                       10
<PAGE>
 
          remain in full force and effect and shall in no way be affected,
          impaired or invalidated. If, moreover, any one or more of the
          provisions contained in this Agreement shall for any reason be
          determined by a court of competent jurisdiction in the United States
          to be excessively broad as to duration, geographical scope, activity
          or subject, it shall be construed by limiting or reducing it so as to
          be enforceable to the extent compatible with then applicable law.

                                   EXECUTION
                                   ---------

The parties executed this Agreement as a sealed instrument as of the date first
above written, whereupon it became binding in accordance with its terms.

                              CARDIOTECH INTERNATIONAL INC.



                              By:
                                 -----------------------------------------
                                                     Michael Szycher, Ph.D.
                                                     Chairman of the Board

                                                                  EXECUTIVE


                              By:
                                 -----------------------------------------
                                                              Alan Edwards

Attachments:

Exhibit A:           Non-competition Agreement
---------                                                 
Exhibit B:           Confidential and Proprietary Information Agreement 
---------                                                                

                                       11
<PAGE>
 
                                   SCHEDULE A

                            AGREEMENT NOT TO COMPETE
                            ------------------------

I recognise that CardioTech International Inc., a Massachusetts corporation
having its principal place of business at 11 State Street, Woburn, MA 01801 (the
"Company" which term shall include its subsidiaries and affiliated entities)
desires to retain me in its employ and that the Company wishes to ensure that I
do not compete with the Company, as specified below, in the event my employment
with the Company is terminated.

In consideration of the Company's employment or continued employment of me, I
agree as follows:

1.   I will not, for a period of one (1) year commencing with the termination of
     my employment with the Company, engage (directly or indirectly) in any
     activities or render any services similar or reasonably related to these in
     which I shall be engaged or those reasonably related to those in which I
     shall have engaged or those which I shall have rendered as an employee of
     the Company during any part of the two year period preceding my termination
     for any trade or business which directly competes with the Company in any
     place where the Company does or may do business in any line of business
     engaged in (or planned to be engaged in) by the Company, where now existing
     or hereafter established, nor shall I engage in such activities nor render
     such services for any other person or entity engaged or about to become
     engaged in such activities to, for or on behalf of any such trade or
     business.

2.   I agree that for a period of one (1) year following termination of my
     employment with the Company, I will not solicit or in any manner encourage
     employees of the Company to leave their employ. I further agree that during
     such period I will not offer or cause to be offered employment to any
     person who was employed by the Company at any time during the six (6)
     months prior to the termination of my employment with the Company.

                                       12
<PAGE>
 
3.   For the purposes of this Agreement, "termination of employment" shall mean
     voluntary termination by me or termination by the Company for "Cause" (as
     that term is defined in a Service Agreement of even date herewith between
     me and CardioTech International Inc.).

4.   I understand that nothing in this Agreement shall affect my obligations
     under the "Confidential and Proprietary Information Agreement" between the
     Company and myself of even date herewith.

5.   I understand that in addition to any other rights and remedies available to
     the Company for any breach by me of my obligations hereunder, the Company
     shall be entitled to seek enforcement of my obligations hereunder by court
     injunction.

6.   If any provision of this Agreement shall be declared invalid, illegal or
     unenforceable by a court of competent jurisdiction in the United States,
     then such provision shall be enforceable to the extent that such court
     shall deem it reasonable to enforce such provision. If such provision shall
     be unreasonable to enforce to any extent, such provision shall be severed
     from this Agreement and all remaining provisions shall continue in full
     force and effect.

7.   This Agreement shall be governed in all respects by the Laws of the
     Commonwealth of Massachusetts.

IN WITNESS WHEREOF I have executed this Agreement.

                                         Date
---------------------------------            ------------------
Alan Edwards

                                       13
<PAGE>
 
ACCEPTED AND AGREED TO:
CardioTech International Inc.

By:                                               Date
   ------------------------------------------         ------------------
   Michael Szycher. Ph.D.
   Chairman of the Board

                                       14
<PAGE>
 
                                   SCHEDULE B

                                 FOR EMPLOYEES
                                 -------------
              CONFIDENTIAL AND PROPRIETARY INFORMATION AGREEMENT
              --------------------------------------------------

In consideration of my employment by CardioTech International Inc. a
Massachusetts corporation having its principal place of business at 11 State
Street, Woburn, MA 01801 (the "Company"), which term shall include its
subsidiaries and affiliated entities), I hereby agree as follows:

1.   I will make full and prompt disclosure to the Company of all inventions,
     improvements, modification, discoveries, methods, data, ideas and
     developments (all of which are collectively termed "Developments"
     hereinafter), whether patentable or not, made or conceived or reduced to
     practice or learned by me either alone or jointly with others or under my
     direction during the period of my employment, whether or not made or
     conceived during normal working hours or on the premises of the Company. I
     do not have any Developments other than those I have already disclosed to
     the Company.

2.   I agree that all Developments covered by paragraph 1 shall be the sole
     property of the Company and its assigns, and the Company and its assigns
     shall be the sole owner of all patents and other rights in connection
     therewith. I hereby assign to the Company any rights in connection
     therewith. I hereby assign to the Company any rights I may have or acquire
     in all Developments.  I further agree as to all Developments to assist the
     Company in every proper way (but at the Company's expense) to obtain and
     from time to time enforce patents in Developments in any and all countries,
     and to that end I will execute all documents for use in applying for and
     obtaining such patents thereon and enforcing same as the Company may
     desire, together with any assignments thereof to the Company or persons
     designated by it.  My obligation to assist the Company in obtaining and
     enforcing patents for Developments in any and all countries shall continue
     beyond the termination of my employment, but the Company shall compensate
     me at a

                                       15
<PAGE>
 
     reasonable rate after such termination for time actually spent by me at the
     Company's request on such assistance.

     I understand that this paragraph 2 does not apply to Developments for which
     no equipment, supplies, facility or trade secret information of the Company
     was used and which were developed entirely on my own time, and (a) which do
     not relate (1) to the business of the Company or (2) to the Company's
     actual or demonstrable anticipated research or Development, and (b) which
     do not result from any work performed by me for the Company, but I agree
     that the Company shall have a non-exclusive royalty free license to use
     such Developments for all purposes.

3.   I hereby represent that, to the best of my knowledge, I have no present
     obligation to assign to any former employer or any other person,
     corporation or firm, any Development covered by paragraph 2. I represent
     that my performance of all the terms of this Agreement as an employee of
     the Company does not and will not breach any agreement to keep in
     confidence proprietary information acquired by me in confidence or in trust
     prior to my employment by the Company. I have no entered into, and I agree
     I will not enter into, any agreement (either written or oral) in conflict
     herewith.

4.   I will also assign to the Company and all copyrights and reproduction
     rights to any material prepared by me in connection with my employment.

5.   I understand as part of the consideration for the offer of employment
     extended to me by the Company and of my employment or continued employment
     by the Company that have not brought and will not bring with me to the
     Company or use in the performance of my responsibilities at the Company any
     materials or documents of a former employer which are not generally
     available to the public, unless I have obtained written authorisation from
     the former employer for their possession and use.

                                       16
<PAGE>
 
6.   During the course of my employment by the Company, I may learn of the
     Company's confidential information or confidential information entrusted to
     the Company by other persons, corporations, or firms. The Company's
     confidential information includes matters not generally known outside the
     Company, such as Developments relating to existing and future products and
     services marketed or used by the Company and data relating to the general
     business operations of the Company (e.g. concerning sales, costs, profits,
     organisations, customer lists, pricing methods etc.). I agree not to
     disclose any confidential information of the Company or of such other
     persons, corporations, or firms to others or to make use of it, except on
     the Company's behalf, whether or not such information is produced by my own
     efforts. Also, I may learn of Developments, ways of business, etc. which in
     themselves are generally known, but whose use by the Company is not
     generally known, and I agree not to disclose to other such use, whether or
     not such use is due to my own efforts.

7.   At the time I begin my employment and during the term of my employment by
     the Company, I will not become employed by or act on behalf of any other
     person, company, or firm which is engaged in any business or activity
     similar to or competitive with that of the Company, unless such employment
     has been approved by the Company in writing and signed by an appropriate
     authorised official of the Company.

8.   In the event that my employment is transferred by the Company to a
     subsidiary or affiliated company (as the case may be), my employment by
     such company will, for the purposes of this Agreement, be considered as
     continued employment by the Company, unless I execute an agreement
     substantially similar in substance to this Agreement, in which event my
     employment by the Company shall be deemed to continue until the effective
     date of said agreement in any such company for which I become employed.

                                       17
<PAGE>
 
9.   I hereby give the Company and its assigns permission to reasonably use
     photographs of me, either during or after my employment, with or without
     using my name, for whatever purposes it deems necessary.

10.  Upon termination of my employment, unless my employment is transferred to a
     subsidiary or affiliated company of the Company, I agree to leave with the
     Company all records, drawings, notebooks and other documents pertaining to
     the Company's confidential information, whether prepared by me or others,
     and also any equipment, tools or other devices owned by the Company, then
     in my possession however such items are obtained, and I agree not to
     reproduce any document or data relating thereto.

11.  My obligations under this Agreement shall survive the termination of my
     employment regardless of the manner of such termination, and shall be
     binding upon my heirs, executors, and administrators.

12.  Contemporaneously with entering thc employ of the Company I have terminated
     employment with all past employers.

13.  I represent that I have made no Developments relevant to the subject matter
     of my employment by the Company that have been made or conceived or first
     reduced to practice by me alone or jointly with others prior to my
     engagement by the Company.

14.  I agree that in addition to any other rights and remedies available to the
     Company for any breach by me of my obligations hereunder, the Company shall
     be entitled to seek enforcement of my obligations hereunder by court
     injunction.

15.  If any provision of this Agreement shall be declared invalid, illegal or
     unenforceable by a court of competent jurisdiction in the United States,
     then such provision shall be enforceable to the extent that such court
     shall deem it reasonable to enforce such provision. If such provision shall
     be unreasonable to

                                       18
<PAGE>
 
     any extent, such provision shall be severed from this Agreement and all
     remaining provisions shall continue in full force and effect.

16.  This Agreement shall be effective as of the date set forth below next to my
     signature.

17.  This Agreement shall be governed in all respects by the laws of the
     Commonwealth of Massachusetts.

IN WITNESS WHEREOF I have executed this Agreement.

/s/ Alan Edwards
-----------------------------------
Alan Edwards

ACCEPTED AND AGREED TO:
CardioTech International, Ltd.

By: /s/ Michael Szycher                  Date  March 24, 1998  
        -------------------------                                              
        Michael Szycher. Ph.D.
        Chairman of the Board

                                       19