Ex.  10.56


                             [CardioTech Letterhead}




                                                    October 10, 2001


Implant  Sciences  Corporation
107  Audubon  Road
Wakefield, Massachusetts 01880-1246

Ladies  and  Gentlemen:

          We  are pleased to confirm that we are extending to you ("Borrower") a
line  of  credit  of  up to an aggregate amount of $500,000 (the "Credit Line"),
subject to the terms and provisions, and on the conditions, set forth herein and
in  the  other  documents  entered  into  in  connection  with  the Credit Line.

          1.     The  Credit  Line
                 -----------------

          Borrowings  under  this  Credit Line shall be evidenced by a grid note
(the  "Note"),  a  copy  of  which  is attached hereto as Exhibit A.  Under this
Credit  Line,  borrowings may be made from time to time in the minimum amount of
$25,000  and  shall  be  repayable  in  full  on October 12, 2002 (the "Maturity
Date"), but may be prepaid at any time in whole or in part with accrued interest
to  the  date  of  prepayment.  You  may  request  borrowings  hereunder only in
compliance  with  all  the  terms and conditions hereof and you may not make any
borrowings hereunder after the Maturity Date.  The aggregate amount that you may
borrow under the Credit Line is $500,000.  Any amounts borrowed and repaid prior
to  the Maturity Date may not be reborrowed.  Any amounts outstanding shall bear
interest,  payable  monthly in arrears, at a variable rate per annum equal to 2%
above the Prime Rate set forth in the Wall Street Journal from time to time, all
as  more  fully  set  forth  in  the  Note.


<PAGE>
          The  Credit  Line  shall  be  secured  by  a second priority lien (the
"Credit  Line  Lien")  on  all  of  the  personal  property  and fixtures of the
Borrower,  whether  tangible  or  intangible, including, without limitation, all
accounts  receivable,  goods, equipment, inventory, intellectual property, trade
secrets,  formulae,  processes,  software and general intangibles (including tax
refunds),  all  as more fully set forth in the security agreement (the "Security
Agreement")  attached  hereto as Exhibit B.  The Credit Line Lien will be second
in  priority  only  to  Citizens Bank (the "Existing Lender") and only to secure
debt  no  greater  than  the  principal  amount  of  $367,650.00.   All  of your
obligations  under  this  Credit  Line  shall be guaranteed by Anthony J. Armini
("Guarantor")  pursuant  to  the  guarantee  (the "Guarantee" attached hereto as
Exhibit C.  In addition, the holders of other debt of the Borrower identified on
Schedule  D-1  will  execute  and  deliver  to us a subordination agreement (the
"Subordination  Agreement"  and  together  with  this Line of Credit Letter, the
Note,  the  Security  Agreement  and the Guarantee, sometimes referred to herein
collectively  as  the  "Loan  Documents" and each a "Loan Document") in the form
attached  hereto  as  Exhibit  D.

          2.     Conditions,  Representations  and  Warranties,  and  Covenants
                 --------------------------------------------------------------

          The  Line  of  Credit  may be utilized by you for a period of one year
ending  on  October  12, 2002; provided, however, THE CONTINUING AVAILABILITY OF
                               -----------------
THIS  LINE  OF CREDIT IS AT ALL TIMES SUBJECT TO YOUR COMPLIANCE WITH THE TERMS,
PROVISIONS  AND CONDITOINS OF EACH LOAN DOCUMENT.  WE HAVE NO OBLIGATION TO MAKE
ANY  ADVANCE  TO YOU UPON THE OCCURRENCE OF ANY DEFAULT UNDER ANY LOAN DOCUMENT.
In  addition,  the continuing availability of the Credit Line is subject to your
furnishing  us with such financial statements as you provide the Existing Lender
at  the  time  you  provide such financial statements to the Existing Lender and
such  other information, including interim financial statements, concerning your
business,  affairs  or  financial condition as we may from time to time request.

          All payments of principal, interest and fees payable by you under this
Credit  Line  shall  be made in immediately available funds at our office at78-E
Olympia  Avenue,  Woburn,  MA  01801.

          (a)  Representations and Warranties.

               To  induce  us  to make the advances described herein, you hereby
represent  and  warrant  to  us  as  follows:

               (i)  Borrower  (A)  is  a  corporation  duly  organized, validly
existing  and  in  good  standing  under  the  laws  of  the  Commonwealth  of
Massachusetts,  (B)  has  all requisite corporate power and authority to execute
and  deliver  the  Loan  Documents  to  which it is a party and to carry out the
transactions  and  perform  its  obligations contemplated thereby and to own its


                                        2
<PAGE>
properties  and  carry  out  its  business  as  presently conducted, (C) is duly
qualified  as  a  foreign  corporation and is in good standing in such states or
jurisdictions  in  which  the  business  conducted by it and the location of its
assets require it to qualify as a foreign corporation, and (D) has all necessary
licenses,  authorizations,  registrations,  permits  and  approvals  to  own its
properties  and  carry  on  its  business  as  presently  conducted;

               (ii)     The  execution  and  delivery by Borrower of each of the
Loan  Documents to which it is a party and the performance by Borrower of all of
its  obligations  thereunder  (i)  have  been  duly  authorized by all necessary
corporate  action  on  the  part of the Borrower, (ii) will not violate or be in
conflict  with  (a)  any  provisions  of  any  applicable  law,  statute,  code,
regulation  or  rule  (including  without  limitation,  any  applicable usury or
similar  law), (b) any order, rule or regulation of any court or other agency of
government,  or (c) any provision of the Articles of Incorporation or By-Laws of
Borrower,  (iii) will not violate, be in conflict with, or result in a breach of
or  constitute  (with  or without the giving of notice or the passage of time or
both)  a default under any material indenture, agreement, or other instrument to
which  Borrower  is  a  party  or  by which Borrower or any of its properties or
assets  are  or  may  be bound, and (iv) except as otherwise contemplated by the
Loan  Documents,  will  not  result  in  the creation or imposition of any lien,
charge  or  encumbrance  upon,  or  any  security interest in, any of Borrower's
properties  or  assets.;

               (iii)     There is no pending or threatened, action or proceeding
(whether  before  any  court,  governmental  agency, tribunal or arbitration, or
otherwise)  affecting Borrower or Guarantor that may materially adversely affect
the  condition  (financial or otherwise) of any of such parties or that purports
to  affect the legality, validity or enforceability of any of the Loan Documents
except  as  set  forth  in  Schedule  E  hereto;  and

               (iv)     The  audited  income statement for the 12 months ending,
and  the  balance  sheet  dated  as of,  June 30, 2000, and the unaudited income
statement  for  the  nine months ended, and the balance sheet dated as of, March
31,  2001  (together  the  "Financial  Statements"),  have  been  prepared  in
compliance  with  generally  accepted  accounting  principals,  applied  on  a
consistent basis, are true and correct as of such dates and for such periods, do
not fail to disclose any material liabilities of the Borrower, and there has not
occurred  any  material adverse effect upon the business or condition (financial
or  otherwise)  of  the  Borrower  since  March  31,  2001.

               (v)     The  Borrower  and  the  Guarantor have duly executed and
delivered each of the Loan Documents to it or he is a party, as the case may be.
Each  of  the  Loan Documents constitutes a legal, valid and binding instrument,
enforceable  against  Borrower  and Guarantor (if a party to the applicable Loan
Document)  in  accordance  with  its  terms.


                                        3
<PAGE>
               (vi)     No  (A)  consent,  approval  or  authorization  of,  or
registration,  declaration  or  filing  with  any governmental authority, or (B)
consent, approval or authorization (other than from Citizens Bank is required is
required  from  any other person or entity, in connection with or as a condition
precedent  to  the due and valid execution and delivery by Borrower or Guarantor
of  the  Loan  Documents  to  which it or he is a party, as the case may be, the
performance  of  each  of  their  respective  obligations  thereunder, or to the
legality,  validity, binding effect, performance or enforceability of any of the
respective  terms,  provisions  or  conditions  thereof.

               (vii)     The  Borrower  has  not  created,  incurred, assumed or
caused  to exist any lien on any of its assets, except for to the existing liens
in  favor  of  the  Existing Lender securing the indebtedness of Borrower to the
Existing  Lender  under  a  certain term loan facility in the original principal
amount  of $750,000 of which $367,650 is outstanding as of the date hereof (such
loan  in  the  principal  amount  not  to  exceed $367,650).  Borrower shall not
without  our  prior written approval directly or indirectly make, create, incur,
assume  or  permit  to  exist  any  assignment, lien, pledge, mortgage, security
interest  or other lien or encumbrance of any nature in, to or own or acquire or
agree  to acquire any property of any character to be included in the collateral
subject  to  any  of the foregoing encumbrances, except for the lien in favor of
the  Existing  Lender  described  above,  and  the  Borrower  will  not, without
obtaining  our  prior  written  approval, sign, file or authorize the signing or
filing  of  a  financing  statement  under  the  Uniform  Commercial Code of any
jurisdiction  within  the  United  States.

          (b)     Covenants.

               Until the Maturity Date, the Borrower hereby covenants and agrees
with  us  as  follows:

               (i)     To  maintain  its  existence  as  a  validly  existing
corporation  under  the  law  of  the  Commonwealth  of  Massachusetts;

               (ii)     To  comply  with  all terms, provisions and covenants of
its  agreements  with  the  Existing  Lender  and  not  to  permit  any  default
thereunder;

               (iii)     Not  to  incur any additional indebtedness for borrowed
money  other  than  that  which  exists  as  of  June  30,  2001;

               (iv)     Unless  contested  in  good  faith  and  by  appropriate
proceeding,  promptly pay when due all lawful claims and taxes which, if unpaid,
might  become  a  lien  or  charge  on  its  or  his  property  or  assets;


                                        4
<PAGE>
               (v)     Not  to  incur,  create,  assume  or  suffer to exist any
mortgage,  pledge,  lien,  security interest, charge or other encumbrance of any
nature  whatsoever  on the Collateral other than in our favor or in favor of the
Existing  Lender;  and

               (vi)     To  comply  with  all terms, provisions and covenants of
each  Loan  Document.

          (c)     Conditions  Precedent.

          You hereby agree to pay, upon the execution of this Credit Line Letter
and thereafter on demand, all of our attorneys' fees we incur in connection with
the  Credit  Line, each and every borrowing hereunder, and any administration or
enforcement  of  any  Loan  Document  or  our  rights  or remedies thereunder or
hereunder.  Further, you will pay to us a fee (the "Line Fee") equal to $15,000,
which  Line  Fee is payable on the earlier to occur of (a) April 10, 2002 or (b)
your  first  borrowing  under  the Credit Line.  The foregoing payments that you
hereby  agree  to  pay  us  are  both your covenant to us and a condition to our
advancing any funds to you under the Credit Line.  In addition, our agreement to
extend  to  you  this  Credit  Line,  on  the terms set forth herein, is further
subject  to  and  conditioned  upon,  your delivering to us, at or prior to your
first  borrowing  (and  where  indicated,  to be given to us at the time of each
borrowing),  the  following:

          (i)  the Note, executed and delivered by an authorized officer of your
company;

          (ii)  a  certificate, in the form attached as Exhibit F hereto, signed
by  an  authorized  officer  of  your  company,  (A)  restating  all  of  the
representations  and  warranties set forth herein as if each such representation
and  warranty  were  made  as of the date of each such borrowing, (B) certifying
that  all  such  representations and warranties are true as of such date and (C)
certifying  that  the  Borrower has complied with all obligations under all Loan
Documents,  and  there  does  not exist any default hereunder or under any other
Loan  Document,  Existing  Lender  Document,  or any other agreement between the
Borrower  (or  any  of  its  affiliates) and us (or any of our affiliates), such
agreement  being  sometimes  referred  to  herein  as  a  "Borrower  Agreement";

          (iii)  the  Security Agreement executed and delivered by an authorized
officer,  together  with  copies  of  such  UCC  financing  statements as we may
require, and any amendments thereto which may, in the opinion of our counsel, be
desirable  or  necessary in order to fully perfect the security interests in the
collateral  granted  therein  (including,  without  limitation,  any  and  all
intellectual property) with any and all governmental offices (including, without
limitation,  the  U.S.  Patent  and  Trademark  Office);


                                        5
<PAGE>
          (iv)  the  Guarantee  signed  by  the  Guarantor;

          (v)  a legal opinion, delivered by legal counsel reasonably acceptable
to  us,  in  the  form  attached  hereto  as  Exhibit  F;

          (vi)  our  receipt  in  form satisfactory to us of a certified copy of
resolutions  of your Board of Directors authorizing your execution, delivery and
performance  of  this  agreement  and  the Loan Documents to be executed by your
company  and  a certified copy of the articles of incorporation of your company,
certified  by the Secretary of State of the jurisdiction of its incorporation as
of  a  date  no  less  than  three days prior to the date of the first borrowing
hereunder,  and  a  Certificate  of  Good  Standing  of  Borrower  issued by the
Secretary of State of the jurisdiction of organization as of a date no less than
three  days  prior  to  the  date  of  the  first  borrowing  hereunder;

          (vii)  our  receipt  of  any  and all documents, instruments and other
filings duly executed by Borrower and Guarantor which may, in the opinion of our
counsel,  be  desirable  or  necessary  to  fully perfect the security interests
granted  by  Borrower  to  secure  the  indebtedness  hereunder.

          Further, without limiting the generality of anything contained herein,
it  is  a condition precedent to our making any advances to you under the Credit
Line  that on the date of each advance which the Borrower requests, that (x) all
of  the  Borrower's  representations  and warranties made herein or in any other
Loan  Document,  and in any agreement or instrument between the Borrower and the
Existing Lender (an "Existing Lender Agreement"), be true and correct as of such
date,  (y) that the Borrower has complied with all of its covenants made herein,
in any other Loan Document and any Existing Lender Agreement and (z) there shall
not  have  occurred  any  default  hereunder, in any other Loan Document, in any
Existing  Lender  Agreement  or  under  any  Borrower  Agreement.

          3.     Borrowing  Requests.
                 -------------------

          In  the  event  that  the  Borrower  desires  to  request  a borrowing
hereunder, the Borrower will submit its request, in writing, at least 10 days in
advance  of  the  date on which the borrowing is requested, to us at the address
set forth above (or such other address as we designate in writing to Borrower at
its  address  above),  to  the  attention of Michael Szycher.  Such request will
state  the  amount of such request, the date that the advance is requested to be
made,  the  account  in  a commercial bank located in the United States that the
Borrower requests that we wire transfer the funds (together with complete wiring
instructions), together with all items required pursuant hereto.  By making such
request,  the Borrower is authorizing us to (a) deduct from any such advance any


                                        6
<PAGE>
and  all  amounts  owed by the Borrower to us, hereunder or otherwise and (b) to
make  an  appropriate  entry  on  the  Note  of  such  borrowing.

          NO  AMENDMENT, MODIFICATION OR WAIVER OF ANY PROVISION OF THIS LINE OF
CREDIT  LETTER NOR CONSENT TO ANY DEPARTURE BY US FROM THE TERMS HEREOF SHALL BE
EFFECTIVE,  IRRESPECTIVE  OF  ANY COURSE OF DEALING, UNLESS THE SAME SHALL BE IN
WRITING AND SIGNED BY US AND THEN SUCH WAIVER OR CONSENT SHALL BE EFFECTIVE ONLY
IN  THE  SPECIFIC  INSTANCE  AND  FOR  THE  SPECIFIC  PURPOSE  FOR  WHICH GIVEN.

          This  agreement  shall be governed by and construed in accordance with
the  laws  of the Commonwealth of Massachusetts.  Please note that to the extent
any of the terms or provisions of this Line of Credit Letter conflict with those
contained  in the Note or any of the Loan Documents, the terms and provisions of
the  Note  and  of  such  other  Loan  Documents  shall  govern.

          This  agreement  and  the  other Loan Documents to which Borrower is a
party  embody  the  entire  agreement  between  Borrower  and us relating to the
subject  matter  thereof and supersede all prior agreements, representations and
understandings,  if  any,  relating  to  the  subject  matter  thereof.

          All  notices,  requests, consents or other communications provided for
in  or to be given under this agreement shall be in writing, may be delivered in
person,  by  facsimile  transmission  (fax),  by  overnight  air  courier  or by
certified or registered mail, and shall be deemed to have been duly given and to
have  become  effective  (a)  upon receipt if delivered in person or by fax (and
followed by the same or next business day of mailing of such faxed notice by one
of  the other methods of delivery permitted hereunder), (b) one day after having
been  delivered to an overnight air courier, or (c) three days after having been
deposited  in  the  mails  as  certified  or  registered mail, all fees prepaid,
directed  to the parties at the following addresses (or at such other address as
shall  be  given  in  writing  by  a  party  hereto):

               If  intended  for  us:

               Cardiotech  International,  Inc.
               78-E  Olympia  Avenue
               Woburn,  MA  01801
               Attention:   Michael  Szycher
               Tel:  (781)  933-4772
               Fax:  (781)  937-4218


                                        7
<PAGE>
               With  a  copy  to:

               Ellenoff  Grossman  Schole  &  Cyruli,  LLP
               370  Lexington  Avenue,  Suite  1900
               New  York,  New  York  10017
               Attention:  Barry  Grossman,  Esq.
               Tel:  (212)  370-1300
               Fax:  (212)  370-7889

               If  intended  for  Borrower:

               Implant  Sciences  Corporation
               107  Audubon  Road
               Wakefield,  Massachusetts  01880-1246
               Tel:  (781)  246-0700
               Fax:  (781)  246-3561

               With  a  copy  to:

               Law Office of Bruce A. Bierhans LLC
               294  Pleasant  Street
               Stoughton,  Mass.  02072
               Attention:  Bruce  A.  Bierhans,  Esq.
               Tel:  (781)  297-0005
               Fax:  (781)  297-7427

          WE  EACH  AGREE  THAT  ANY ACTION, SUIT OR PROCEEDING IN RESPECT OF OR
ARISING  OUT OF THIS AGREEMENT, THE NOTE OR ANY OTHER LOAN DOCUMENTS RELATING TO
THISCREDIT LINE, MAY BE INITIATED AND PROSECUTED IN THE STATE OR FEDERAL COURTS,
AS  THE  CASE MAY BE, LOCATED IN OR CLOSEST IN GEOGRAPHIC PROXIMITY TO MIDDLESEX
COUNTY,  MASSACHUSETTS.

          EACH  OF  US  HEREBY  WAIVE TRIAL BY JURY IN ANY ACTION, PROCEEDING OR
COUNTERCLAIM  BROUGHT BY OR AGAINST IT ON ANY MATTERS WHATSOEVER, IN CONTRACT OR
IN TORT, ARISING OUT OF OR IN ANY WAY CONNECTED WITH THIS AGREEMENT, THE NOTE OR
ANY OTHER LOAN DOCUMENTS RELATING TO THISCREDIT LINE.  YOU ALSO HEREBY WAIVE THE
RIGHT  TO  INTERPOSE  ANY  DEFENSE  BASED UPON ANY CLAIM OF LACHES OR SET-OFF OR
COUNTERCLAIM  OF  ANY  NATURE  OR  DESCRIPTION, ANY OBJECTION BASED ON FORUM NON
CONVENIENS  OR  VENUE,  AND  ANY  CLAIM  FOR  CONSEQUENTIAL, PUNITIVE OR SPECIAL
DAMAGES.


                                        8
<PAGE>
          If this agreement is acceptable to you, please sign and return to us a
copy  of  this  letter no later than October 15, 2001, at which time this Credit
Line Letter shall be null and void and of no force or effect if it is not signed
by  you  and  returned  to  us.




                              Very  truly  yours,

                              Cardiotech  International,  Inc.


                              By:  /s/  Michael  Szycher
                                 -----------------------
                                 Michael  Szycher
                                 President


Agreed  to  and  accepted:

Implant  Sciences  Corporation


By:  /s/  Anthony  J.  Armini
   --------------------------
     Anthony  J.  Armini
     President


                                        9
<PAGE>