FORM 4

 o Check this box if no longer subject to Section 16.  Form 4 or Form 5 obligations may continue.
See Instruction 1(b).

(Print or Type Responses)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section
17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the
Investment Company Act of 1940

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 1. Name and Address of Reporting Person *

(Last)            (First)              (Middle)

(Street)

(City)       (State)          (Zip)

 2. Issuer Name and Ticker
    or Trading Symbol

MacroPore Biosurgery, Inc.

 3. I.R.S. Identification
    Number of Reporting
    Person, if an entity
    (voluntary)

 4. Statement for
 Month/Day/Year

April 30, 2003

 5. If Amendment, Date of
   Original (Month/Day/Year)

 6. Relationship of Reporting Person(s) to Issuer

(Check all applicable)

      Director

   X   Officer (give title below)

      10% Owner

      Other (specify below)

Senior Vice President of Marketing & Development for Biomaterials

 7. Individual or Joint/Group
     Filing (Check Applicable Line)

  X  Form filed by One Reporting Person

      Form filed by More than One Reporting Person

1. Title of Security
(Instr. 3)

2. Transaction Date (Month/Day/
Year)

2A. Deemed Execution Date, if any (Month/Day/
Year)

3. Transaction Code
(Instr. 8)

4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)

5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)

6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)

7. Nature of Indirect Beneficial Ownership
(Instr. 4)

Code

V

Amount

(A) or (D)

Price

Table II — Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date
(Month/Day/
Year)

3A. Deemed Execution Date, if any (Month/Day/
Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)

6. Date Exercisable and Expiration Date
(Month/Day/Year)

7. Title and Amount of Underlying Securities
(Instr. 3 and 4)

8. Price of Derivative Security
(Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)

10. Ownership Form of Derivative Securities: Direct (D) or Indirect (I)
(Instr. 4)

11. Nature of Indirect Beneficial Ownership
(Instr. 4)

Code

V

(A)

(D)

Date
Exercisable

Expiration
Date

Title

Amount or Number of Shares

Employee Stock Option (Rights to Buy)

4.35

4-30-03

D

35,000

2-28-03(1)

1-28-13

Common Stock

35,000

N/A(2)

225,000

D

Explanation of Responses:

(1) Employee Stock Options vest 1/48th each month from the date of grant.

(2)  Options cancelled voluntarily for consideration of agreement to receive the same number of options at a future date if still employed with the Company.

** Signature of Reporting Person

Date