Restated Bylaws

Exhibit 4.2 ADVANCED TISSUE SCIENCES, INC. BY-LAWS As Adopted by the Board of Directors on July 17, 1987 and Amended through May 29, 2002

RESTATED BY-LAWS OF ADVANCED TISSUE SCIENCES, INC. (a Delaware Corporation) ARTICLE I OFFICES The Corporation shall maintain a registered office in the State of Delaware as required by law. The Corporation may also have offices at other places, within and without the State of Delaware. ARTICLE II STOCKHOLDERS SECTION 1. Annual meetings of stockholders for the election of directors and the transactions of such business as may properly come before the meeting shall be held once in each year at such times and such places, within or without the State of Delaware, as may be fixed from time to time by the Board of Directors. SECTION 2. Except as otherwise required by statute or the Corporation's Certificate of Incorporation, special meetings of stockholders may be called by the Board of Directors, the Chairman of the Board or stockholders which together hold at least 10% of the aggregate voting power of the stock issued by the Corporation that would be entitled to vote at the meeting. Special meetings of stockholders shall be held on such dates and at such times and such places, within or without the State of Delaware, as shall be stated in the notices of such meetings. Notice of any special meeting shall state the purpose or purposes for which the meeting is to be held and no other business shall be transacted except as stated in such notice. SECTION 3. Written notice of all meetings of the stockholders shall be mailed to or delivered to each stockholder entitled to vote thereat at least ten, but not more than fifty, days prior to the meeting. Notice of any meeting shall state in general terms the purposes for which the meeting is to be held and no other business shall be transacted except as stated in such notice. SECTION 4. The holders of a majority of the issued and outstanding shares of the capital stock of the Corporation entitled to vote thereat, present in person or represented by proxy, shall constitute a quorum for the transaction of business at all meetings of stockholders. SECTION 5. Except as otherwise required by statute, the Corporation's Certificate of Incorporation or these By-Laws, all matters coming before any meeting of stockholders shall be decided by the vote of the holders of a majority of the shares of capital stock of the Corporation present in person or represented by proxy at such meeting and voting thereon, a quorum being present. SECTION 6. The Board of Directors, or, if the Board shall not have made the appointment, the chairman presiding at any meeting of stockholders, shall have power to appoint two or more persons to act as inspectors, to receive, canvass and report the votes cast by the stockholders at such meeting. SECTION 7. The Chairman of the Board, or in his absence, the President, shall preside at all meetings of stockholders; and in their absence, the Board of Directors may appoint a person to act as chairman of the meeting.

2 SECTION 8. The Secretary or an Assistant Secretary shall act as secretary at all meetings of stockholders; and in their absence, the chairman of the meeting shall appoint a person to act as secretary of the meeting. ARTICLE III BOARD OF DIRECTORS SECTION 1. The business and affairs of the Corporation shall be managed by or under the direction of the Board of Directors. The Board of Directors shall consist of three or more directors, as may be fixed and from time to time increased or decreased by action of the Board of Directors or by the stockholders, but no decrease shall shorten the term of any incumbent director. SECTION 2. Any vacancies in the Board of Directors resulting from death, resignation, increase in the number of directors, or from any other reason whatsoever, may be filled by a vote of a majority of the directors then in office, although less than a quorum, or by vote of the stockholders. A director elected by the directors or stockholders to fill a vacancy shall hold office for the unexpired term of his predecessor. SECTION 3. Regular meetings of the Board of Directors shall be held on such dates and at such times and such places, within or without the State of Delaware, as shall be fixed from time to time by the Board. SECTION 4. Special meetings of the Board of Directors may be called by the Chairman of the Board and shall be called by the Chairman of the Board or the Secretary upon a request in writing by any two directors. Notice shall be given of the date, time and place of each special meeting by mailing the same at least three days before the meeting or by telephoning, telegraphing or delivering personally the same before the meeting to each director. Except as otherwise specified in the notice thereof, or as required by statute, the Certificate of Incorporation or these By-Laws, any and all business may be transacted at any special meeting of the Board of Directors. SECTION 5. The Chairman of the Board shall president all meetings of the Board of Directors; and in his absence, the President shall preside. A majority of the whole Board of Directors shall constitute a quorum for the transaction of business, but less than a quorum of the Board may adjourn any meeting from time to time until a quorum shall be present, whereupon the meeting may be held, as adjourned, without further notice. Except as otherwise required by statute, the Certificate of Incorporation or these By-Laws, all matters coming before any meeting of the Board of Directors shall be decided by the vote of a majority of the directors present at the meeting, a quorum being present. SECTION 6. Any action required or permitted to be taken at any meeting of the Board of Directors, or of any committee thereof, may be taken without a meeting if all members of the Board or committee, as the case may be, consent thereto in writing. SECTION 7. Members of the Board of Directors, or any committee designated by such Board, may participate in a meeting of such Board or committee, as the case may be, by means of conference telephone or similar communications equipment by means of which all persons participating in the meeting can hear each other, and participation in a meeting by such means shall constitute presence in person at such meeting.

3 ARTICLE IV COMMITTEES SECTION 1. The Corporation may have an Audit Committee, which shall have such powers of the Board of Directors, not prohibited by statute, as the Board shall from time to time authorize. The Audit Committee shall consist of two or more directors. SECTION 2. The Board of Directors may, by resolution passed by a majority of the whole Board, designate from among its own members such other committees, including, without limitation, an Executive committee and/or a Compensation Committee, as the Board may determine. Each such committee shall have such powers of the Board of Directors, not prohibited by statute, as the Board shall from time to time authorize. SECTION 3. A majority of the whole committee shall constitute a quorum for the transaction of business. Each committee shall keep regular minutes of its meetings and shall report the same to the Board of Directors when requested. The Board of Directors may discharge any committee or any member thereof either with or without cause at any time. SECTION 4. In the case of the absence or disqualification of a member of a committee, the member or members thereof present at any meeting and not disqualified from voting, whether or not constituting a quorum, may unanimously appoint another member of the Board of Directors to act at the meeting in place of such absent or disqualified member. ARTICLE V COMPENSATION OF DIRECTORS SECTION 1. The directors may be paid their expenses, if any, of attendance at each meeting of the Board of Directors and may be paid a fixed sum for attendance at each meeting of the board of directors or a stated salary as director. No such payment shall preclude any director from serving the corporation in any other capacity and receiving compensation therefor. Members of special or standing committees may be allowed like compensation for attending committee meetings. ARTICLE VI OFFICERS SECTION 1. The Board of Directors shall elect the following officers: Chairman of the Board of Directors, President, Treasurer and Secretar ...