<PAGE>   1
                                                                    EXHIBIT 3.11

                      RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                          NORTHFIELD LABORATORIES INC.


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

                    Pursuant to Sections 242 and 245 of the General
                    Corporation Law of the State of Delaware

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


         Northfield Laboratories Inc., a corporation organized and existing
under the laws of the State of Delaware (the "Corporation"), hereby certifies as
follows:

         The original Certificate of Incorporation of the Corporation was filed
on June 19, 1985.

         A Restated Certificate of Incorporation of the Corporation was filed on
May 5, 1994.

         This Restated Certificate of Incorporation amends and restates the
Certificate of Incorporation of the Corporation as heretofore in effect. This
Restated Certificate of Incorporation has been proposed by the Board of
Directors and adopted by the stockholders of the Corporation in the manner and
by the vote prescribed by Sections 242 and 245 of the General Corporation Law of
the State of Delaware, and is as follows:

         1.  Corporate Name. The name of the Corporation is Northfield
Laboratories Inc.

         2. Registered Office and Agent. The address, including street, number,
city and county, of the registered office of the Corporation in the State of
Delaware is Corporation Trust Center, 1209 Orange Street, Wilmington, New Castle
County, Delaware


<PAGE>   2
19801. The name of the registered agent of the Corporation in the State of
Delaware at such address is The Corporation Trust Company.

         3.  Purpose. The purpose of the Corporation is to engage in any lawful
act or activity for which corporations may be organized under the General
Corporation Law of the State of Delaware.

         4.  Authorized Capital Stock. The total number of shares of stock which
the Corporation shall have authority to issue is 35,000,000 shares, consisting
of 30,000,000 shares of Common Stock, par value $.01 per share (the "Common
Stock"), and 5,000,000 shares of Preferred Stock, par value $.01 per share (the
"Preferred Stock"). The Preferred Stock may be issued from time to time in one
or more series. The Board of Directors of the Corporation (the "Board of
Directors") is expressly authorized to provide for the issuance of the Preferred
Stock in one or more series, and to fix the number of shares and to determine or
alter for each such series, such voting powers, full or limited, or no voting
powers, and such designations, preferences, and relative, participating,
optional or other rights, and such qualifications, limitations or restrictions
thereof, as shall be stated and expressed in the resolution or resolutions
adopted by the Board of Directors providing for the issuance of such shares and
as may be permitted by the General Corporation Law of the State of Delaware. The
Board of Directors is also expressly authorized to increase or decrease (but not
below the number of shares of such series outstanding) the number of shares of
any series subsequent to the issuance of shares of that series. In case the
number of shares of any such series shall so decrease, the shares constituting
such decrease shall resume the status that they had prior to the adoption of the
resolution originally fixing the number of shares of such series.

         5.  Action by Stockholders. Special meetings of stockholders of the
Corporation may be called only by the Board of Directors pursuant to a
resolution approved by a majority of the entire Board of Directors. Any action
required or permitted to be taken by the stockholders of the Corporation must be
effected at a duly called annual or special meeting of such holders and may not
be effected by any consent in writing by such stockholders. At any annual or
special meeting of the stockholders of the Corporation, only such business shall
be conducted as shall have been brought before such meeting in the manner
provided in the Bylaws of the Corporation.

         6.  Board of Directors. The business and affairs of the Corporation
shall be managed and controlled by a Board of Directors consisting of not less
than three nor more than eleven persons. The exact number of directors within
the minimum and maximum numbers specified in the preceding sentence shall be
fixed from time to time by the Board of Directors pursuant to a resolution
adopted by a majority of the entire Board of Directors. Subject to the rights of
the holders of any series of Preferred Stock outstanding, newly created
directorships resulting from any increase in the authorized number of directors
or any vacancies in the Board of Directors resulting from death, resignation,
retirement, disqualification, removal from office or other cause shall be filed
by a majority of the directors then in office, and the directors so chosen shall
hold office for a term expiring at the next annual meeting of stockholders of
the Corporation. No decrease in the



<PAGE>   3


number of directors constituting the Board of Directors shall shorten the term
of any incumbent director. In discharging the duties of their respective
positions, the Board of Directors, committees of the Board of Directors,
individual directors and officers may, in considering the best long-term and
short-term interests of the Corporation, consider the effects of any action
(including, without limitation, action which may involve or relate to a change
or potential change in control of the Corporation) upon employees, suppliers and
customers of the Corporation, communities in which offices or other
establishments of the Corporation are located, and all other pertinent factors.

         7.  Fair Price Provision.

             (a)  The affirmative vote of the holders of at least 80 percent of
      the outstanding shares of Voting Stock (as hereinafter defined) held by
      stockholders other than an Interested Stockholder (as hereinafter defined)
      shall be required for the approval or authorization of any Business
      Combination (as hereinafter defined) of the Corporation with any
      Interested Stockholder; provided that the 80 percent voting requirement
      shall not be applicable if:

                  (i)   the Continuing Directors (as hereinafter defined) of the
         Corporation by at least a two-thirds vote (A) have expressly approved
         in advance the acquisition of the outstanding shares of Voting Stock
         that caused such Interested Stockholder to become an Interested
         Stockholder or (B) have expressly approved such Business Combination,
         either in advance of or subsequent to such Interested Stockholder
         having become an Interested Stockholder; or

                  (ii)  the cash or fair market value (as determined by at least
         two-thirds of the Continuing Directors) of the property, securities or
         other consideration to be received per share by holders of Voting Stock
         of the Corporation in the Business Combination is not less than the
         Highest Per Share Price or the Highest Equivalent Price (as such terms
         are hereinafter defined) paid by the Interested Stockholder in
         acquiring any Voting Stock of the Corporation.

             (b)  For purposes of this Section 7:

                  (i)   the term "Business Combination" shall mean (A) any
         merger or consolidation of the Corporation or a subsidiary of the
         Corporation with or into an Interested Stockholder, (B) any sale,
         lease, exchange, transfer, license or other disposition, including,
         without limitation, a mortgage or any other security device, of all or
         any Substantial Part (as hereinafter defined) of the assets either of
         the Corporation (including, without limitation, any voting securities
         of a subsidiary) or of a subsidiary




<PAGE>   4


         of the Corporation to an Interested Stockholder, (C) any merger or
         consolidation of an Interested Stockholder with or into the Corporation
         or a subsidiary of the Corporation, (D) any sale, lease, exchange,
         transfer or other disposition, including, without limitation, a
         mortgage or other security device, of all or any Substantial Part of
         the assets of an Interested Stockholder to the Corporation or a
         subsidiary of the Corporation, (E) the issuance of any securities of
         the Corporation or a subsidiary of the Corporation to an Interested
         Stockholder, (F) any recapitalization that would have the effect of
         increasing the voting power of an Interested Stockholder and (G) any
         agreement, contract or other arrangement providing for any of the
         transactions described in this definition of Business Combination;

                  (ii) the term "Interested Stockholder" shall mean and include
         any individual, corporation, partnership or other person or entity
         which, together with its Affiliates and Associates (as defined in Rule
         12b-2 of the General Rules and Regulations under the Securities
         Exchange Act of 1934 as in effect at the date of the adoption of this
         Restated Certificate of Incorporation by the stockholders of the
         Corporation (collectively, and as so in effect, the "Exchange Act"))
         Beneficially Owns (as defined in Rule 13d-3 of the Exchange Act) in the
         aggregate 15 percent or more of the outstanding Voting Stock of the
         Corporation, and any Affiliate or Associate of any such individual,
         corporation, partnership or other person or entity;

                  (iii) any share of Voting Stock of the Corporation that any
         Interested Stockholder has the right to acquire at any time
         (notwithstanding that Rule 13d-3 deems such shares to be beneficially
         owned only if such right may be exercised within 60 days) pursuant to
         any agreement, or upon exercise of conversion rights, warrants or
         options or otherwise, shall be deemed to be Beneficially Owned by the
         Interested Stockholder and to be outstanding for purposes hereof;

                  (iv) the term "Substantial Part" shall mean more than 15
         percent of the fair market value as determined by two-thirds of the
         Continuing Directors of the total consolidated assets of the
         Corporation and its subsidiaries taken as a whole as of the end of its
         most recent fiscal year ended prior to the time the determination is
         being made;

                  (v) for the purposes of subparagraph (ii) of Section 7(a), the
         term "other consideration to be received" shall include, without
         limitation, Common Stock or other capital stock of the Corporation
         retained by its existing stockholders other than Interested
         Stockholders or other parties to such Business Combination in the event
         of a Business Combination in which the Corporation is the surviving
         corporation;



<PAGE>   5


                  (vi) the term "Voting Stock" shall mean all of the outstanding
         shares of Common Stock and the outstanding shares of Preferred Stock
         entitled to vote on each matter on which the holders of record of
         Common Stock shall be entitled to vote, and each reference to a
         proportion of shares of Voting Stock shall refer to such proportion of
         the votes entitled to be cast by such shares;

                  (vii) the term "Continuing Director" shall mean a Director who
         (A) was a member of the Board of Directors of the Corporation
         immediately prior to the time that the Interested Stockholder involved
         in a Business Combination became an Interested Stockholder or (B) is
         not an Interested Stockholder or an Affiliate or an Associate of an
         Interested Stockholder and whose nomination or election to the Board of
         Directors is recommended or approved by a majority of the Directors
         deemed to be Continuing Directors pursuant to clause (A) hereof;

                  (viii) an Interested Stockholder shall be deemed to have
         acquired a share of the Voting Stock of the Corporation at the time
         when such Interested Stockholder became the Beneficial Owner thereof.
         With respect to the shares owned by Affiliates, Associates or other
         persons whose ownership is attributed to an Interested Stockholder
         under the foregoing definition of Interested Stockholder, if the price
         paid by such Interested Stockholder for such shares is not determinable
         by two-thirds of the Continuing Directors, the price so paid shall be
         deemed to be the higher of (A) the price paid upon the acquisition
         thereof by the Affiliate, Associate or other person or (B) the market
         price of the shares in question at the time when the Interested
         Stockholder became the Beneficial Owner thereof; and

                  (ix) the terms "Highest Per Share Price" and "Highest
         Equivalent Price" as used in this Section 7 shall mean the following:
         If there is only one class of capital stock of the Corporation issued
         and outstanding, the Highest Per Share Price shall mean the highest
         price that can be determined to have been paid at any time by the
         Interested Stockholder for any share or shares of that class of capital
         stock. If there is more than one class of capital stock of the
         Corporation issued and outstanding, the Highest Equivalent Price shall
         mean with respect to each class and series of capital stock of the
         Corporation, the amount determined by two-thirds of the Continuing
         Directors, on whatever basis they believe is appropriate, to be the
         highest per share price equivalent of the highest price that can be
         determined to have been paid at any time by the Interested Stockholder
         for any share or shares of any class or series of capital stock of the
         Corporation. In determining the Highest Per Share Price and Highest
         Equivalent Price, all



<PAGE>   6


         purchases by the Interested Stockholder shall be taken into account
         regardless of whether the shares were purchased before or after the
         Interested Stockholder became an Interested Stockholder. The Highest
         Per Share Price and the Highest Equivalent Price shall include any
         brokerage commissions, transfer taxes and soliciting dealers' fees paid
         by the Interested Stockholder with respect to the shares of capital
         stock of the Corporation acquired by the Interested Stockholder. In the
         case of any Business Combination with an Interested Stockholder, the
         Continuing Directors shall determine the Highest Equivalent Price for
         each class and series of the capital stock of the Corporation.

         8.  Indemnification. The Corporation shall indemnify any person who was
or is a party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of the Corporation) by
reason of the fact that he is or was a director, officer, employee or agent of
the Corporation, or is or was serving at the request of the Corporation as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise, against expenses (including, without
limitation, attorneys' fees and expenses), judgments, fines and amounts paid in
settlement actually and reasonably incurred by him in connection with such
action, suit or proceeding if he acted in good faith and in a manner he
reasonably believed to be in or not opposed to the best interests of the
Corporation, and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his conduct was unlawful. The termination of any
action, suit or proceeding by judgment, order, settlement, conviction, or upon a
plea of nolo contendere or its equivalent, shall not, of itself, create a
presumption that the person did not act in good faith and in a manner which he
reasonably believed to be in or not opposed to the best interests of the
Corporation, and, with respect to any criminal action or proceeding, had
reasonable cause to believe that his conduct was unlawful.

         The Corporation shall indemnify any person who was or is a party or is
threatened to be made a party to any threatened, pending or completed action or
suit by or in the right of the Corporation to procure a judgment in its favor by
reason of the fact that he is or was a director, officer, employee or agent of
the Corporation, or is or was serving at the request of the Corporation as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise against expenses (including, without
limitation, attorneys' fees and expenses) actually and reasonably incurred by
him in connection with the defense or settlement of such action or suit if he
acted in good faith and in a manner he reasonably believed to be in or not
opposed to the best interests of the Corporation and except that no
indemnification shall be made in respect of any claim, issue or matter as to
which such person shall have been adjudged to be liable to the Corporation
unless and only to the extent that the Court of Chancery of the State of
Delaware or the court in which such action or suit was brought shall determine
upon application that, despite the adjudication of liability but in view of all
the circumstances of the case, such person is



<PAGE>   7



fairly and reasonably entitled to indemnity for such expenses which the Court of
Chancery or such other court shall deem proper.

         Any indemnification under the previous two paragraphs of this Section 8
(unless ordered by a court) shall be made by the Corporation only as authorized
in the specific case upon a determination that indemnification of the director,
officer, employee or agent is proper in the circumstances because he has met the
applicable standard of conduct set forth in such paragraphs. Such determination
shall be made (a) by the Board of Directors by a majority vote of a quorum
consisting of directors who were not parties to such action, suit or proceeding,
(b) if such quorum is not obtainable, or, even if obtainable, if a quorum of
disinterested directors so directs, by independent legal counsel in a written
opinion or (c) by the stockholders of the Corporation.

         Expenses (including attorneys' fees and expenses) incurred by a
director, officer, employee or agent in defending any civil, criminal,
administrative or investigative action, suit or proceeding shall be paid by the
Corporation in advance of the final disposition of such action, suit or
proceeding upon receipt of an undertaking by or on behalf of such person to
repay such amount if it shall ultimately be determined that he is not entitled
to be indemnified by the Corporation as authorized in this Section 8.

         The indemnification and advancement of expenses provided by, or granted
pursuant to, this Section 8 shall not be deemed exclusive of any other rights to
which those seeking indemnification or advancement of expenses may be entitled
under any Bylaw, agreement, vote of stockholders or disinterested directors or
otherwise, both as to action in his official capacity as to action in another
capacity while holding such office.

         The Corporation shall have power to purchase and maintain insurance on
behalf of any person who is or was a director, officer, employee or agent of the
Corporation, or is or was serving at the request of the Corporation as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise against any liability asserted against him
and incurred by him in any such capacity, or arising out of his status as such,
whether or not the Corporation would have the power to indemnify him against
such liability under the provisions of this Section 8.

         For purposes of this Section 8 references to "the Corporation" shall
include, in addition to the resulting corporation, any constituent corporation
(including any constituent of a constituent) absorbed in a consolidation or
merger which, if its separate existence had continued, would have had power and
authority to indemnify its directors, officers, employees or agents, so that any
person who is or was a director, officer, employee or agent of such constituent
corporation, or is or was serving as the request of such constituent corporation
as a director, officer, employee or agent of another corporation, partnership,
joint venture, trust or other enterprise, shall stand in the same position under
the provisions of this Section 8 with respect to the resulting or surviving
corporation as he




<PAGE>   8


would have with respect to such constituent corporation if its separate
existence had continued.

         For purposes of this Section 8, references to "other enterprises" shall
include employee benefit plans; references to "fines" shall include any excise
taxes assessed on a person with respect to an employee benefit plan; and
references to "serving at the request of the Corporation" shall include any
service as a director, officer, employee or agent of the Corporation which
imposes duties on, or involves services by, such director, officer, employee or
agent with respect to an employee benefit plan, its participants or
beneficiaries; and a person who acted in good faith and in a manner he
reasonably believed to be in the interest of the participants and beneficiaries
of an employee benefit plan shall be deemed to have acted in a manner "not
opposed to the best interests of the Corporation" as referred to in this Section
8.

         The indemnification and advancement of expenses provided by, or granted
pursuant to, this Section 8 shall continue as to a person who has ceased to be a
director, officer, employee or agent and shall inure to the benefit of the
heirs, executors and administrators of such a person.

         9.  Liability of Directors. No director of the Corporation shall be
personally liable to the Corporation or its stockholders for monetary damages
for breach of fiduciary duty as a director, except for liability (a) for any
breach of the director's duty of loyalty to the Corporation or its stockholders,
(b) for acts or omissions not in good faith or which involve intentional
misconduct or a knowing violation of law, (c) under Section 174 of the General
Corporation Law of the State of Delaware, as the same exists or hereafter may be
amended, or (d) for any transaction from which the director derived an improper
personal benefit. Any repeal or modification of this Section 9 by the Board of
Directors or stockholders of the Corporation shall be prospective only, and
shall not adversely affect any limitation on the personal liability of a
director of the Corporation existing at the time of such repeal or modification.
Nothing herein shall limit or otherwise affect the obligation or right of the
Corporation to indemnify its directors pursuant to the provisions of this
Restated Certificate of Incorporation, the Bylaws of the Corporation or as may
be permitted by the General Corporation Law of the State of Delaware.

         10. Amendment. The provisions of this Restated Certificate of
Incorporation may not be amended, altered or repealed in any respect unless such
action is approved by the affirmative vote of the holders of at least 80 percent
of the outstanding shares of Voting Stock (as defined in Section 7) of the
Corporation at a meeting of the stockholders of the Corporation duly called for
the consideration of such amendment, alteration or repeal; provided that if
there is an Interested Stockholder (as defined in Section 7), such action must
also be approved by the affirmative vote of the holders of at least 80 percent
of the outstanding shares of Voting Stock held by stockholders other than the
Interested Stockholder.




<PAGE>   9



         11. Bylaws. In furtherance and not in limitation of the powers
conferred by statute, the Board of Directors is expressly authorized to (a)
make, alter or repeal the Bylaws of the Corporation, and (b) adopt from time to
time Bylaw provisions with respect to indemnification of directors, officers,
employees, agents and other persons as it shall deem expedient and in the best
interests of the Corporation and to the extent permitted by law.

         12. Voting by Ballot. Elections of directors need not be by written
ballot unless the Bylaws of the Corporation so provide.


                                    * * * * *


         IN WITNESS WHEREOF, the Corporation has caused this Certificate to be
executed by its Chief Executive Officer and attested by its Secretary as of this
November 3, 1999.

                                         NORTHFIELD LABORATORIES INC.


                                         /s/ Richard E. DeWoskin
                                         -------------------------------------
                                             Richard E. DeWoskin
                                             Chief Executive Officer


                                         ATTEST:

                                         /s/ Jack J. Kogut
                                         -------------------------------------
                                             Jack J. Kogut
                                             Secretary