EXHIBIT
      4.3




**FIRST
      AMENDMENT TO LEASE**




This
      FIRST AMENDMENT TO LEASE (this "Amendment") is entered into as of the
      1 st day of
      June, 2007 by and between **SFERS
      REAL ESTATE K LIMITED PARTNERSHIP** ,
      an Ohio
      limited partnership, by RREEF MANAGEMENT COMPANY, a Delaware corporation
      ("Landlord"), and **BIO-BRIDGE
      SCIENCE INC.,** a
      Delaware corporation ("Tenant"), for certain premises located in the building
      commonly known as 1211 West 22 nd Street,
      Oak Brook, Illinois (the "Building").





**RECITALS**





WHEREAS,
      Landlord and Tenant are parties to that certain Lease with a Lease Reference
      Date of July 20, 2004 (the "Lease") for approximately 1,253 rentable square
      feet
      on the sixth floor of the Building commonly known as Suite #615 (the
      "Premises"); and





WHEREAS,
      the term of the Lease is scheduled to expire on August 31, 2007.





WHEREAS,
      Landlord and Tenant desire to extend the term of the Lease as set forth herein.





NOW,
      THEREFORE, in consideration of the foregoing recitals and for other good and
      valuable consideration, the receipt and sufficiency of which are hereby
      acknowledged, Landlord and Tenant hereby agree to amend the Lease as
      follows:





**AGREEMENT**




Capitalized
      Terms **.** **All
      capitalized terms used herein shall have the same meanings ascribed to them
      in
      the Lease, unless otherwise defined in this Amendment.**




Term **.
      The Term of the Lease is hereby extended by three (3) years commencing September
      1, 2007 and continuing until August 31, 2010 (the "Renewal Term") on the terms
      and conditions herein contained and otherwise contained in the
      Lease.**




Rent
      Schedule. **During the Renewal Term, Tenant shall pay the Annual Rent and the Monthly
      Installments thereof as follows:**




**Period**
            **Annual
                Rent**
              **per
                square foot**
            **Annual
                Rent**
            **Monthly
                Installment**
              **of
                Rent**9/1/07-9/30/07
            $0.00
            $0.00
            $0.0010/1/07-8/31/08
            $21.75
            $27,252.75
            $2,271.079/1/08-8/31/09
            $22.25
            $27,879.25
            $2,323.279/1/09-8/31/10
            $22.75
            $28,505.75
            $2,375.45




4.  **Base
      Year** .
      The
      Base Year (Expenses) shall be 2007 and the Base Year (Taxes) shall be 2007
      (payable in 2008).





5.  **Condition
      of Premises** .
      Landlord hereby agrees to shampoo the carpet in the Premises and replace all
      light bulbs that are not operational. Except as set forth herein, Tenant agrees
      that Landlord shall have no obligation to perform any construction or make
      any
      improvements or alterations in connection with this Amendment, and Tenant
      acknowledges and agrees that all construction obligations of Landlord, or
      agreements to provide allowances therefor, under the Lease have been performed
      in full and accepted.




6.  **Brokers** .
      Tenant
      represents and warrants to Landlord that no real estate broker, agent,
      commissioned salesperson or other person has represented Tenant in the
      negotiations of this Amendment. Tenant agrees to indemnify and hold Landlord
      harmless from and against any claim for any such commissions, fees or other
      form
      of compensation by any such third party claiming through the Tenant, including
      without limitation, any brokers specifically named in the Lease, including
      without limitation, any and all claims, causes of action, damages, costs and
      expenses, including attorneys' fees, associated therewith.








**7.**  Incorporation **.
      Except as otherwise amended herein, all other terms and conditions of the Lease
      shall remain in full force and effect and Tenant hereby ratifies and confirms
      its obligations thereunder. Tenant acknowledges that as of the date of this
      Amendment, Tenant (i) is not in default under the terms of the Lease; (ii)
      has
      no defense, set off or counterclaim to the enforcement by Landlord of the terms
      of the Lease; and (iii) is not aware of any action or inaction by Landlord
      that
      would constitute an event of default under the Lease.**




**8.**  Tenant's
      Authority **.**




**If
      Tenant signs as a corporation, partnership, trust or other legal entity each
      of
      the persons executing this Amendment on behalf of Tenant represents and warrants
      that Tenant has been and is qualified to do business in the state in which
      the
      Building is located, that the entity has full right and authority to enter
      into
      this Amendment, and that all persons signing on behalf of the entity were
      authorized to do so by appropriate actions. Tenant agrees to deliver to
      Landlord, simultaneously with the delivery of this Amendment, a corporate
      resolution, proof of due authorization by partners, opinion of counsel or other
      appropriate documentation reasonably acceptable to Landlord evidencing the
      due
      authorization of Tenant to enter into this Amendment.**




Tenant
      hereby represents and warrants that neither Tenant, nor any persons or entities
      holding any legal or beneficial interest whatsoever in Tenant, are (i) the
      target of any sanctions program that is established by Executive Order of the
      President or published by the Office of Foreign Assets Control, U.S. Department
      of the Treasury ("OFAC"); (ii) designated by the President or OFAC pursuant
      to
      the Trading with the Enemy Act, 50 U.S.C. App. § 5, the International Emergency
      Economic Powers Act, 50 U.S.C. §§ 1701-06, the Patriot Act, Public Law 107-56,
      Executive Order 13224 (September 23, 2001) or any Executive Order of the
      President issued pursuant to such statutes; or (iii) named on the following
      list
      that is published by OFAC: "List of Specially Designated Nationals and Blocked
      Persons." If the foregoing representation is untrue at any time during the
      Term,
      an Event of Default will be deemed to have occurred, without the necessity
      of
      notice to Tenant.





**9.**  Limitation
      of Landlord's Liability **.** **Redress
      for any claim against Landlord under the Lease or Amendment shall be limited
      to
      and enforceable only against and to the extent of Landlord's interest in the
      Building. The obligations of Landlord under the Lease as amended hereby are
      not
      intended to be and shall not be personally binding on, nor shall any resort
      be
      had to the private properties of, any of its or its investment manager's
      trustees, directors, officers, partners, beneficiaries, members, stockholders,
      employees, or agents, and in no case shall Landlord be liable to Tenant
      hereunder for any lost profits, damage to business, or any form of special,
      indirect or consequential damages.**




IN
      WITNESS WHEREOF, Landlord and Tenant have executed this Amendment as of the
      day
      and year first written above.




LANDLORD:
            
            TENANT:SFERS
                REAL ESTATE K LIMITED
              PARTNERSHIP,
                an Ohio limited partnership
            
            BIO-BRIDGE
              SCIENCE INC., a Delaware corporationBy: RREEF
              Management Company, a Delaware corporation
            
            By:
            Dr.
              Liang Qiao /s/Name:
            Dr.
              Liang
              QiaoBy:
            Mark
              Sabatino/s/
            
            Title:
            Chief
              Executive
              OfficerMark
                Sabatino
              Vice
                President, District Manager
            
            Dated:
                June 1,
                2007Dated:
              June 1,
              2007