Protein Polymer Issued Two More Key U.S. Patents

    SAN DIEGO, Oct. 15, 1996 -- Protein Polymer Technologies, Inc.(Nasdaq: PPTI), today announced that the U.S. Patent and Trademark Office has issued to the Company two additional pioneering patents encompassing its protein polymer biomaterials technology.  PPTI currently has four issued U.S. patents, two about to be issued, and thirteen additional patent applications pending.  Corresponding patent applications have been filed in major international markets.
    Patent No. 5,496,712 "High Molecular Weight Collagen-Like Protein Polymers" describes the recombinant production of synthetic high molecular weight collagen-like polymers that incorporate into the molecular structure new synthetic properties while retaining selected natural "collagen" properties.  In nature, collagen makes up more than 80 percent of the body's connective tissue.  Collagen extracted from animals (primarily from cow hides) has been widely used for such medical purposes as an hemostatic agent and for a variety of tissue augmentation procedures.  Medical researchers have long sought an effective substitute for animal-derived collagen due to mechanical limitations and its potential to cause immunological reactions.  PPTI's collagen-like materials have the potential to avoid immunological problems and to provide significantly better mechanical and formulation properties.
    Patent No. 5,514,581 "Functional Recombinantly Prepared Synthetic Protein Polymers" describes structural protein polymer backbones containing multiple functional peptide sequences, such as cell growth promoters and attachment sites for mammalian cells.  PPTI's ProNectin(R)F -- a protein polymer with a crystalline, silk-like backbone containing multiple cell attachment sites from human fibronectin -- is incorporated in this patent as an example and a new composition of matter.  It is sold commercially for biomedical research requiring the growth of mammalian cells outside the body.
    "These patents demonstrate the exceptional depth and breadth of our protein polymer technology and reinforce our pioneering position in the field of biomaterials," said J. Thomas Parmeter, President and Chief Executive Officer of Protein Polymer Technologies, Inc.  "We continue to protect our technology through a patent strategy that involves a layered approach covering, respectively, protein and DNA compositions, polymer design and recombinant DNA methodology, and applications and products.  We believe that this approach has resulted in an exceptionally strong proprietary position that will protect the Company's commercial interests in both the short and long term."
    Protein Polymer Technologies, Inc. is a development stage biomaterials company focused on tissue repair and drug delivery.  PPTI's genetically engineered, protein-based biomaterials can be designed specifically for use as biocompatible implants directing the activities of mammalian cells.  Products being developed include tissue adhesives and sealants, wound healing matrices, surgical adhesion barriers, and drug delivery devices.  PPTI also markets a line of protein polymer-activated cell culture products under the trade names of ProNectin(R) and SmartPlastic(R).

For more information on these and other issued patents, visit PPTI's online Patents page.