Protein Polymer Technologies, Inc.

Erwin R Stedronsky

Joseph Cappello

David M Donofrio

David A Donofrio

Proteinaceous polymers having repetitive units from naturally occurring structural proteins are employed as backbones for functionalities for crosslinking to provide strongly adherent tissue adhesives and sealants. Particularly, block copolymers of elastin and fibroin are employed having lysine substitutions in spaced apart units, where the amino group can be crosslinked using difunctional crosslinking agents.

Adhesion and sealing of tissue with compositions containing polyfunctional crosslinking agents and protein polymers

The present invention concerns novel methods for enhancing the mechanical performance of tissue adhesives and sealants which comprises employing a primer molecule in association with a tissue adhesive or sealant, wherein the primer molecule serves to enhance the strength of the interface between the tissue and the adhesive matrix. The primer molecules described herein function to interact with a protein present in the tissue, thereby altering its characteristics to make it more amenable to bonding with the adhesive matrix. Primer molecules may be applied to the tissue independently from the tissue adhesive or sealant or may be mixed with the tissue adhesive or sealant prior to application to the tissue.

Methods of using primer molecules for enhancing the mechanical performance of tissue adhesives and sealants

Proteinaceous polymers having repetitive units from naturally occurring structural proteins are employed as backbones for functionalities for crosslinking to provide strongly adherent tissue adhesive compositions for bonding together separated tissue, and for sealing or filling tissue defects by injecting the compositions into the defects. Particularly, block copolymers having repeating units of elastin and fibroin are employed having lysine substitutions in spaced apart units, where the amino group can be crosslinked using difunctional crosslinking agents such as glutaraldehyde, activated diolefins, diisocyanates, acid anhydrides or diamines. The protein polymer contains at least 40 weight percent of repetitive units of 3 to 30 amino acids, preferably 3 to 15 amino acids, of at least one naturally occurring structural protein and at least two amino acids containing a functional group capable of reacting with the crosslinking agent. The protein polymer generally has a molecular weight of at least about 30 kD and not more than 250 kD. A preferred protein polymer contains at least 70 weight percent of repetitive units of Gly-Ala-Gly-Ala-Gly-Ser and Gly-Val-Gly-Val-Pro, where in at least two units an amino acid is substituted with one of lysine or arginine, and the protein polymer has a lysine and arginine equivalent weight in the range of 1 to 20 kD and contains at least two amino acids having a functional group capable of reacting with at least one of aldehyde, isocyanate, thioisocyanate and activated carboxy. The protein polymer is produced by recombinant DNA technology, and a kit may be formed containing the crosslinking agent and protein polymer.

Sealing or filling tissue defects using polyfunctional crosslinking agents and protein polymers

Method and compositions are provided which are useful for delivering a biologically active substance to a localized site in vivo and for altering the physical dimensions of a body tissue. These method and compositions employ protein polymers having varying ratios of elastin-like collagen-like, keratin-like repeating units and repeating units which promote protein crystallization such as silk-like repeating units. By varying the length of segments of the repeating units and/or the concentration of the protein polymers in the composition, the rate of delivery of a biologically active substance to a localized site can be greatly varied. Moreover, because the compositions are capable of acquiring a non-liquid form under normal physiological conditions, they find use as biocompatible tissue augmentation products.

Synthetic proteins for in vivo drug delivery and tissue augmentation

Proteinaceous polymers having repetitive units from naturally occurring structural proteins are employed as backbones for functionalities for crosslinking to provide strongly adherent tissue adhesives and sealants. Particularly, block copolymers having repeating units of elastin and fibroin are employed having lysine substitutions in spaced apart units, where the amino group can be crosslinked using difunctional crosslinking agents. The protein polymer contains at least 40 weight percent of repetitive units of 3 to 30 amino acids of at least one naturally occurring structural protein and at least two functional groups capable of reacting with a crosslinking agent to form a strongly adherent adhesive composition for bonding together separated tissue or for sealing tissue defects. A preferred adhesive composition contains glutaraldehyde or polymethylene diisocyanate and a protein block copolymer of at least 30 kD containing at least 70 weight percent of repetitive units of Gly-Ala-Gly-Ala-Gly-Ser and Gly-Val-Gly-Val-Pro, where in at least two units an amino acid is substituted with one of lysine or arginine, and the copolymer has a lysine and arginine equivalent weight in the range of 3 to 15 kD. The protein polymer is produced by recombinant DNA technology, and a kit may be formed containing the crosslinking agent and protein polymer.

Bonding together tissue with adhesive containing polyfunctional

Highly repetitive proteins which are relatively insoluble in water are chemically modified to increase solubility. The protein is reacted with a functionalizing agent to introduce additional polar functionalities and disrupt the order of the protein. The solubility of the protein in water is increased by the chemical modification, while adhesive and surfactant properties are retained.

Chemical modification of repetitive polymers to enhance water solubility

The present invention concerns novel methods for enhancing the mechanical performance of tissue adhesives and sealants which comprises employing a primer molecule in association with a tissue adhesive or sealant, wherein the primer molecule serves to enhance the strength of the interface between the tissue and the adhesive matrix. The primer molecules described herein function to interact with collagen present in the tissue, thereby altering its characteristics to make it more amenable to bonding with the adhesive matrix. Primer molecules may be applied to the tissue independently from the tissue adhesive or sealant or may be mixed with the tissue adhesive or sealant prior to application to the tissue.

Methods of using primer molecules for enhancing the mechanical

Proteinaceous polymers having repetitive units from naturally occurring structural proteins are employed as backbones for functionalities for crosslinking to provide strongly adherent tissue adhesives and sealants. Particularly, block copolymers having repeating units of elastin and fibroin are employed having lysine substitutions in spaced apart units, where the amino group can be crosslinked using difunctional crosslinking agents. The protein polymer contains at least 40 weight percent of repetitive units of 3 to 15 amino acids of at least one naturally occurring protein and in at least two units an amino acid is substituted by an amino acid containing a functional group capable of reacting with a crosslinking agent to form a strongly adherent adhesive composition for bonding together separated tissue or for sealing tissue defects. A preferred adhesive composition contains glutaraldehyde or polymethylene diisocyanate and a protein block copolymer of at least 30 kD containing at least 70 weight percent of repetitive units of Gly-Ala-Gly-Ala-Gly-Ser and Gly-Val-Gly-Val-Pro, where in at least two units an amino acid is substituted with lysine and the copolymer has a lysine equivalent weight in the range of 1 to 20 kD. The protein polymer is produced by recombinant DNA technology, and a kit can be formed containing the crosslinking agent and protein polymer.

Thermoplastics interdispersed with a variety of functional thermostable proteins and methods for their production are provided. To prepare the subject thermoplastics, a plastic material is contacted with a thermostable polypeptide and then subjected to the heating and molding/extrusion/casting process. The resultant thermoplastics comprise the thermostable polypeptide on the formed plastic surface and at a depth below the plastic surface. The thermostable polypeptides contained in the disclosed compositions retain functional properties or binding specificities through the heating and molding/extrusion/casting processes. Preferred thermostable polypeptides used in the disclosed compositions include silk-like protein polymers, particularly ProNectin.RTM.F. The disclosed methods and compositions find use in many applications where plastics containing finctional thermostable proteins are desired, in particular, cell cultureware.

Protein-enriched thermoplastics

Thermoplastics interdispersed with a variety of functional thermostable polypeptides, including proteins, and methods of making such thermoplastics are provided. The disclosure demonstrates that certain polypeptides can retain functional activity through exposure to plastic thermomolding. The polypeptides are exposed to the heating and molding/extrusion/casting process and are hence present on the formed plastic surface and at a depth below the plastic surface. The polypeptides contained in the disclosed compositions retain functional properties or binding specificities through the heating and molding/extrusion/casting processes. Preferred thermostable polypeptides used in the disclosed compositions include silk-like protein polymers, particularly ProNectin.RTM.F. The disclosed methods and compositions find use in many applications where plastics containing functional thermostable polypeptides are desired, in particular, cell cultureware.

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San Clemente, CA, United States of America

Erwin R Stedronsky