US 4,787,900 A · Process for forming multilayer bioreplaceable blood vessel prosthesis

Abstract

Process for forming a multilayer blood vessel prosthesis. Each layer is formed from bioreplaceable materials which include those produced by contacting collagen with an aminopolysaccharide and subsequently covalently crosslinking the resulting polymer, polymers of hydroxyacetic acid and the like. Cross flow filtration molding and wet extrusion molding are two processes which are particularly useful for forming the inner layer of the blood vessel prosthesis. The outer layer of the blood vessel prosthesis is preferably formed by freeze drying a dispersion of the bioreplaceable material onto the inner layer(s). The disclosed blood vessel prosthesis is a multilayer structure with each layer having a porosity and other physicochemical and mechanical characteristics selected to maximize the effectiveness of the blood vessel. The prosthesis functions initially as a thromboresistant conduit with mechanical properties which match those of the adjacent natural blood vessel. Eventually, the prosthesis functions as a regeneration template which is replaced by new connective tissue that forms during the healing process following attachment of the prosthesis.

Claims14

Dependent claims

A process for forming a blood vessel prosthesis comprising:

A. forming a generally tubular non-porous inner layer of a covalently cross-linked reaction product of collagen and an amino polyssccharide wherein the inner layer is at least 0.1 to 5 mm thick and has a relatively smooth inner surface with a number average molecular weight between cross-links of between 5,000 and 10,000 and an average pore diameter of less than 10 microns;
and
B. thereafter forming an outer layer of a collagen-aminopolysaccharide polymer wherein the outer layer has a thickness of at least 1.0 mm and is crosslinked to produce a porous bioreplaceable outer surface with a number average molecular weight between cross-links of between 10,000 and 20,000 and mean pore diameter of 50 microns or greater.

Dependencies are inferred from the claim text.

Process for forming multilayer bioreplaceable blood vessel prosthesis

Life of this patent

Process for forming multilayer bioreplaceable blood vessel prosthesis

Life of this patent

Abstract

Claims14