Multilayer bioreplaceable blood vessel prosthesis

• US 4,902,289 A
• Filed: 08/09/1988
• Issued: 02/20/1990
• Est. Priority Date: 04/19/1982
• Status: Expired due to Term

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Yannas, Ioannis V.
• Primary Examiner(s): Apley, Richard J.
• Assistant Examiner(s): Isabella, David J.
• Application Number:
  US07/230,110
• Time in Patent Office: 560 Days
• Field of Search: 623/1, 623/2, 623/10, 623/11, 623/16, 623/66
• US Class Current: 623/1.47
• CPC Class Codes: A61F 2/062 Apparatus for the production of blood vessels made from natural tissue or with layers of living cells prostheses made from natural tissue or living cells A61L27/507
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2310/00365 Proteins; Polypeptides; Degradation products thereof
• CPC Class Codes: A61L 27/26 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/10 flexible, e.g. blown foils
• CPC Class Codes: B29C 48/919 using a bath, e.g. extruding into an open bath to coagulate or cool the material
• CPC Class Codes: C08L 89/06 derived from leather or skin , e.g. gelatin
• CPC Class Codes: Y10S 623/917 Collagen

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 resluting 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 funcitons 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.

Claims

1. A multilayer blood vessel prosthesis comprising:

a first inner conduit defining a relatively smooth walled lumen, said inner layer is crosslinked aminopolysacchride ride having a mean pore diameter below 10 microns, a wall thickness between 0.1 to 5.0 mm, and a number average molecular weight between crosslinks of between 2000 and 12,000 daltons and

a second outer layer on said first layer, said outer layer formed a crosslinked freeze dried collagen-aminopolysascharide polymer having a mean pore diameter of at least 50 microns and a thickness of at least 1.0 mm.

2. The blood vessel prosthesis as set forth in claim 1 wherein the collagen-aminopolysaccharide comprises from 1 to 15% aminopolysaccharide.

3. The blood vessel prosthesis as set forth in claim 1 wherein the aminopolysaccharide is selected from a number of the group consisting of chondroitin-4-sulfate, chondroitin 6-sulfate, heparin sulfate, dermatan sulfate, keratan sulfate, heparin, hyalurenic acid and chitosan.

4. The blood vessel prosthesis as set forth in claim 1 wherein the outer layer has been crosslinked to an average molecular weight between cross-links of between 2,000 to 60,000.

5. The blood vessel prosthesis as set forth in claim 1 wherein the prosthesis has a tubular shape.

6. The blood vessel prosthesis as set forth in claim 1 wherein the prosthesis has a bifurcated tubular shape.

7. The blood vessel prosthesis as set forth in claim 1 wherein the prosthesis has a tapered cylinder shape

8. The blood vessel prosthesis as set forth in claim 1 wherein said inner layer is seeded with cells.

9. The blood vessel prosthesis as set forth in claim 8 wherein said inner layer is seeded with endothelial cells.

10. The blood vessel prosthesis as set forth in claim 8 wherein said inner layer is seeded with smooth muscle cells.

11. The blood vessel prosthesis as set forth in claim 10 wherein said inner layer is seeded with fibroblasts.

12. The blood vessel prosthesis as set forth in claim 1 wherein said outer layer is seeded with cells.

13. The blood vessel prosthesis as set forth in claim 12 wherein said outer layer is seeded with smooth muscle cells.

14. The blood vessel prosthesis as set forth in claim 12 wherein said outer layer is seeded with fibroblasts.

15. The blood vessel prosthesis as set forth in claim 1 wherein the prosthesis is sheathed with a woven or knitted fabric.

16. The blood vessel prosthesis as set forth in claim 1 wherein the prosthesis has incorporated within it a woven or knitted fabric.