Blood contact surfaces using extracellular matrix synthesized in vitro

• US 5,908,449 A
• Filed: 04/04/1996
• Issued: 06/01/1999
• Est. Priority Date: 04/29/1994
• Status: Expired due to Term

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Begovac, Paul Christopher, Bruchman, William Carl
• Primary Examiner(s): ISABELLA, DAVID J
• Application Number:
  US08/627,640
• Time in Patent Office: 1,153 Days
• Field of Search: 623/1, 623/2, 623/11, 623/12, 623/66, 600/36, 435/240.23, 435/240.242, 435/177, 435/180, 424/424, 424/422
• US Class Current: 128/898
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61L 27/507 for artificial blood vessels apparatus for applying cells on a blood vessel prosthesis A61F2/062
• CPC Class Codes: Y10S 623/916 Blood vessel

Abstract

This invention is directed to improved blood contact devices such as vascular prostheses rendered substantially nonthrombogenic through addition of a preserved layer of extracellular subendothelial matrix. The preserved subendothelial matrix layer, which serves as the blood interface of the device, is analogous to the subendothelial matrix layer beneath the endothelium of native vascular surfaces. The device consists of a permanent synthetic base material, preferably porous expanded polytetrafluoroethylene, on which this biologic layer of subendothelial matrix is grown in situ. The biologic layer is produced using in vitro tissue culture methods whereby living cells synthesize and deposit extracellular matrix components, after which the cells are killed and/or removed and the subendothelial matrix layer preserved before implantation. A key aspect of this invention is that no living cells are present in the final configuration, so that the likelihood of recipient immunological response is minimized. This invention results in vascular prostheses that are particularly useful for arterial bypass requiring a diameter of 6 mm or less.

Claims

1. A blood contact material wherein the material is formed through the following process:

culturing a first layer of smooth muscle cells on a synthetic base material;

culturing on the first layer of smooth muscle cells a layer of endothelial cells, the interaction of the smooth muscle cells and the endothelial cells forming a subendothelial matrix layer;

stripping the endothelial cell layer from the subendothelial matrix layer to produce a second layer comprised of a subendothelial matrix layer substantially free of endothelial cells; and

employing the second layer as a direct blood contact surface.

2. The process of claim 1 which further comprises:

removing the second layer from the smooth muscle cells; and

applying the second layer to a separate synthetic base material or recipient vascular tissue for use as a direct blood contact surface.

3. The process of claim 1 wherein the synthetic base material is selected from the group consisting of at least one of polytetrafluoroethylene, polyethylene terepthalate, fluorinated ethylene propylene, polyethylene, polypropylene, and siloxane.

4. The process of claim 1 which further comprises:

stripping the endothelial cell layer from the subendothelial matrix layer by treating the endothelial cell layer with a stripping solution.

5. The process of claim 4 wherein the stripping solution is selected from at least one of a group consisting of ammonium hydroxide, chloroform, methanol, and sodium chloride.

6. A blood contact material wherein the material is formed through the following process:

culturing a first layer of smooth muscle cells on a synthetic base material;

culturing on the first layer of smooth muscle cells a layer of endothelial cells, the interaction of the smooth muscle cells and the endothelial cells forming a subendothelial matrix layer;

stripping the endothelial cell layer from the subendothelial matrix layer to produce a second layer comprised of a subendothelial matrix layer substantially free of endothelial cells;

preserving the second layer; and

employing the preserved second layer as a direct blood contact surface.

7. The process of claim 6 which further comprises:

removing the second layer from the smooth muscle cells; and

applying the second layer to a separate synthetic base material or recipient vascular tissue for use as a direct blood contact surface.

8. The process of claim 6 wherein the synthetic base material is selected from the group consisting of at least one of polytetrafluoroethylene, polyethylene terepthalate, fluorinated ethylene propylene, polyethylene, polypropylene, and siloxane.

9. The process of claim 6 which further comprises:

stripping the endothelial cell layer from the subendothelial matrix layer by treating the endothelial cell layer with a stripping solution.

10. The process of claim 9 wherein the stripping solution is selected from at least one of a group consisting of ammonium hydroxide, chloroform, methanol, and sodium chloride.

11. A method for producing a direct blood contact material which comprises:

providing a layer of smooth muscle cells;

culturing on the layer of smooth muscle cells a layer of endothelial cells;

allowing a subendothelial matrix layer to form between the smooth muscle cells and the endothelial cells;

stripping away from the endothelial cell layer to expose the subendothelial matrix layer overlaying the smooth muscle cell layer; and

employing the subendothelial matrix as the direct blood contact surface.

12. The method of claim 11 which further comprises:

forming the subendothelial matrix layer into a tubular appliance, the subendothelial matrix layer comprising an interior conduit for the appliance through which blood will flow.

13. The method of claim 11 which further comprises:

stripping away the endothelial cell layer by treating with a stripping solution.

14. The method of claim 13 wherein the stripping solution comprises an aqueous stripping solution of ammonium hydroxide at a concentration ranging from about 0.0 1 M to about 0.5 M.

15. The method of claim 11 that further comprises:

stripping away the endothelial cell layer by freeze-thaw treating the endothelial cell layer.

16. The method of claim 11 which further comprises:

stripping the endothelial cell layer by air dry treating the endothelial cell layer.

17. The method of claim 11 which further comprises:

removing the subendothelial matrix layer from the smooth muscle cell layer; and

applying the subendothelial matrix layer to an appliance to serve as a direct blood contact surface thereon.

18. The method of claim 11 which further comprises:

preserving the exposed subendothelial matrix layer; and

employing the preserved subendothelial matrix layer as a direct blood contact surface.

19. The method of claim 11 which further comprises:

treating the subendothelial matrix layer with a fixative solution to preserve the subendothelial matrix layer.

20. The method of claim 19 wherein the fixative solution is ethanol.

21. The method of claim 19 wherein the fixative solution is glutaraldehyde.

22. The method of claim 18 which prior to preserving the exposed subendothelial matrix layer further comprises:

removing the subendothelial matrix layer from the smooth muscle cell layer; and

applying the subendothelial matrix layer to an appliance to serve as a direct blood contact surface thereon.

23. A method of making an implantable material having at least one blood contact surface comprising:

procuring vascular smooth muscle cells from a blood vessel;

placing the vascular smooth muscle cells onto a surface of a synthetic base material to form a coating of vascular smooth muscle cells thereon;

applying endothelial cells to the coating of vascular smooth muscle cells to form a layer of endothelial cells on the vascular smooth muscle cells;

culturing a subendothelial matrix layer between the endothelial cell layer and the vascular smooth muscle cell coating;

removing the endothelial cell layer to expose the subendothelial matrix layer overlying the smooth muscle cell layer, the subendothelial matrix layer being suitable for use as a direct blood contact surface.

24. The method of claim 23 which further comprises:

implanting the synthetic base material having the, coating of vascular smooth muscle cells and a subendothelial matrix layer applied thereto, so as to position the subendothelial matrix layer as a direct blood contact surface.

25. The method of claim 23 which further comprises:

removing the subendothelial matrix layer and applying the subendothelial matrix layer to the surface of another synthetic base material.

26. The method of claim 23 which further comprises:

providing synthetic base material in a form selected from a group consisting of a tubular form, the form of a sheet, a spherical form, and the form of a hollow container.

27. The method of claim 26 which further comprises:

providing the synthetic base material in the form of a porous polytetrafluoroethylene.

28. The method of claim 23 which further comprises:

culturing the vascular smooth muscle cells on the surface of a tube of porous polytetrafluoroethylene.

29. The method of claim 23 which further comprises:

culturing the vascular smooth muscle cells on the surface of a sheet of porous polytetrafluoroethylene.

30. The method of claim 23 which further comprises:

preserving the subendothelial matrix layer, the preserved subendothelial matrix layer being suitable for use as a direct blood contact surface.

31. The method of claim 30 which further comprises:

implanting the synthetic base material having the coating of vascular smooth muscle cells and a preserved subendothelial matrix layer applied thereto, so as to position the preserved subendothelial matrix layer as a direct blood contact surface.

32. The method of claim 30 which further comprises:

removing the subendothelial matrix layer and applying the subendothelial matrix layer to the surface of another synthetic base material, prior to preserving the subendothelial matrix layer.