Porous plasma protein matrices and methods for preparation thereof
The present invention relates to porous freeze-dried plasma protein matrices having an open channel structure and a concentration gradient of plasma proteins crosslinked by the action of thrombin, and methods of producing said matrices. The compositions of the present invention are useful clinically, per se or as cell-bearing implants.
1. A porous, freeze-dried plasma protein matrix sponge comprising plasma proteins crosslinked by the action of thrombin, having two opposing surfaces substantially parallel to the horizontal axis of the matrix and at least one additional surface extending along the periphery of the sponge substantially parallel to the vertical axis, wherein the plasma proteins and the thrombin are present in gradients having a higher concentration along one of the opposing surfaces and, wherein the average size of the pores in cross section is smaller along the surface of the matrix exposed to the higher concentration of thrombin.
2. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein the thrombin is introduced at a concentration of about 300 IU/ml to about 1,500 IU/ml.
3. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein the thrombin is introduced at a concentration of about 500 IU/ml to about 1000 IU/mi.
4. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein the plasma proteins and thrombin are present in a ratio of about 5:1 (v/v) to about 50:1 (v/v).
5. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein the plasma proteins and thrombin are present in a ratio of about 8:1 (v/v) to about 30:1 (v/v).
6. The porous freeze-dried plasma protein matrix sponge according to claim 1 , the pores having an average size of about 5 μm to about 30 μm in cross section in the fraction of the matrix exposed to the higher concentration of thrombin.
7. The porous freeze-dried plasma protein matrix sponge according to claim 1 , the pores having an average size of about 10 μm to about 20 μm in cross section in the fraction of the matrix exposed to the higher concentration of thrombin.
8. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein the plasma proteins crosslinked by the action of thrombin are generated by a thrombin solution comprising at least one viscosity-enhancing agent selected from a protein, a glycosaminoglycan, a polysaccharide, disaccharide and a synthetic polymer.
9. The porous freeze-dried plasma protein matrix sponge according to claim 8 , wherein the protein is an extracellular matrix protein selected from collagen, fibronectin, elastin and laminin.
10. The porous freeze-dried plasma protein matrix sponge according to claim 9 , wherein the protein is collagen.
11. The porous freeze-dried plasma protein matrix sponge according to claim 9 , wherein the polypeptide is fibronectin.
12. The porous freeze-dried plasma protein matrix sponge according to claim 8 , wherein the glycosaminoglycan is selected from crosslinked hyaluronic acid and non-crosslinked hyaluronic acid.
13. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein the plasma proteins crosslinked by the action of thrombin are generated by a thrombin solution comprising a transglutaminase.
14. The porous freeze-dried plasma protein matrix sponge according to claim 13 , wherein the transglutaminase is factor XIII.
15. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein the plasma proteins are substantially devoid of plasminogen.
16. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein the plasma proteins are substantially devoid of organic chelating agents.
17. The porous freeze-dried plasma protein matrix sponge according to claim 1 , further comprising at least one additive selected from the group consisting of a polysaccharide, a glycosaminoglycan and a synthetic polymer.
18. The porous freeze-dried plasma protein matrix sponge according to claim 17 , wherein the glycosaminoglycan is selected from crosslinked hyaluronic acid, non-crosslinked hyaluronic acid and heparin and derivatives thereof.
19. The porous freeze-dried plasma protein matrix sponge according to claim 1 , further comprising at least one bioactive agent selected from the group consisting of growth factors, cytokines, platelets, platelet supernatant and platelet derived proteins, hormones, analgesics, anti-inflammatory agents, anti-microbials and enzymes.
20. The porous freeze-dried plasma protein matrix sponge according to claim 19 , wherein the growth factor is selected from a fibroblast growth factor and variant thereof.
21. The porous freeze-dried plasma protein matrix sponge according to claim 1 , further comprising cells.
22. The porous freeze-dried plasma protein matrix sponge according to claim 21 , wherein the cells are selected from stem cells, progenitor cells, chondrocytes, osteoblasts, hepatocytes, mesenchymal cell types, endothelial cell types, epithelial cell types, urothelial cell types, endocrinal cell types, neuronal cell types, pancreatic cell types, renal cell types and ocular cell types.
23. The porous freeze-dried plasma protein matrix sponge according to claim 22 , wherein the cells are chondrocytes.
24. The porous freeze-dried plasma protein matrix sponge according to claim 22 , wherein the cells are hepatocytes.
25. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein at least one of the plasma proteins is autologous.
26. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein at least one of the plasma proteins is recombinant.
27. The porous freeze-dried plasma protein matrix sponge according to claim 1 , further comprising a fibrin fiber-modifying agent.
28. A method of preparing the porous, freeze-dried plasma protein matrix sponge of claim 1 , comprising the steps:
(a) introducing a thrombin solution to a solid receptacle or mold;
(b) layering a plasma protein solution over the thrombin solution in the solid receptacle or mold, wherein the thrombin and plasma protein solutions are introduced and layered to provide a higher concentration along one of the opposing surfaces;
(c) incubating under conditions appropriate to achieve clotting;
(d) freezing the clotted mixture; and
(e) lyophilizing the clotted mixture, to obtain a porous matrix.
29. The method according to claim 28 , further comprising the steps of:
seeding the porous matrix sponge with cells.
30. The porous freeze-dried plasma protein matrix sponge according to claim 1 , wherein the plasma proteins are allogeneic.
31. A method for facilitating cellular growth in an individual at a site in need of tissue repair or regeneration tissue, which comprises implanting the freeze-dried plasma protein matrix sponge of claim 1 at the site to provide a scaffold for cellular growth.
32. The method according to claim 31 , wherein the site is selected from one of neural, muscular, skeletal, cartilaginous, tendonous, hepatic, pancreatic, renal, ocular, arteriovenous, mammary or urinary tissue.
33. The method according to claim 31 , wherein the site is cartilage tissue.
34. The method according to claim 31 , wherein the site is hepatic tissue.
35. The method according to claim 31 , wherein the sponge further comprises cells.