Cell-support matrix having narrowly defined uniformly vertically and non-randomly organized porosity and pore density and a method for preparation thereof

1. A cell-supporting matrix having a substantially vertically organized porosity, said matrix comprising:

(i) a substantially homogeneous vertical pore orientation, wherein at least 85% of the pores in the matrix are pores oriented in a vertically-organized arrangement;

(ii) a basal surface having pores; and

(iii) an apical surface having pores,

wherein at least 85% of said pores at the basal surface and at least 85% of said pores at the apical surface have a diameter of 200±100 micrometers; and

wherein said surfaces have a pore density of 25±10 pores per mm 2 ; and

wherein the matrix is prepared by precipitating a collagenous or collagen peptide containing biocompatible polymeric material.

2. The matrix of claim 1 wherein at least 95% of said basal and apical pores have diameters of 200±100 micrometers.

3. The matrix of claim 1 wherein at least 98% of said basal and apical pores have diameters of 200±100 micrometers.

4. The matrix of claim 1 wherein at least 85% of said basal pores and at least 85% of said apical pores are 200±50 micrometers in diameter.

5. The matrix of claim 1 wherein the collagenous or collagen peptide containing biocompatible polymeric material is selected from the group consisting of Type I collagen, Type II collagen, Type IV collagen, collagen containing proteoglycan, collagen containing glycosaminoglycan, collagen containing glycoprotein, alpha 1 Type I collagen peptide, alpha 2 Type I collagen peptide, and a combination thereof.

6. The matrix of claim 5 wherein said polymeric material is Type I collagen.

7. The matrix of claim 1 prepared by polymerizing a solution of Type I collagen comprising from 4 mg to 8 mg of Type I collagen per milliliter of solution.

8. The matrix of claim 7 wherein said solution comprises from 4 mg to 6 mg of Type I collagen per milliliter of solution.

9. The matrix of claim 8 wherein said solution comprises a non-ionic surfactant, and said Type I collagen is polymerized in the presence of a 3% aqueous ammonia solution.

10. The matrix of claim 9 wherein said solution comprises about 0.3% by weight of polyoxyethylenepolyoxypropylene block co-polymer surfactant.

11. The matrix of claim 9 wherein said Type I collagen is polymerized at a pressure between 3 torr and 10 torr.

12. The matrix of claim 9 wherein said Type I collagen is polymerized in an inert atmosphere.

13. The matrix of claim 12 wherein said Type I collagen is polymerized in nitrogen or argon atmosphere.

14. The matrix of claim 9 prepared by polymerizing said solution comprising 4 mg of Type I collagen per milliliter of solution, wherein said surfactant is polyoxyethylene-polyoxypropylene block co-polymer surfactant, in the presence of about 3% aqueous ammonia at a pressure of 3 torr of nitrogen.

15. A cell-supporting matrix prepared by a process comprising:

polymerizing a solution of Type I collagen comprising from 4 mg to 8 mg of Type I collagen per milliliter of solution in the presence of about 3% aqueous ammonia, at a pressure between 3 torr and 10 torr of an inert atmosphere;

wherein said collagen solution comprises a non-ionic polyoxyethylene-polyoxypropylene block co-polymer surfactant at a concentration of about 0.3%, by weight,

wherein said matrix has a substantially homogeneous vertical pore orientation, and at least 85% of the pores in the matrix are oriented in a vertically-organized arrangement;

wherein at least 85% of said pores at a basal surface of said matrix and at least 85% of pores at an apical surface of said matrix are 200±100 micrometers in diameter; and

wherein said surfaces have a pore density of 25±10 pores per mm 2 .

16. The matrix of claim 15 wherein said pores are 200±50 micrometers in diameter.

17. The matrix of claim 15 wherein said inert atmosphere comprises nitrogen or argon.

18. The matrix of claim 15 wherein said solution comprising 4 mg of Type I collagen per milliliter of solution is polymerized under a nitrogen atmosphere at a pressure of 3 torr.