Support for tissue regeneration and process for producing the same

• US 20060127368A1
• Filed: 09/09/2003
• Published: 06/15/2006
• Est. Priority Date: 09/09/2002
• Status: Active Grant

• Current Assignee: GC Corporation (General Cannabis Corp.), National Institute of Advanced Industrial Science and Technology (Government of Japan), Kaneka Corporation
• Original Assignee: GC Corporation (General Cannabis Corp.), National Institute of Advanced Industrial Science and Technology (Government of Japan), Kaneka Corporation
• Inventors: Sato, Masao, Hattori, Koji, Fukuchi, Takeshi, Kaneko, Tadashi, Ohgushi, Hajime, Uematsu, Kota, Yamashita, Kenji, Nishi, Akiko, Shimizu, Ichiro, Niwa, Hideo
• Granted Patent: US 7,445,793 B2
• Time in Patent Office: Days
• US Class Current: 424/93.700
• CPC Class Codes: A61L 2430/06 for cartilage reconstruction, e.g. meniscus
• CPC Class Codes: A61L 27/3852 Cartilage, e.g. meniscus
• CPC Class Codes: A61L 27/3895 using specific culture conditions, e.g. stimulating differentiation of stem cells, pulsatile flow conditions
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: C12N 2533/40 Polyhydroxyacids, e.g. polymers of glycolic or lactic acid (PGA, PLA, PLGA); Bioresorbable polymers
• CPC Class Codes: C12N 5/0068 General culture methods using substrates for specific animal cell type C12N5/06
• CPC Class Codes: C12N 5/0655 Chondrocytes; Cartilage

Abstract

The present invention provides a scaffold in which cells can be stably retained and grafted in a uniform distribution state in the culture, preferable proliferation ability and viability can be secured, and particularly in the case of cartilage, fixation treatment such as suture can be carried out in the transplantation into affected parts after the culture, and the mechanical strength is provided sustainable for (weighted) compression at the initial stage of transplantation. The present invention relates to a 3-dimensional porous scaffold for tissue regeneration which comprises a structure composed of vertically long-shaped pores having a pore diameter of not less than 10 μm to not more than 500 μm and pore length of not less than 20 μm to not more than 1 cm being juxtaposedly arranged obtained by a production process comprising rapid freeze-drying as a key technology. Further, the invention relates to the above 3-dimensional porous scaffold in which seeding properties of cells are improved by a pore enlargement treatment of one side face by a separation operation, a salt elution operation of a surface part, or a combination of these operations. It becomes possible to produce a 3-dimensional cell combination having excellent degree of tissue formation and medical treatment effect by seeding a cell or precursor cell derived from a tissue in this scaffold, and culturing them in an artificial environment and/or the living body.

Claims

1. A 3-dimensional porous scaffold for tissue regeneration

which comprises a structure composed of vertically long-shaped pores having a pore diameter of not less than 10 μ

m to not more than 500 μ

m and pore length of not less than 20 μ

m to not more than 1 cm being juxtaposedly arranged, and the spaces between the juxtaposed pores being communicated with small pores having a pore diameter of not more than 10 μ

m.

2. The 3-dimensional porous scaffold according to claim 1,

which has an approximately flat plate-shape with vertically long-shaped pores in the thickness direction being juxtaposedly arranged in the surface direction, and one side face being subjected to pore-opening treatment.

3. The 3-dimensional porous scaffold according to claim 2,

which is composed of a biocompatible material.

4. The 3-dimensional porous scaffold according to claim 3,

wherein the biocompatible material contains at least one selected from the group consisting of polylactic acid, polyglycolic acid, lactic acid/glycolic acid copolymer, poly ε

caprolactone, and lactic acid/ε

caprolactone copolymer.

5. A process for producing the 3-dimensional porous scaffold according to claim 1

which comprises the following steps:

a) dissolving a scaffold material in an organic solvent,

b) pouring the prepared solution into a mold, and freezing the solution at a cooling rate of not slower than 3°

C./minute, and

c) drying the frozen solution in vacuum to remove the organic solvent.

6. A process for producing the 3-dimensional porous scaffold according to claim 2

which comprises the following steps:

a) dissolving a scaffold material in an organic solvent,

b) pouring the prepared solution into a mold forming an approximately flat plate-shape, and freezing the solution at a cooling rate of not slower than 3°

C./minute,

c) drying the frozen solution in vacuum to remove the organic solvent, and

d) separating the dried scaffold in the central region of the thickness direction in the flat plate direction.

7. A process for producing the 3-dimensional porous scaffold according to claim 2

which comprises the following steps:

a) dissolving a scaffold material in an organic solvent,

b) dispersing a granular salt in a mold forming an approximately flat plate-shape,

c) pouring the prepared solution into said mold, and freezing the solution at a cooling rate of not slower than 3°

C./minute,

d) drying the frozen solution in vacuum to remove the organic solvent, and

e) removing the granular salt by washing with water.

8. The process for producing a 3-dimensional porous scaffold according to claim 7,

wherein the granular salt is a mineral salt and/or organic salt.

9. A 3-dimensional cell combination

which is obtainable by culturing a cell or precursor cell derived from a tissue in the 3-dimensional porous scaffold according to claim 1 in an artificial environment and/or the living body.

10. The 3-dimensional cell combination according to claim 9,

wherein the cell or precursor cell derived from a tissue is derived from a bone, cartilage, ligament, tendon, blood vessel, skin, fat, muscle, nerve, heart, liver, pancrea, intestine, kidney, cornea, bladder, ureter, urethra, breast, marrow, or cord blood.

11. The 3-dimensional cell combination according to claim 10,

wherein the cell or precursor cell derived from a tissue is derived from a bone, articular cartilage, ligament or tendon.

12. The 3-dimensional cell combination according to claim 10,

wherein the cell or precursor cell derived from a tissue is derived from the marrow, fat, liver, or cord blood.

13. The 3-dimensional cell combination according to claim 10,

wherein the cell or precursor cell derived from a tissue is a mesenchymal stem cell.

14. A 3-dimensional cell combination

which is obtainable by culturing a cell or precursor cell derived from a tissue in the 3-dimensional porous scaffold produced by the process according to claim 7 in an artificial environment and/or the living body, and

has a compression modulus of not less than 1/10 of the normal cartilage.

15. A 3-dimensional cell combination

which is obtainable by culturing a cell or precursor cell derived from a tissue in the 3-dimensional porous scaffold produced by the process according to claim 7 in an artificial environment and/or the living body, and

has a tissue structure more similar to the normal cartilage with the thickness from the side subjected to pore-opening treatment or side not subjected to pore-opening treatment being within the range of 1 to 90% of the whole thickness.

16. A process for producing a 3-dimensional cell combination

which comprises seeding a cell or precursor cell derived from a tissue in the 3-dimensional porous scaffold according to claim 1, and culturing the cell in an artificial environment and/or the living body.

17. The process for producing a 3-dimensional cell combination according to claim 16,

wherein the cell or precursor cell derived from a tissue is subjected to stand culture under 3-dimensional environment for 1 to 48 hours beforehand.

20. A medical treatment method of cartilage damage

which comprises transplanting the 3-dimensional porous scaffold according to claim 1, into the living body.

21. A medical treatment method of cartilage damage

which comprises transplanting the 3-dimensional cell combination according to claim 9 into the living body.

18. (canceled)

19. The process for producing a 3-dimensional cell combination according to claim 18,

wherein the culture in an artificial environment is carried out under the condition of moving a culture fluid at a rate of 0.1 to 50 cm per second relative to the scaffold.