Implant for articular cartilage repair

1. An implant for articular cartilage repair, comprising a three-dimensional body formed of cancellous bone and having a demineralized section formed by demineralization, the demineralized section containing bone morphogenetic proteins (BMP's) that are released by the demineralization but retained in said body, and a cartilage layer formed on a surface of the demineralized section, said cartilage layer being formed by a method including the steps of:

(a) isolating chondrocytes from articular cartilage of a donor;

(b) cultivating the isolated chondrocytes in a medium;

(c) suspending the cultivated chondrocytes in agarose;

(d) adding the cultivated chondrocytes to the demineralized section of said body, whereby the cultivated chondrocytes are stimulated by the BMPs retained in said body; and

(e) incubating the cultivated chondrocytes to form a plurality of layers of chondrocytes on the demineralized section, wherein the plurality of layers of chondrocytes forms said cartilage layer.

2. The implant as claimed in claim 1 , wherein the chondrocytes are allograft chondrocytes.

3. The implant as claimed in claim 2 , wherein the donor is less than 50 years of age.

4. The implant as claimed in claim 2 , wherein the donor is alive.

5. The implant as claimed in claim 2 , wherein the donor is deceased.

6. The implant as claimed in claim 1 , wherein the demineralized section has a depth of approximately 2 mm.

7. The implant as claimed in claim 6 , wherein said body includes a mineralized section and a boundary layer formed between the demineralized section and the mineralized section, the boundary layer having a thickness of about 50 microns.

8. The implant as claimed in claim 1 , wherein said body includes pores having a size that ranges from 10 to 100 microns.

9. The implant as claimed in claim 1 , wherein step (b) includes expanding the chondrocytes in a two-dimensional culture until the chondrocytes are dedifferentiated.

10. The implant as claimed in claim 1 , wherein step (e) is performed until said cartilage layer has a thickness of approximately 2.0 mm.

11. The implant as claimed in claim 1 , wherein the plurality of layers of chondrocytes includes four layers.

12. The implant as claimed in claim 1 , wherein the chondrocytes are autograft chondrocytes.

13. The implant as claimed in claim 1 , wherein said body is formed of allograft cancellous bone.

14. The implant as claimed in claim 1 , wherein step (b) includes placing the surface of the demineralized section in a culture vessel and preparing the surface of the demineralized section for cell seeding by coating the surface with poly-L-lysine.

15. The implant as claimed in claim 1 , wherein step (e) is performed until said cartilage layer has a thickness in a range of from 2 mm to 5 mm.

16. The implant as claimed in claim 1 , wherein said body includes pores having a size that represents a multiple of the cell volume of a chondrocyte.

17. The implant as claimed in claim 1 , wherein step (e) is performed for a period of at least 40 days.

18. The implant as claimed in claim 1 , wherein the cell density of the chondrocytes in said cartilage layer is about 10 million cells per cm 3 .

19. The implant as claimed in claim 1 , wherein all of said body is demineralized.