Method for repair of cartilage lesions

1. A method for repair of cartilage lesions, said method comprising steps:

a) preparing a porous support matrix containing a plurality of pores having a pore size from about 50 to about 500 μm, wherein said matrix is prepared as a porous sponge, porous scaffold, porous honeycomb or porous honeycomb-like lattice;

b) seeding said support matrix with chondrocytes isolated from a donor and suspended in a collagenous solution or collagenous gel;

c) applying a constant or cyclic hydrostatic pressure to the support matrix seeded with chondrocytes from step (b) for a period from about one hour to about 30 days followed by a resting period at a static atmospheric pressure for about one day to about 60 days,

wherein said hydrostatic pressure is from about 0.01 MPa to about 10 MPa above atmospheric pressure;

d) pre-treating a cartilage lesion by depositing a layer of a biologically acceptable bottom sealant into said lesion before implanting said seeded support matrix from step c) therein;

e) implanting said seeded support matrix from step c) into said pre-treated lesion of step d); and

f) depositing a layer of a biologically acceptable top sealant over said seeded support matrix from step c) implanted into said lesion.

2. The method of claim 1 wherein said top and said bottom sealants are the same or different.

3. The method of claim 2 wherein said top or bottom sealant is selected from the group consisting of gelatin; a copolymer of polyethylene glycol and poly-lactide; a copolymer of polyethylene glycol and poly-glycolide; periodate-oxidized gelatin; polyethylene glycol diacrylate derivatized with 4-armed pentaerythritol thiol; polyethylene glycol derivatized with 4-armed tetra-succinimidyl ester; polyethylene glycol derivatized with tetra-thiol; polyethylene glycol-co-poly(α-hydroxy acid) diacrylate macromer; 4-armed polyethylene glycol derivatized with succinimidyl ester and thiol; polyethylene glycol derivatized with alkylated collagen; polyethylene glycol derivatized with methylated collagen; polyethylene glycol derivatized with tetra-hydrosuccinimidyl; and a combination thereof.

4. The method of claim 3 wherein said sealant is polyethylene glycol derivatized with methylated collagen.

5. The method of claim 4 wherein the support matrix is prepared from a material selected from the group consisting of Type I collagen; Type II collagen; Type IV collagen; cell-contracted collagen containing material selected from the group consisting of proteoglycan, glycosaminoglycan and glycoprotein; gelatin; agarose; hyaluronin; fibronectin; laminin; bioactive peptide growth factor; cytokine; elastin; fibrin; polymeric fiber made of a polylactic acid; polymeric fiber made of a polyglycolic acid; polycaprolactone; polyamino acid; a polypeptide, and collagenous gel; a copolymer thereof and a combination thereof.

6. The method of claim 5 wherein said porous sponge, porous honeycomb, porous scaffold or porous honeycomb-like lattice is prepared from a material selected from the group consisting of Type I collagen and Type II collagen.

7. The method of claim 6 wherein said hydrostatic pressure is the cyclic hydrostatic pressure from about 0.5 MPa to about 5 MPa applied at frequency from about 0.5 Hz.

8. The method of claims 5 wherein said cyclic hydrostatic pressure is about 3.0 MPa applied at frequency of about 0.5 Hz and is applied for from about seven days to about 14 days and wherein said resting period is from about seven to about 28 days.

9. The method of claim 8 wherein said support matrix seeded with chondrocytes is submitted to the cyclic hydrostatic pressure and subjected to a flow of culture media at a flow rate from about 1 μL/min to about 500 μL/min.

10. The method of claim 9 wherein said flow rate is about 5 μL/min to about 50 μL/min and is performed in the presence of about 1% to about 20% oxygen.

11. The method of claim 10 wherein said top sealant is the derivatized polyethylene glycol cross-linked with methylated collagen and results in an outgrowth of a layer of squamous-like flattened superficial zone chondrocytes covering the top sealant and overgrowing the cartilage lesion.

12. The method of claim 5 wherein said collagenous gel is a polymeric thermoreversible gelling hydrogel.

13. The method of claim 1 wherein said cyclic hydrostatic pressure is applied at from about 0.01 to about 2.0 Hz.