Joint cartilage shows a very limited capacity for self-repair. Full thickness cartilage injuries penetrating the subchondral bone plate do show self-repair, but the repair cartilage consists mostly of fibrous cartilage.
One out of ten patients seeking medical help due to knee pain has a significant cartilage injury.
Approximately 50 % of these have a lesion that would benefit from and is suitable for surgical treatment. Development of new surgical strategies has introduced the use of ex-vivo expanded chondrocytes implanted as a cell suspension into the defect under a periosteal flap.
The procedure requires cartilage to be harvested from a low-weight bearing part of joint, thereby creating a small but potentially harmful defect in the cartilage. Results have been promising but few well-organized randomised studies have been performed.
Aims and methods
1. Chondrocytes differentiate when cultured adhering to plastic in a monolayer. Recent results suggest that for chondrocytes to fully redifferentiate a three-dimensional matrix/scaffold is needed.
We will try to culture chondrocytes in different scaffold materials and determine which scaffold is best in making chondrocytes redifferentiate.
Scaffolds made of hyaluronic acid, alginate or collagen are the most likely candidates.
2. Chondrocytes are of mesenchymal lineage. We culture stem cells of mesenchymal lineage derived from bone marrow, synovial or adipose tissue. We investigate both scaffolds´ and growth factors´ ability to push stem cells into a chondrogenic differentiation.