Abstract: Objective To observe whether there are mesenchymal stem cells in the articular cartilage, and identify the cartilage-derived stem cells. Methods The isolated single chondrocytes digested from cartilage tissue were seeded onto the fibronectin coated plates .After 20 mins, media and non-adherent cells were removed, fresh media were added to the remaining adherent cells. 2 weeks after plating , colonies were selected and isolated using sterile cloning rings. Then we detected the surface markers with flow cytometry and verified the ability of adipogenic, osteogenic and chondrogenic differentiations of the cells. Results The morphological feature of the third passage’s cartilage-derived stem cells displayed an uniform fibroblast-like phenotype. The cells were positive for many stem cells markers, including CD44、CD29、CD73、CD90 、CD166, and negative for CD45 、CD34and CD133,as shown by flow cytometry. Adipogenic, osteogenic and chondrogenic differentiations were revealed in cartilage-derived stem cells when cultured in specific medium． Conclusion There are mesenchymal stem cells in human articular cartilage, and we have isolated and identified the cartilage-derived stem cells successfully.

Key words: articular cartilage , stem cells , repair