In Vitro Analysis of the Differentiation Capacity of Postmortally Isolated Human Chondrocytes Influenced by Different Growth Factors and Oxygen Levels.

OBJECTIVE: In the present in vitro study, we analyzed the chondrogenic differentiation capacity of human chondrocytes postmortally isolated from unaffected knee cartilage by the addition of transforming growth factor-ß1 (TGF-ß1) and/or insulin-like growth factor-1 (IGF-1) and different oxygen levels. DESIGN: After 14 and 35 days, DNA concentrations and protein contents of Col1, Col2, aggrecan as well as glycosaminoglycans (GAGs) of chondrocytes cultivated as pellet cultures were analyzed. Additionally, expression rates of mesenchymal stem cell (MSC)-associated differentiation markers were assessed in monolayer cultures. RESULTS: All cultivated chondrocytes were found to be CD29+/CD44+/CD105+/CD166+. Chondrocytic pellets stimulated with TGF-ß1 showed enhanced synthesis rates of hyaline cartilage markers and reduced expression of the non-hyaline cartilage marker Col1 under hypoxic culture conditions. CONCLUSIONS: Our results underline the substantial chondrogenic potential of human chondrocytes postmortally isolated from unaffected articular knee cartilage especially in case of TGF-ß1 administration.