Background - Existing therapies for joint injury and osteoarthritis generally fail to restore the biomechanical equilibrium that is critical to joint homeostasis. The potential of cartilage tissue engineering using autologous stem cells is a promising fi eld, but much remains to be understood. In particular, mechanical loading as a means of directing stem cell behaviour is an area of great interest. Methods - Exogenous scaff old-free tissue-engineered constructs were generated from human synovial membrane and/or fluid-derived mesenchymal progenitor cells from five diff erent donors. Cell monolayers were treated with either ascorbic acid-supplemented (AA) media or chondrogenic diff erentiation media, causing matrix deposition that could be aggregated into constructs. The aggregated constructs were then subjected to con fined compressive loading. Results - Constructs were successfully generated using both methods. Gene expression markers of chondrogenic diff erentiation were substantially di erent from controls, but varied dramatically between constructs and donors. The generated constructs exhibited a complex, heterogeneous structure under histological analysis that stained positively for cartilage markers regardless of loading.
Conclusions - The findings of this study likely indicate that the constructs retained their chondrogenic potential following construct generation and highlight the utility of mechanical loading in directing di fferentiation in tissue-engineered constructs. They also emphasize some of the challenges presented by the variability in donor tissues, and may serve as a useful platform for future studies investigating the generation of autologous tissue-engineered cartilage.