Bioreactor strategies for tissue-engineered osteochondral constructs: Advantages, present situations and future trends

The aim of osteochondral tissue engineering is to achieve the complex, functional and three-dimensional tissue regeneration under well defined, controlled and reproducible conditions in vitro. To achieve tissue-engineered products in vitro that incorporate rapidly in vivo with healthy tissue, it is essential to develop highperformance cell/scaffold culture systems that mimic the dynamics of the in vivo environment. Bioreactors could provide specific physicochemical culture environment, suitable mechanical stimulation and controlled condition for the development of osteochondral constructs in vitro. This review highlighted the multifunction of bioreactor in tissue engineering, and presented microenvironment and biomechanics of native osteochondral tissue, to illustrate the necessity of establishing osteochondral constructs by bioreactor. Then, we especially emphasized the advantages and limitations of various bioreactors. Furthermore, we systematically summarized and discussed the development of bioreactor-based production systems for bone, cartilage and osteochondral tissue engineering in recent years. Finally, we made a simple conclusion and offered perspectives of bioreactorbased osteochondral tissue engineering. This review aims to serve as a reference for incorporating bioreactor strategies which could provide mechanical stimulation and physicochemical culture environment into the osteochondral construct culture regimens.