Tissue engineering of articular cartilage has always been a major focus of interest in regenerative medicine. Despite considerable progress, and some of the strategies being at a routine clinical stage, the real breakthrough in cartilage repair with satisfying long-term clinical results, has still not been achieved.
This review provides an overview of the current basic and clinical research strategies in cartilage regeneration. In addition to the available cell types, several natural and synthetic scaffolds including their respective performance in in vitro cartilage formation and in vivo cartilage regeneration are described. Moreover, bioreactor systems that mimic the mechanical loading of articular cartilage, either to provide an additional stimulus for tissue maturation prior to implantation or to study the effects of mechanical forces on cells for cartilage repair, are demonstrated.
Limitations of the current strategies are highlighted and discussed with a special focus on integration of neocartilage into the adjacent host cartilage tissue.
As this integration still represents an ongoing hurdle, engineering strategies targeting the interfaces have been developed.