Recent Patents on Stem Cell-Mediated Cartilage Regeneration and Repair

It has been challenging to develop methods that induce the repair and regeneration of cartilage because of the unique characteristics of this tissue. Cartilage lacks blood vessels and lymphatic nerve systems. Moreover, chondrocytes are fed by diffusion via the perichondrium, which is helped by the pumping action generated by compression of the articular cartilage or flexion of the elastic cartilage. Thus, compared to other tissues, the growth and repair of cartilage are slow. Moreover, it is now widely understood that the physiological development and maintenance of chondrocytes, particularly those in articular cartilage, are dictated by mechanical forces. Consequently, to generate cartilage-like constructs in vitro and cartilage repair in vivo for tissue engineering and regenerative medicine purposes, these cartilagespecific characteristics, including the dependence of chondrocytes on mechanical forces, have to be considered. In recent times, the ability of stem cells to promote tissue regeneration has been the subject of great interest. Thus, in this review, we focus on stem cell-based methods of inducing cartilage regeneration and repair, and show that a deeper understanding of chondrocyte biology and mechanophysiology may lead to novel patents in this field in the future.