**6. Conclusions**

MSCs and concomitant derivatives have emerged as advantaged and alternative sources for OA administration and cartilage repair. MSC- or MSC-exo/sEVs- laden biomaterial systems have supplied overwhelming new tissue-engineering platforms to sequentially improve the osteochondral interface and alleviate the full-thickness articular cartilage defects, which collectively accelerates the reestablishment of osteochondral and cartilage tissues (**Table 2**). Of note, injecting MSCs into joints with


**Table 2.**

*Advances in MSC-based cytotherapy for OA.*

an inflammatory environment may elevate the risk of ectopic calcification and osteoproliferation in patients with OA. Therefore, systematic and detailed investigations are urgently needed to ensure the maintenance of the intra-articular environment for cartilage repair before large-scale application in clinical practice. In spite of the tremendous progresses in the field of OA management and MSC-based regenerative medicine, it still remains challenging and there's a long way to go to efficiently and cost-effectively repair the full-thickness articular cartilage defects and osteochondral interface via achieving efficient osteogenesis and chondrogenesis.
