Promotion of chondrogenic differentiation of mesenchymal stem cells by copper: Implications for new cartilage repair biomaterials.

Copper (Cu) has drawn considerable attention in the design of biomaterials due to its multifunction, such as antibacterial property, osteogenic and angiogenic ability. However, the effect of Cu on chondrogenic differentiation of mesenchymal stem cells (MSCs) and its potential for cartilage repair biomaterials has been rarely studied. Here, we report that Cu can significantly enhance chondrogensis of MSCs. Specifically, in vitro studies showed that Cu could promote MSCs cytoskeleton change, extracellular glycosaminoglycan (GAG) deposition and the chrodrogenic genes (Sox9, Aggrecan, and Col-2) up-regulation. Furthermore, we prepared a Cu-containing alginate (Alg) porous scaffold to assess the chondroinductivity of Cu in vivo. In eight weeks, we found that Alg/Cu scaffolds could induce better formation of new cartilage tissue compared to the pure Alg scaffolds fabricated by the same procedure but without adding Cu. These encouraging results indicate that Cu can bring considerable benefits to the development and application of cartilage repair biomaterials.