Cartilage regeneration using biodegradable oxidized alginate/hyaluronate hydrogels.

Despite the widespread use of alginate (AL) hydrogels in many biomedical applications, including tissue engineering, AL is inherently non-degradable under physiological conditions. We hypothesized that degradable alginate (dAL) would be useful for cartilage regeneration when combined with hyaluronate (HA). We prepared dAL by partial oxidation of AL using sodium periodate, and the degradation rate of AL hydrogel was able to be regulated by control of sodium periodate concentration. The degradable oxidized AL/HA gels were formed in the presence of cells and their characteristics were investigated. dAL/HA gels with primary chondrocytes were injected subcutaneously into mice. Effective cartilage regeneration was observed after 6 weeks of transplantation based on histological analysis. Moreover, substantial secretion of sulfated glycosaminoglycans and expression of chondrogenic marker genes were also observed compared with non-dAL/HA gels. These results indicate that dAL/HA hydrogels may be useful in cartilage regeneration, and in many tissue engineering applications.