An improved complex gel of modified gellan gum and carboxymethyl chitosan for chondrocytes encapsulation

Gellan gum is a candidate material for cartilage tissue engineering, but its application is limited by the high gelation (Coutinho et al., 2010) temperature and lack of mechanical strength. In this study, oxidized gellan gum was prepared and mixed with carboxymethyl chitosan to form a double-network complex hydrogel with significantly improved gelation temperature (Tgelation) and mechanical properties. The Tgelation was lowered from 42 °C to below physiological temperature by oxidation, and further reduced by complexing with carboxymethyl chitosan. The complex hydrogel showed an increased compressive modulus of 278 kPa, and an ability to return to the original shape after release of the compressive load. In vitro chondrocytes encapsulation and proliferation experiments found that the complex hydrogel significantly enhanced the viability of the cells. These results suggest that, the complex gel of gellan gum and carboxymethyl chitosan is a promising material for cartilage tissue engineering.