Modification of an Injectable Chitosan Scaffold by Blending with NaHCO3 to Improve Cytocompatibility

The chitosan/beta-glycerophosphate (C/GP) system, which allows injection at room temperature and gel-formation at body temperature, can be considered as a candidate for injectable scaffolds. To improve the cytocompatiblity of the C/GP hydrogel, we used NaHCO3 as buffer to neutralize chitosan solution and lower the GP concentration from 400 to 135 mM. The chitosan/beta-glycerophosphate//NaHCO3 (C/GP/NaHCO3) system was liquid before injection and became a three-dimensional porous hydrogel at body temperature, as revealed by scanning electron microscopy (SEM). The C/GP/NaHCO3 hydrogels showed higher cytocompatibility with rat bone marrow-derived mesenchymal stem cells (rBMSCs) in vitro compared to C/GP hydrogels. Our results indicated that the C/GP/NaHCO3 system was suitable as an injectable scaffold for tissue engineering.