Modification of an Injectable Chitosan Scaffold by Blending with NaHCO ³ to Improve Cytocompatibility

The chitosan/β-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/GPhydrogel, we used NaHCO ₃ as buffer to neutralize chitosan solution and lower the GP concentration from 400 to 135 mM. The chitosan/β-glycerophosphate//NaHCO ₃ (C/GP/NaHCO ₃ ) 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/NaHCO ₃ 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/NaHCO ₃ system was suitable as an injectable scaffold for tissue engineering.