Tuning the gelation behavior and cellular response of thermo-sensitive chitosan hydrogels

Abstract

Surface functionalization of implant device is highly desirable for the long term success of surgical implant. Designing and optimization of thermo-sensitive chitosan hydrogel with combined rapid gelation time and superior osteoblastic response are critical for easy intraoperative functionalization and long term osseo-integration of orthopedic implant. To this aim, the chitosan hydrogels were prepared via coupled ionic and covalent crosslinking to optimize the gelation time and the cellular responses. Different amounts of carboxymethylchitosan (CMCS, 20%, 60% and 100% (V/V)), used as a covalent crosslinking system, were mixed with the thermal-sensitive chitosan that was crosslinked by β-glycerophosphate disodium salt hydrate (CS, ionic crosslink system). The incorporation of CMCS component overall significantly improved the biocompatibility and stability of the hybrid hydrogel. The optimized CMCS/CS-0.6 sample not only maintained the thermo-sensitive character with even shorter gelation time, but also exhibited well improved biological activity and chemical stability. Such findings will have important implication in designing functionalized implants with potentials of both convenient intraoperative functionalization procedures and the long term stability and fixation of bone-implant surface.