Fabrication of carboxymethyl chitosan-strontium chondroitin sulfate composites for potential bone regeneration

Large bone defects have been a major healthcare concern. These defects are difficult to heal because of the chronic inflammatory environment surrounding the injury area. Osteoconductive composites with anti-inflammatory effects could provide a substrate to support cell growth and guide bone defect repair. Here, we synthesized a biofunctional composite that combined carboxymethyl-chitosan (CMCS) and strontium chondroitin sulfate (SrCS), for potential use in bone regeneration. We hypothesized that the as-prepared CMCS-SrCS composites could stimulate osteogenic activity and suppress inflammatory responses. The resultant composites displayed uniformly porous structures and good swelling capacity. The effect of the composites on MC3T3-E1 cells was investigated in vitro and the live cells showed favorable viability. Moreover, the RT-PCR results indicated that the CMCS-SrCS composites could suppress inflammatory responses and promote the osteogenic differentiation of MC3T3-E1 cells. These results suggested the CMCS-SrCS composites should have osteoconductive characteristics. Thus, we believe that the developed CMCS-SrCS composites should be a promising skeletal candidate for regenerative engineering applications.