Antler Collagen/Chitosan Scaffolds Improve Critical Calvarial Defect Healing in Rats

This study was to develop chitosan scaffolds combined with collagen derived from deer antler and test its in vivo bone regeneration capacity in the calvarial defect model. Chitosan was crosslinked with deer antler-derived collagen by chemical reaction and lyophilized to attain porous scaffolds. Untreated chitosan was taken as control. Proliferation rate of rat bone marrow-derived mesenchymal stem cells was measured at 3 or 5 day after seeded on the porous scaffold in vitro. Sprague-Dawley rats were subjected to operation to make calvarial bone critical defects. Then the defects were left empty or implanted with chitosan scaffolds, or antler collagen/chitosan (A-collagen/chitosan) scaffolds. Samples were collected for micro-CT then decalcified for histology analysis 8 weeks post-surgery. Cell proliferation was significantly enhanced when they seeded onto the A-collagen/chitosan scaffolds compared with chitosan only scaffolds. The volume of mineralized tissue was also markedly increased in the calvarial defect region when implanted with A-collagen/chitosan compared with chitosan only scaffolds. Histological results also showed more new bone forming beneath the A-collagen/chitosan scaffolds, which was consistent with that of micro-CT analysis. In conclusion, A-collagen/chitosan scaffolds showed promising reparative effect in rat critical-sized calvarial bone defect models.