Treatment of critical-sized calvarial non-union defect via collagen-polyglycolic acid scaffold loading with simvastatin in rabbits

Abstract

The aim of the present study is to investigate the effects of a sustained-release simvastatin in collagen-polyglycolic acid scaffold on bone formation in the rabbit calvarial critical-sized defect. This study was carried out to examine if maximum bone regeneration with less inflammation would be attained by combining an optimal dose of simvastatin with Collagen-Polyglycolic acid scaffold, which is an osteoconductive biomaterial capable of releasing the drug slowly. To induce critical-sized calvarial defect in the 10 nominated adult New-Zealand rabbits we trephined four holes measured 5-mm-diameter into each head, and filled them with preparations of different doses of simvastatin (0.5 mg, and 1 mg) blended with Collagen-Polyglycolic acid, Scaffold alone or left empty. Five animals were sacrificed after 4 weeks and the rest of them after 8 weeks and examined histologically. Statistical analysis revealed that in the first time frame (the first four weeks), the difference between the control group and the simvastatin 0.5 mg group on one hand and the simvastatin 1 mg group and the control group on the other hand, there were statistically significant difference between (p < 0.05). In the second time frame (the next four weeks), there were statistically significant differences between the simvastatin 0.5 mg group and the control group, and between the scaffold group and the control group (p <0.05). When combined with collagen-polyglycolic scaffold, 0.5 mg simvastatin is the optimal dose for the arousal of the maximum bone regeneration in rabbit calvarial defects without causing inflammation and it could be applied as an effective bone graft material.