Bioelectric effect of a chitosan bioelectret membrane on bone regeneration in rabbit cranial defects

In this study, the effects of a chitosan bioelectret membrane on bone regeneration in a rabbit cranial defect model were examined. The bioelectret was fabricated by film casting and polarized by grid-controlled corona charging (−1 kV). In vitro, the equivalence surface charge density of the bioelectret gradually reduced under both wet and dry conditions. In vivo, two rectangular transosseous defects of 8 mm × 10 mm were created symmetrically on each rabbit cranial bone. The defects were treated with the bioelectret membrane, with unpolarized membrane, and no membrane, respectively. The rabbits were killed at 4, 8, and 12 weeks postoperatively, and specimens were examined by micro-computed tomography and histological analysis. The bioelectret membrane recipients had a significantly higher volume of newly formed bone and greater rate of material degradation than the unpolarized membrane. Furthermore, the bioelectret membrane induced new bone formation not only around the host bone but also in the center of the defects. The chitosan bioelectret membrane application has an apparent potential in guided bone regeneration applications.