Comparison of the physical properties and in vivo bioactivities of silkworm-cocoon-derived silk membrane, collagen membrane, and polytetrafluoroethylene membrane for guided bone regeneration

Abstract

The aim of this study was to evaluate silkworm-cocoon-derived silk membrane (SM) for application in guided bone regeneration (GBR) and to compare it with commercially available GBR membranes, such as collagen membrane (CM) and polytetrafluoroethylene membrane (PM). The SM, CM, and PM membranes were examined via scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) analysis, and tensile strength evaluation. Thirty rats were used for the experiments. Critical-sized parietal bone defects (diameter: 8.0 mm) were divided into three groups according to the applied GBR membrane. The rats were sacrificed 4 or 8 weeks after surgery and evaluated by micro-computerized tomography (μ-CT) and histology. The FTIR analysis of the SM was similar to that of the CM. The SEM images showed that the surface characteristics of the SM differed from those of the CM and PM. The SM showed a complex network structure of silk fibers. The wet SM was also more resistant to tensile stress than the wet CM and PM. The μ-CT results of the animal study showed that the bone volume of the SM group was higher than those of the CM and PM groups 4 weeks after the operation (p<0.05). The histological analysis showed that the new bone regeneration of the SM group was higher than those of the CM and PM groups 4 and 8 weeks after the operation (p<0.05). This study demonstrated that the tensile strength of the wet SM was higher than the tensile strength of the wet CM and PM groups. The bone formation of the SM group was higher than those of the other two groups.