Preparation and evaluation of acellular sheep periostea for guided bone regeneration

The objective of this study was to fabricate an acellular sheep periosteum and explore its potential application in guided bone regeneration. Sheep periosteum was collected and decellularized by a modified decellularization protocol. The effectiveness of cell removal was proved by hematoxylin and eosin and 4',6-diamidino-2-phenylindole staining, DNA quantitative test, and agarose gel electrophoresis. After decellularization, its microstructure was found to become more porous while the integrality of collagen fibers remained undamaged, and the contents of collagen and glycosaminoglycan were not decreased significantly. Biomechanical analysis showed that the elastic modulus was significantly declined, while the yield stress was not affected, probably due to the collagen integrality. In vitro study of CCK-8 assay demonstrated that the acellular periosteum not only had no toxic effect to the MC3T3-E1 cells, but benefited the cell proliferation to some degree. In vivo experiment of guided bone regeneration was performed using a rabbit cranial model. Micro-CT and histological results revealed that the acellular periosteum not only effectively prevented the ingrowth of fibrous connective tissues, but also potentially facilitated bone regeneration. In conclusion, acellular sheep periostea, with wider sources, less costs, and more convenient fabrication process, would have great potential in the employment for guided bone regeneration.