Experimental Study Of Biological Silicon - Microsphere Scaffold Combined With AFDR In Repairing Rat Skull Defect

IntroductionBone defects occurs with trauma、infection、tumor, as well as a variety of congenital diseases,approximately5%-10%, the repair of bone defects is a challenging problem in clinical.The treatment for bone defect is mainly through bone grafts to fill, repair. According to the different sources, bone graft can be divided into autogenous bone graft, allograft and xenograft bone transplantation, etc. Autologous bone graft has long been regarded as the gold standard for bone graft, which because of its dual function of osteoconduction and osteoinduction, no immune rejection and heal more quickly. But due to the limited source of autogenous bone, and the immunological rejection or lack of bioactivity of allograft bone and xenogeneic bone, which clinical application is limited. In order to overcome the various problems of allograft bone, autogenous bone, and xenograft bone existing in the repair of bone defects, the ideal artificial bone repair materials by tissue engineering is a hot research topic in bone tissue engineering. Biological silicon-microsphere scaffolds, provided by the national testing center of geological experiments, is a new type of bone materials that is prepared on the basis of the biological-silicide bionic materials. The material has the function of osteoconduction, and has the similar composition with the natural bone, with certain pore space and links.The traditional Chinese medicine drynaria (DR) has many therapeutic functions,such as invigorating the kindey and spermium,strengthening tendons and bones, activating blood and dissipate blood stasis,as well as swelling and pain.It has been vertified by the contemporary pharmacological studies that assemble flavone of rhizoma drynaria(AFDR) can accelerate fracture healing, anti osteoporosis, anti-inflammatory analgesic effect, and can reduce blood lipids, improve microcirculation, has certain protective effect to the kidney, etc.Application of biological silicon-microsphere scaffolds materials to repair bone defects, combined with the use of AFDR, may enhance the ability of bone repair and reduce the trauma response. ObjectiveTo observe and compare the effect of biological silicon-microsphere scaffolds(BSMS) combined with assemble flavone of rhizoma drynaria (AFDR) in repairing bone defect, and explore the exploration and the treatment of bone defect with combination of Traditional Chinese Medicine and Western Medicine. Methods1. Histocompatibility test:12 SD rats were divided into 3 groups according to the time of sampling. Making a longitudinal incision of about 2 cm long at the side of the rat spinal back skin, then to divide the deep fascia and implant size about 5 mm x 5 mm x 2 mm biological silicon-microsphere scaffolds. To execute rats on postoperative 2,4,8 weeks time, tissue specimens were stained with Hematoxylin and Eosin (HE) which were used to observe the histological changes.2. Rat skull defect test:54 SD rats were randomly divided into three groups. Group A: BSMS+Deionized Water (DW), fed the 18 rats with DW for 4-12weeks. Group B:BSMS+ AFDR, fed the 18 rats with AFDR for 4-12weeks. Group C:Hydroxyapatite (HA)+DW, fed the 18 rats with DW for 4-12weeks. In the experiment, the diameter of the skull defect model of SD rats was about lcm, and the rats are executed at 4,8,12 weeks three time points to draw materials. HE staining and Masson staining to observe histological changes; type I collagen, alkaline phosphatase and osteocalcin immunohistochemical staining, microscope to collect images and analysis of the observation index optical density, and the index was analyzed by statistic treatment. ResultsBiological silicon-microsphere scaffolds (BSMS)+AFDR group’s histological observation shows a lot of blood vessels, fibrous tissue ingrowth the materials and a large number of osteoid tissue formation, which the effect of bone repair and the degree of dissolved materials is better than the other two groups. Alkaline phosphatase immunohistochemical average integral optical density (AIOD) value:AFDR group has statistically significant at 4 weeks,8 weeks compared with DW group and HA group, and at 12 weeks with HA group has significant differences (p<0.05). Type I collagen immunohistochemical AIOD value:AFDR group has statistically significant at 4 weeks,8 weeks and 12 weeks compared with DW group and HA group (p<0.05). Osteocalcin immunohistochemical AIOD value:AFDR group has statistically significant at 4 weeks,8 weeks and 12 weeks compared with DW group and HA group (p<0.05). Optical density value of immunohistochemical analysis showed that the positive expression of the BSMS+AFDR group is much obvious than the other two. Conclusion1. BSMS has good histocompatibility.2. BSMS combined with AFDR can effectively repair large bone defect in rats.3. BSMS combined with AFDR improve the positive expression of alkaline phosphatase, type I collagen, and osteocalcin, promote the formation and mineralization of bone matrix, thus accelerating bone repair.