The Study On The Repair Of Osteoporotic Craniofacial Defects By Collagen/graphene Oxide/alendronate Composite Material

Objectives: To prepare a Collagen/Graphene Oxide/Alendronate composite material and explore the osteogenesis of material in vitro and the repair effects of the composite material on craniofacial bone defects in osteoporosis.Methods: Type Ι collagen(Col),graphene oxide(GO)and Alendronate(Aln)were mixed under ultrasonic and formed a drug release biomaterial after crosslinking.Its porosity and water absorption were measured,and the microstructure of the material was observed by using a scanning electron microscope.Fourier transform infrared spectrometer(FT-IR)was used to detect the component characteristics,and the structural characteristics of composite material were detected by X-ray diffractometer.The released alendronate amounts in vitro were detected through the Vanadium Molybdenum Yellow colorimetric method.Co-cultured the bone mesenchymal stem cells(BMSCs)with composite material evaluated the cell proliferation in material through fluorescein diacetate staining,then tested the osteoinduction activity of material in vitro with Alizarin Red staining.Female SD osteoporosis rat model was constructed through ovariectomized surgery.After 3 months the rats were randomly divided into 5 groups and drilled cranial defect and repaired with five different materials: blank,Col-0.05%GO,Col-0.05%GO-Aln,Col-0.2%GO and Col-0.2%GO-Aln.12 weeks later,the rats were sacrificed,and a micro-CT was played to analysis the skull.Then H&E and Masson staining evaluated the repair effects on osteoporotic bone defects.Results: Compared with control group,the Collagen/Graphene Oxide/Alendronate composite material showed a suitable microporous structure,a sustained release of alendronate in vitro.Animal experiments showed that the skull defects of rat in five groups all appeared new bone ingrowth after the implantation 12 weeks,but the new bone volume in Col-0.05%GO-Aln group was better than the counterparts of blank group,Col-0.05%GO group or Col-0.2%GO group.(P < 0.01)Conclusions: Collagen/Graphene Oxide/Alendronate composite materials have desired physical and chemical properties,and Col-0.05%GO-Aln materials exhibit an obvious anti-osteoporosis effect on bone defect.It is expected to become the new biomedical material for the treatment of osteoporotic craniofacial bone defects.