Preparation Biocompatibility Evaluation On Nano-hydroxyapatite/Collagen/RhBMP-2Scaffold

BACKGROUND:Under the theory of bone-tissue engineering, biocompatibility of biomaterial is evaluated by observing the morphous and determining the multiplication and differentiation rate of osteoblasts on biomaterials.OBJECTIVE:To observe the effects of nano-hydroxyapatite-collagen-rhBMP-2(nHAC/rhBMP-2) on proliferation and differentiation of osteoblasts.Evaluating the osteoeytes compatibility of composite materials from the area of cytology, while comparing with the allogeneic bone.To provide the basis for clinical application.METHODS:The rat osteoblasts were obtained from the cranium of newborn Wistar rats within24hours, and primarily cultured using modified collagenase digestion. The cells were generated and their biological characteristic was examined by inverted phase-contrast microscope, hematoxylin-eosin staining, alkaline phosphatase (ALP) staining and mineralized nodules staining. Then the cells at passage3were co-cultured with nHAC/rhBMP-2in vitro. At3,6and9days of the culture, cell morphology was observed by inverted phase-contrast microscopy. In addition, MTT assay and ALP activity test were used to observe the effects of the material on cell differentiation and proliferation.RESULTS:1.Primary osteoblasts were round-like and then became triangular after1-3day culture.Osteoblasts began attach to the dish bottom at2h, Histochemical staining of Alkaline phosphatase demonstrated95%purity of cultured osteoblasts.The mineralized Nodes were studied with alizarin red-5staining.2.MTT/ALP:The osteoblasts response to the material showed that it was considerably cytocompatible."nHAC/rhBMP-2"composite could promote osteoblasts adhesion,proliferation and differentiation.3.Inverted phase-contrast microscopy:Osteoblasts seeded on nHAC/rhBMP-2had good adhesion and proliferative ability.4.Scanning electron microscopy:There were a great of bone-like nodules in High group under electron micros cope.CONCLUSION:Osteoblasts can adhere, grow, differentiate and proliferate better on nHAC/rhBMP-2than allogeneic bone. The composite scaffold nHAC/rhBMP-2has a good compatibility, indicating that the material has a great potential for application in bone tissue engineering.