Abstract: Objective To construct a composite scaffold with osteoconductivity and osteoinductivity by biomineralization,and to conduct a guided bone regeneration study on the critical calvaria defect of rats.Methods The collagen scaffolds were fabricated out of the swine typeⅠcollagen by electrospinning and immersed in simulated body fluid(SBF),then the inorganic components of SBF were deposited in collagen scaffold by biomineralization.After scanning electron microscope observation and physical and chemical properties test,rat bone marrow mesenchymal stem cells were seeded on the scaffold material of biological collagen before and after mineralization as premineralization group and postmineralization group,blank control group was also set up.The biotoxicity was detected by Live/Dead staining,and the biocompatibility and biodegradability were tested after subcutaneous implantation into rat's dorsum.PCR,Western-blot,ALP and ARS staining were used to detect the effects on osteogenic differentiation of mesenchymal stem cells in vitro.The osteoconductivity and osteoinductivity of mineralized collagen scaffold in vivo was tested in rat craniofacial defect model.Results After 4 weeks of mineralization,the mineralized particles increased obviously.According to the results of TGA and ICP,the inorganic substances,especially the amounts of calcium and phosphorus were increased.The biotoxicity test and the results of subcutaneous implantation showed good biocompatibility and biodegradability of the material.The results of PCR,Western blot,ALP and ARS staining revealed similar results,the ability of collagen electrospinning after mineralization was superior to that of premineralization group and the blank control group.In the calvaria defect repair test of rats,the new bone formation area,the percent bone volume(bone volume/tissue volume,BV/TV),bone surface density(bone surface/tissue volume,BS/TV),the number of trabecular(Tb.N),bone mineral density(BMD),the new bone formation area of mineralized collagen reconstructed calvaria were

Key words: Collagen electrospinning, Biomineralization, Bone defect, Bone regeneration