Reinforced Concrete Inspired Bioglass-cement/magnesium-alloy Composite Scaffolds With Cortical Bone-matching Mechanical Properties Promote Load-baring Bone Regeneration

Various therapeutic platforms have been developed for repairing bone defects.However,load-bearing bone defects repair is still challenging in the clinic.In this study,inspired by the structure of the ferroconcrete,a high-strength bifunctional scaffold has been developed by combining surface-modified magnesium alloy as the internal load-bearing skeleton and bioglass-magnesium phosphate bone cement as the osteoinductive matrix.The scaffold combines the high mechanical strength and controllable biodegradability of surface-modified magnesium alloy with the excellent biocompatibility and osteoinductivity of bioglass-magnesium phosphate bone cement,thus providing support for load-bearing bone defects and subsequently bone regeneration.The scaffolds generate hydroxyapatite(HA)during the degrading procedure in simulated body fluid(SBF)with the strength of the scaffold decreasing slowly,but still sufficient for load-bearing bone.The scaffolds promote osteoblast differentiation of bone marrow mesenchymal stem cells(BMSCs)in vitro.In a New Zealand White Rabbit radius defect model,the scaffolds degrade gradually and are replaced by highly matured new bone tissues,as assessed by Imagological analyses(X-ray and Micro-CT)and histological analyses.The scaffold can be applied to provide support for load-bearing bone defects and accelerate bone tissue growth.