Preparation And Characterization Of Nanofibrous Coating On Artificial Vertebrae

Aim: Bone graft materials are required in the treatment of spinal trauma and tumorous diseases.Nano-hydroxyapatite/polyamide66(n HA/PA66)artificial vertebrae have shown huge potential due to its ideal biocompatibility and mechanical properties.However,the lack of interfacial osteogenesis and antibacterial capabilities limited its clinical application.This research set out to develop nanofibrous coatings with osteogenic,angiogenic and antibacterial properties by electrospinning for the surface modification of n HA/PA66 artificial vertebrae.Methods:(1)Preparation and characterizing of the PLGA nanofibrous coatings loaded with copper and strontium by electrospinning.(2)Biosafety evaluation of the coatings by cell adhesion and proliferation assay.(3)Determine the antibacterial property of the coatings by measuring the adhesion inhibition rate.ALP activity determination,staining,and extracellular matrix mineralization staining experiments were performed to determine the osteogenic induction potential of the coatings;In vitro angiogenesis and cell migration assay were conducted to evaluate the effect of coatings on angiogenesis;we measured the expression level of bone-and vascularformation associated genes and formulated the potential mechanisms.Results:(1)The PLGA,PLGA/Sr,PLGA/Cu,and PLGA/Sr/Cu nanofibers coatings were successfully fabricated with PLGA solution(16%,w/v).The coatings showed porous microstructures and good mechanical properties.Strontium and copper ions were detected to sustainably released from the coatings.(2)The coatings have good biological safety and can well support cell adhesion and proliferation.(3)The copper-loaded coatings can inhibit the adhesion of bacteria;the strontium-loaded coatings can induce osteogenic differentiation by upregulating the expression level of osteogenic genes;the copper-containing coatings improved the angiogenic capability of the endothelial cells by enhancing the expression of angiogenesis-related genes.Conclusion: Electrospun PLGA nanofibrous coatings loaded with strontium and copper were easy to prepare.The excellent antibacterial,osteogenic and proangiogenic properties of the electrospun fibrous coating makes it an ideal surface modification method for n HA/PA66 artificial vertebrae.