Osteogenesis Of BMP-2/IGF-1-SF/P(LLA-CL) Coaxial Electrospun Barrier Membrane

Objective: To construct nanofiber barrier membrane carried bone morphogenetic protein-2(BMP-2)and insulin-like growth factor-1(IGF-1)by using of the coaxial electrospinning technique.In vitro nanofiber barrier films were used to study the effect of carrying growth factors on osteogenic differentiation of stem cells,and their effects on the repairing of skull defects in SD rats were studied in vivo.Methods:(1)Utilizing the parameters of 15 kV high voltage,15 cm working distance,the flow rate of the core liquid is 1mL/h;the flow rate of the shell liquid is 10 mL/h,to prepare the coaxial electrospun nanofiber barrier membrane.(2)In vitro experiments: BMSCs of the SD rats were isolated and cultivated.Cells and materials were co-cultivated to observe the adhesion of cells on the membrane;MTT was used to detect the growth condition of the cell on the membrane;ALP detection and the alizarin red staining were performed to evaluate the ability of fibrous membrane to promote stem cells osteoblast differentiation in vitro;Q-PCR was used to detect the expression of the osteogenic gene.(3)In vivo experiment: 50 SD rats were divided into five groups: drug-loaded group: BMP-2/IGF-1-SF/P(LLA-CL),BMP-2-SF/P(LLA-CL),IGF-1-SF/P(LLA-CL),non-drug-loaded group : SF/P(LLA-CL),blank control group,8mm bone defect was made of rat skull bone then implantated the materials in rat skull defect area.After 4 weeks,8 weeks and 12 weeks of feeding,micro-CT examination and histological examination were performed on isolated skull tissues.RESULTS:(1)The coaxial electrospinning of the core layer carrying growth factor was successfully prepared;(2)The vitro experiments showed that BMSCs adhered well to the nanofiber membrane,and the MTT assay showed that cells grow well on the membrane,Alkaline phosphates activity was increased in the group loading drug,and calcium nodules were formed by alizarin red staining.(3)The vivo experiments showed that the growth condition of the animals was good after operation.The volume of new bone was detected by micro-CT.There was significant difference between the experimental group and the control group(P<0.05).HE staining showed the area of new bone tissue in the experimental group greater than the control group.Conclusion: The BMP-2/IGF-1-SF/P(LLA-CL)nanofiber barrier membrane could carry biologically active growth factor in the core.The fibrous membrane has the function of inducing bone tissue regeneration.It can be expected to be used as a barrier membrane in clinical bone augmentation surgery.