The Structure And Properties Of Electrospun Silk Fibroin Poly(butylene Succinate) Tubular Scaffold

Now, researchers foucs on using tissue engineering method to build the vascular tissue engineering substitutes. Electrospinning technology could obtain nanoscale diameter fibers.The fibers obtained by electrospinning can provide a biomimetic environment with high surface area and high porosity. So it can be used in tissue engineering extensively. There are many special advantages to develop tissue engineering blood vessels via electrospinning. Because it not only can provide the structure and composition of the extracellular matrix, but also could prepared a tubular structure with a needed diameter by changing the collection of templates of different shapes.Silk fibroin(SF) and poly(butylene succinate)(PBS) were dissolved in HFIP solvents. The SF/PBS composite tubular scaffolds were prepared by electrospinning in this study. Firstly, we studied the effects of the concentrations, voltages, electrospinning distances between syringe and collecting tube on the morphology and structure of the SF/PBS composite fibers. The optimum technical parameters of electrospun SF/PBS composite nanofibers were obtained. Secondly, the effects of ethanol treatment on the structure of composite were investigated by FT-IR and XRD. The water dissolve loss rate of composite fibers was tested. The thermal and the mechanical properties of composite fibers were investigated by TGA and tensile test, respetively. Thirdly, the electrospun SF/PBS composite tubular scaffolds were collected on a 3D collector instead of traditional 2D collector. The effects of 3D collector and process parameters of electrospinning on the morphologies of the tubular scaffolds were investigated. The morphology, structure, porosity, mechanical property and hydrophilicity of the tubular fiber materials were characterized. Finally, the degradation and biocompatibility of the scaffolds were evaluated in vitro degradation experiments and in vitro cell attachment, proliferation tests.The results showed as follows:The optimum technical parameters of electrospun SF/PBS composite nanofibers were set as follows ( listed in the order of concentration, voltage, polar distance and flow rate):6%, 10KV, 15cm, 0.5ml/h. After ethanol treatment, the content of SilkⅡand the crystallinity of SF in the SF/PBS composite nanofibers increased, the water-dissolved rate declined. The addition of PBS can improve the thermal stability and the mechanical properties. The results showed that the SF/PBS composite tubular scaffold has a high porosity, hydrophilicity and excellent mechanical property. Its tensile strength and burst strength have reached the standard of the vascular graft. The results of the vitro degradation showed that the composite fibers had a good biodegradation. In vitro human umbilical vein endothelial cells (HUVECS) cell attachment and proliferation tests showed that the composite scaffold was a good matrix for the growth of cells. Consequently, the SF/PBS composite fiber scaffold may be a potential biomaterial for vascular tissue engineering.