Study On The Preparation And Properties Of Regenerated Silk Fibroin/Poly(L-Lactic Acid-Co-ε-Caprolactone) Composite Nanofibrous Membrane Scaffolds

In this study, the ultrafine silk fibroin (SF) which is cross-linked by Genipin fibrousmembranes were prepared by electrospinning. The morphology, structure and mechanicalproperties of the ultrafine fibrous membranes were investigated.It was found that the diameter ofnanofiber became larger, the morphology became nonuniform, the cross-linking dgree wasincreased, the thermal behavior was improved and mechanical properties at ordinarytemperatures with increasing of content of genipin.When the content of genipin is10%, themechanical properties was good, and the breaking stress was19.6MPa, but the breaking strainwas not improved obviously. The ultrafine fibrous scaffolds were non-toxic for L929cell whichwas proved by the experiment of cell cultivation in vitro.To improve the mechanical properties of electropun silk fibroin nanofiber membranes futher,we chose poly(L-lactic acid-co-ε-caprolactone) blend silk fibroin with different mass ratios to fitthe defference of the tissue engineer scaffold. SF/P(LLA-CL) blend composite nanofibrousmembranes was prepared by electrospinning.The result showed that the diameter of nanofiberwas became larger and the morphology became nonuniform with with increasing ofP(LLA-CL).As a result, the thermal behavior of the blend membranes was advanced andmechanical properties was improved. However, the nanofiber membrane was not good for cellcompatibility because of the hydrophobicity of P(LLA-CL).To improve the the mechanical properties of nanofiber membranes and also keep the goodcell compatibility, we prepared SF/P(LLA-CL) shell/core composite nanofiber membranes byco-electrospinning. To improve the mechanical properties of composite membranes futher,MWCNTs was mixed with P(LLA-CL) and discuss the effect of the content of MWCNTs to thethe mechanical properties.The result showed that the thermal behavior was advanced with theincreasing of the content of MWCNTs.When When the content of MWCNTs is1.0%, theMWCNTs disperse uniformly in the P(LLA-CL) and mechanical properties was best.Theblendind of MWCNTs was better for cell compatibility.At last we got the technological parameters of preparing SF/P(LLA-CL) shell/core composite nanofiber membranes best by discussing the affected by core flow rate, core and shellconcentrations. The results revealed that composite nanofibers with uniform morphology andintegrated shell-core structure were obtained when shell and core concentrations were8%and2%respectively and core spinning rates was0.008ml/min. And increase the core concentrationsor core flow rate would improve the mechanical properties.When blending the1.0%MWCNTsto the core, the mechanical properties was advanced futher, the breaking stress was18.7MPa andthe breaking strain was50%.the result of experiment of cell culture showed that SF/P(LLA-CL)shell/core composite nanofiber membranes was good for cell adhere and proliferation.As a result,they have great application potential in tissue engineering scaffolds.