Preparation Of Novel Silk Fibroin/Polyurethane Fiber Blend Membrane And Research On Its Properties

Silk fibroin(SF)is one of the most popular raw materials for preparing biomaterials due to its excellent biocompatibility and easy chemical modification.But,in order to avoid the fracture of brittle SF dressings as biomimetic fibers,elastic material polyurethane fiber(PUF)was introduced.In order to enhance the antibacterial properties of SF materials as dressings,the antibacterial drug actinomycin X2(Ac.X2)was immobilized on SF.Finally,the composite biomimetic fiber materials with enhanced antibacterial properties and excellent mechanical properties were obtained.In this paper,pure SF was first blended and modified using PUF.The SF/PUF blend membranes with different mixing ratios were prepared by solution casting method using solution blending.The optimal blend ratio of SF and PUF was found to be50%SF+50%PUF.Secondly,different weight percentages of Ac.X2 were introduced into SF to prepare a new-type SF material containing Ac.X2(ASF).Then,the ASF/PUF blend membranes with the same mixing ratio(50%SF+50%PUF)were prepared using the previous method to explore antibacterial activity and evaluate biosafety.The specific research results were as follows:(1)The SF and PUF were dissolved and mixed with hexafluoroisopropanol(HFIP)to prepare SF/PUF blend membranes with different mixing ratios.The above blend membranes were compared and analyzed using experimental methods such as attenuated total reflectance method(ATR),thermogravimetric analysis(TGA),scanning electron microscopy(SEM),contact angle(CA),dynamic mechanical analysis(DMA),and tensile testing.The results indicated that when SF and PUF were dissolved and mixed,they were only physical blends without any chemical interaction.The 50%SF+50%PUF blend membrane showed a smooth surface and high hydrophilicity(69.2°).The50%SF+50%PUF blend membrane had excellent mechanical properties and flexibility,with a tensile strength of 25.7 MPa and an elongation at break of 946.5%.And the50%SF+50%PUF blend membrane also introduced half of SF,which was conducive to fixing Ac.X2 onto the material through SF.(2)The ASF was obtained by immobilizing different amounts of Ac.X2 onto SF,and the ASF/PUF blend membranes were prepared using the previous method at the same mixing ratio(50%SF+50%PUF).Then,ATR,CA,tensile testing,antibacterial testing,Ac.X2 exudation test,and cytotoxicity test were performed on the ASF/PUF blend membrane.The results showed that the prepared ASF/PUF blend membrane showed high hydrophilicity(68.4°),flexibility,and excellent mechanical properties,with tensile strength and elongation at break exceeding 20.2 MPa and 934.8%,respectively.The ASF/PUF blend membranes showed over 75.0% antibacterial activity against Staphylococcus aureus,and the L929 cells treated with ASF/PUF-0.5 blend membrane showed a cell survival rate of 92.8%.The above experimental results indicates that the ASF/PUF blend membrane has multifunctional properties such as flexibility,excellent mechanical properties,antibacterial activity,and biosafety.The stretchable antibacterial ASF/PUF blend membrane prepared in this research has the potential for application as antibacterial biomimetic fiber.