Preparation And Antibacterial Properties Study Of Polylactic Acid Composite Nanofiber Membrane

In recent years,the modification of nanomaterials and their biological applications have attracted more and more attention,and have become a research focus in the field of life analysis.Nanomaterials have been widely used in biomedical fields such as implant materials,tissue engineering scaffolds,blood contact devices and disposable clinical devices.As we all know,the failure of these biomedical devices is usually caused by the adhesion of microorganisms to the surface of the implanted biomaterial to further form a biofilm.The adhesion and growth of bacteria on the surface of the material is considered to be the main cause of biofilm formation.Therefore,it is a technical challenge to prevent microorganisms from adhering to the surface of biomaterials and further developing biofilms on the surface of materials.In view of this,the purpose of this study is to construct a nanofiber membrane with antibacterial function,and it is expected that it can be applied to biological coating materials to achieve antibacterial function to overcome this technical challenge.The specific work content is as follows:1.The functionalization of electrospun membrane with antimicrobial nanomaterials is an attractive strategy when developing functional graphene oxide coating materials to prevent bacterial colonization on surfaces.This research developed a simple approach to produce antimicrobial electrospun membranes by dip-coating a polylactic acid(PLA)nanofiber into a graphene oxide-catechol derivative.PLA was first electrospun to yield narrow-diameter polymeric nanofibers.Then graphene oxide(GO)was modified with catechol derivative-dopamine methacrylamide monomer(DMA)to synthesize GO-DMA nanocomposite material which exhibited robust antimicrobial properties.The catechol can enhance the combination of GO and PLA nanofibers,thereby enhancing the antibacterial properties of GO-DMA.Therefore,the catechol functional group was selected to modify GO in this study.Finally,GO-DMA nanocomposite was impregnated onto PLA nanofiber membrane to prepare GO-DMA functionalized electrospun nanofiber membrane.The research results show that compared with the unmodified PLA nanofiber membrane,GO-DMA modified PLA nanofiber membrane have good hydrophilicity,good biocompatibility and significant ability to inhibit bacterial growth.These results collectively demonstrate the potential of PLA-GO-DMA nanofiber membrane as antimicrobial biomaterials and provide fundamental information toward the establishment of futurebiomedical applications.2.Nanofibrous membranes which exhibit bacteriostatic functions are a good strategy to prevent microorganisms from adhering to the surface of biomaterials.This research report the synthesis of such a nanofibrous membrane which can be applied to biological coatings to realize bacteriostatic functionality.In this study,the polylactic acid(PLA)were mixed with polydopamine-coated Au NPs(Au@PDA NPs)for electrospinning into uniform diameter nanofiber membrane(136.6 nm diameter).Then,the nanofiber membrane is immersed in silver nitrate solution,and the silver ions are directly reduced to silver nanoparticles in situ by utilizing the reducibility of polydopamine to yield PLA-Au@PDA@Ag nanofiber membrane.The PLA-Au@PDA@Ag nanofibers were characterized based on Fourier transform infrared spectroscopy(FT-IR),field emission scanning electron microscopy(FE-SEM),X-ray photoelectron spectroscopy(XPS).The hydrophilicity and stability were studied through the measurement of contact angle,and the anti-biological adhesion ability was studied through the cultivation of different bacteria.The results suggest that the prepared PLA-Au@PDA@Ag nanofiber membrane has good wettability and stability,as well as excellent ability to inhibit bacterial adhesion and growth.The data conclusively illustrates the antimicrobial and biomedical applications of PLA-Au@PDA@Ag nanofibers.