Construction And Properties Of Antibacterial Functional Coatings On Medical Devices

According to the survey results of World Health Organization（WHO）,bacterial infection leads to the failure or shortened lifetime of about 4～6%of medical devices,resulting in tens of millions of patients’suffering and property losses,which mainly because bacteria colonize on the surface of medical devices and then form biofilms.Therefore,it is very important to construct antibacterial surfaces on medical devices.In this dissertation,representative invasive and non-invasive medical devices were selected,and two different antibacterial methods were applied respectively in order to provide effective means for the prevention and treatment of medical device-related infections.In the first part of this paper,Ti was used as the representative invasive medical device for the study of release antibacterial mode.The amino active site was introduced to the surface of inert metal Ti by phase change deposition of egg lysozyme.Then,multi-component antibacterial surfaces with micro-and macro-structures were constructed using the modified hyaluronic acid as the skeleton by Schiff base reaction.Through experimental screening,macro-gel antibacterial coating group（Ti-OGA₅）showed excellent antibacterial performance and good blood compatibility.This macro-gel antibacterial coating is expected to be used in the prevention and treatment of orthopedic implant-related infections.In the second part of this dissertation,gauze was used as the representative non-invasive medical device to study the photothermal antimicrobial effects triggered by white light.The white light responsive photothermal molecule（CR-TPE-T）was modified on the dressing surfaces through hydrophobic interaction.A series of modified dressings(g-CTT₂～g-CTT₁₀)were prepared by changing the concentration of CR-TPE-T.Their physical and chemical properties,biocompatibility,as well as antimicrobial properties were characterized.Finally,the photothermal dressing（g-CTT₈）was screened through experiments as the optimal group.Animal experiments also showed that g-CTT₈ had good anti-infection ability in vivo.This white light responsive broad-spectrum antimicrobial dressing is expected to be applied to the battlefield,field and other harsh environments for effective prevention and treatment of wound infection.In this paper,two representative invasive and non-invasive medical devices were selected:orthopedic implants and medical dressings.According to the different characteristics and application scenarios of the two medical devices,different surface modification methods and strategies were selected to construct antibacterial surfaces.In addition,the biosafety of surface modified medical devices is excellent.This research provides new ideas and strategies for the design and construction of antibacterial surfaces for invasive and non-invasive medical devices.