Preparation And Performance Study Of Anti-infection Functional Silicone Rubber Medical Catheter Coating

With the emergence of implantation/interventional medical devices that are widely used in clinical practice.The various types of nosocomial infections caused by them are common problems faced by hospitals around the world,especially the use of a large number of medical catheters,whether it is the thrombosis problem caused by the use of catheters,or the catheter-related fiber sheath wrapping problem,will cause different degrees of infection Therefore,the infection problem caused by medical catheters is still the focus of clinicians'attention,and it is an urgent problem to be solved in the use of medical catheters.This article focuses on the infection caused by medical catheters.The researchers focused their research on anti-infective functional coatings,such as drug-loaded coatings,inorganic antibacterial agent coatings,organic antibacterial agent coatings,and so on.Among them,medical catheters with nano-silver coatings and antibiotic-bearing coatings have been used clinically.However,the biological safety of nano silver and the drug resistance caused by long-term use of antibiotics are the urgent problems to be solved in the current anti-infection catheters.In this thesis,the element copper has antibacterial and anticoagulant functions,and a polymer-containing copper?chitosan/copper?coating with anti-infection function is prepared on the surface of the medical catheter by chemical grafting method to develop a kind of anti-infection function.A new generation of medical catheters.X-ray photoelectron spectroscopy?XPS?,contact angle?CA?,Fourier infrared spectroscopy?FTIR?,scanning electron microscope?SEM?and other test methods to characterize the functional coating;at the same time through in vitro antibacterial experiments on the coating The antibacterial functionality of the layer is evaluated;and the biological safety of the coating is evaluated by cell experiments.On the premise of verifying the functionality and biological safety of the chitosan/copper functionalized coating,chemical bonding is used to ensure the effective combination of the functional coating and the catheter.The main research contents and corresponding conclusions of this thesis are as follows:?1?Surface activation pretreatment of medical silicone rubber catheterTwo ways are used to strengthen the effective combination of coating and substrate.Method 1:Chemical cross-linking method introduces active functional groups on the surface of silicone rubber catheter.In the first step,dopamine is used to activate the surface of the silicone rubber catheter,and active groups such as amine groups and hydroxyl groups are successfully introduced.In the second step,aldehyde groups are introduced through glutaraldehyde crosslinking.X-ray photoelectron spectroscopy was used to detect the surface of the sample after each step of treatment,and the chemical bonding method between the pretreatment coating and the silicone rubber matrix was analyzed.Method 2:Plasma activation treatment.Through O₂ plasma treatment,the introduction of hydroxyl reactive groups,while improving the surface roughness of silicone rubber.The surface properties of the pretreated silicone rubber were analyzed by a contact angle tester and a surface profiler.The results showed that after pretreatment with O2 plasma,the surface of the silicone rubber was enhanced in hydrophilicity and roughness.?2?Preparation and characterization of chitosan/copper?CS/Cu?coating.Using-NH₂ and-OH active groups on chitosan to bond copper ions to chelate copper ions with chitosan,it is formulated into a coating solution,and the functionalized solution is prepared in the pretreated by the pull method Hang on the silicone rubber sample by hanging.In this thesis,the properties of the coating are characterized by means of FTIR,XPS,SEM,surface tension,etc.The results show that:coatings prepared on different pretreated silicone rubber surfaces have obvious differences in coating surface morphology and are chemically activated by polydopamine After that,the surface of the coating is uniform and stable;the surface of the coating prepared after O₂ plasma treatment is even and flat.Through infrared spectroscopy and X-ray photoelectron spectroscopy,the copper ions in the coating were bonded to-NH2 and-OH on the chitosan through coordination bonds.At the same time,through the detection of the contact angle of the coating surface,the contact angle of double distilled water and bromonaphthalene on the copper-containing coating is greater than that of the unbonded copper ion coating.After calculation,the chitosan coating and the copper-containing coating surface The tension is similar.After grafting copper ions,the dispersion force increases and the polar force decreases.?3?Research on antibacterial properties of CS/Cu coatingThrough an in vitro antibacterial experiment,the instant antibacterial function and antibacterial durability of the chitosan/copper coating were evaluated.The results showed that the addition of copper ions greatly improved the antibacterial performance of the chitosan coating,and the antibacterial rate was as high as 95%.The copper ion dissolution experiment shows that the antibacterial effect of the CS/Cu coating is caused by the continuous dissolution of copper ions,thereby playing an antibacterial effect.And through the evaluation of the contact between the coatings immersed in different times and bacteria,the coatings soaked for 28days still have high-efficiency antibacterial properties,and the antibacterial rate reaches more than 90%.?5?Research on the biological safety of CS/Cu coatingThrough an in vitro cytotoxicity test,the biosafety of CS/Cu coating was evaluated.The results showed that the copper-containing coating was not biotoxic to the cells and fully complied with the biological requirements of medical catheters,providing a strong basis for its clinical application.To sum up,this thesis developed a copper-containing functional medical catheter,research confirmed that it has high-efficiency antibacterial function,speculation that it can fully exert its prevention and resistance to bacterial infections in the future.As a medical catheter coating material,it has good application prospects.