The Lubrication And Antibacterial Function Of Medical Cathether Based On Cation Antibacterial Agent

Catheter-associated urinary tract infections(CAUTIs)are the most common hospital-associated infections and pose a significant risk to the physical and mental health of patients.The hydrophobic nature of the catheter material also causes additional mechanical damage to the patient and tissue damage during insertion,so it is important to construct an antimicrobial lubricant coating for the surface of the catheter material.To address these issues,this thesis constructs a non-pharmaceutical polyurethane coating solution based on cationic antimicrobial agents with both antimicrobial and lubricating functions,with the aim of reducing catheter-related infections and avoiding damage to the urethra caused by friction through surface coating.Firstly,this paper successfully synthesized three polyhydroxy cationic polymers with different carbon chain lengths,QMDEA-C12,QMDEA-C10,and QMDEA-C6.A binary alcohol based antibacterial lubrication coating was designed,and coating formulations with different hydroxyl ratios were designed using the reaction between hydroxyl groups and isocyanates.After experimental screening,the antibacterial agent QMDEA-C10 had good antibacterial activity.The prepared coating was successfully modified on the surface of polyurethane substrate,and had good antibacterial effect(over 99%)against both negative and positive bacteria,while also exhibiting significant hydrophilic lubrication effect.However,it was found that the coating was not firm(the hydrophilic angle gradually increased in ten friction tests),and the lubrication performance was not durable(the relative friction coefficient gradually increased in ten friction tests).Therefore,in order to solve this problem,an antibacterial lubrication coating based on ternary alcohol was designed.In the construction of this coating,this paper strives to find a balance between high antibacterial activity and biosafety by exploring certain process conditions,and further verifies the coating’s resistance to sensitive bacteria,non sensitive bacteria,and biofilm,while proving its non release bactericidal properties.Further screening of the optimal coating PU-C10-46 group was conducted to explore the antibacterial mechanism of the coating.After soaking in urine for 14 days,the antibacterial rate of the coating against Staphylococcus aureus can still reach over 99%.The coating obtained through in vitro experiments still has good antibacterial effects after being applied in vivo.The antibacterial rate of both the one day and three day groups implanted in vivo can reach over 80%,and the coating has a certain degree of biological safety,no substantial damage was caused to the main organs.The performance of this coating has also been verified in industrial experiments,and the antibacterial rate of several formulations of coatings can reach over 99%,with good biological safety(cell compatibility can reach over 70%),and significant lubrication performance(friction coefficient reduction of over 80%).This non release coating can provide some exploratory work for constructing antibacterial lubrication modification on the surface of medical devices.This article aims to construct a non drug sustained-release coating on the surface of polyurethane to achieve antibacterial,anti biofilm,hydrophilic lubrication and other properties of the coating.It is expected to alleviate the urinary tract infection related to catheter in the sense of materials on the premise of giving consideration to biological safety,having certain antibacterial efficacy,facing clinical needs,and combining production conditions.