Hydrophilic And Antibacterial Modifications Of PVC Catheters For Medical Applications

Existing implantable or indwelling catheters are mostly manufactured by hydrophobic polymers,which easily induce non-specific protein adsorption and bacterial colonization during use,resulting in severe bacterial infections,and threatening the public health.Therefore,the development of hydrophilic and antibacterial medical catheters is in urgent demand to tackle this daunting situation.The first part of this thesis,N-vinylpyrrolidone(NVP)was used as a hydrophilic monomer and benzophenone and benzoin dimethyl ether were used as initiators,which were grafted onto the surface of medical polyvinyl chloride(PVC)materials with oxygen plasma treatment by UV light induction to construct medical PVC surfaces with hydrophilic and anti-fouling properties.After the static water contact angle test,the static water contact angle of the hydrophilic functionalized catheter surface was reduced to 15°,and it still did not exceed 20° after ten days of immersion in deionized water,and it could resist the formation of biofilm on the material surface.The hemolysis test and cytotoxicity test both verified that the medical catheter exhibited good biocompatibility for clinical applications.The second part of this thesis,dimethylaminoethyl methacrylate(QDMAEMA)quatemized with bromohexane was selected as the antimicrobial monomer to construct a medical PVC material surface with excellent antimicrobial properties and good biocompatibility.It was experimentally verified that the antimicrobial functionalized PVC materials have a 99%bactericidal rate in a static environment and more than 96%in a circulating flow environment,and they are not cytotoxic and hemolytic.The third part of this thesis,NVP and QDMAEMA were selected as functionalized monomers.After UV-initiated polymerization,the water contact angle of the hydrophilic/bacterial surface decreased to about 20°.After incubation in deionized water for 10 days,the water contact angle was about 30°.Meanwhile,this surface could resist biofilm formation.The results showed that the amount of bacteria on the surface of the material decreased significantly and had excellent bactericidal effect.Moreover,the modified PVC plates exhibited decent biocompatibility for clinical implantable or indwelling applications.Through the research of this thesis,a single hydrophilic and single antimicrobial functionalized surface was achieved on the surface of hydrophobic medical PVC catheter substrate material,and a hydrophilicantimicrobial dual performance surface was successfully constructed for medical PVC catheter material.This study paves a new way for the clinical application of PVC antimicrobial medical catheters.