A low-friction and high-stability hydrophilic PVP/PEG coated TPU for interventional catheter applications

Vascular interventional catheters are generally made of hydrophobic polymers, which may lead to vascular injury, poor lubrication and other consequences due to friction with vascular wall or stent in the process of intervention. In this study, the PDA-PVP/PEG composite coating was prepared based on common TPU catheter material to improve its hydrophilic lubrication behavior. Firstly, the oxidative self-polymerization of dopamine (PDA) was initiated and deposited on the surface of TPU in a weak alkali environment, and then the PVP/PEG coating was prepared by UV curing with PDA as the intermediate adhesion layer. The composite coating was optimized step by step by lubricating material system, process parameters, molecular weight, and concentration. Compared with the blank control group, the water contact angle decreased from 91.3° to about 28.3°, and the friction coefficient decreased from 0.4 to about 0.03, and the composite coating was not damaged after 30 min of reciprocating sliding. The results of cytotoxicity grade Level 1 and hemolysis rate less than 5 % also proved that the composite coating showed good cytotoxicity and blood compatibility. In summary, the PDA-PVP/PEG hydrophilic lubricating composite coating revealed excellent comprehensive properties.