Surface Drag-reducing Modification Of Medical Interventional Catheter Materials

Medical interventional catheters are the most commonly used medical devices in interventional procedures.When catheter insertion is performed,the surface of the catheter will be in direct contact with the human body.The hydrophobicity of the catheter surface can cause protein adsorption and increase the risk of wound infection,while the excessive friction between the catheter surface and human tissue may cause vascular or tissue damage,resulting in pain to the patient.Therefore,medical interventional catheters need to be modified before use to avoid these conditions.In order to solve the above problems,this paper investigates the effect of hydrogenated styrene-butadiene block copolymer(SEBS)as the surface material of interventional catheters,which is modified by melt blending method and hydrogel layer coating method respectively,and investigates the effect of different methods and conditions on the hydrophilicity,anti-protein adhesion performance and drag reduction performance of the material surface.The main research works in this paper are as follows.(1)Internal cross-linked PEG-PVP microgel particles were synthesized using reverse suspension polymerization and introduced into the SEBS system using melt blending method.The hydrophilic,anti-protein adhesion and drag reduction properties of the material surface were better improved.Among them,when the feeding ratio of the prepared microgel monomer PEGMA was 50%and the addition amount of melt blending microgel was 7.5 wt%,the best overall performance of the material was achieved,and the water contact angle decreased from 99.8±1.0°to 78.3±0.4°and the friction coefficient decreased from 0.71±0.08 to 0.27±0.09.(2)Using the principle of interfacial penetration,the PEG-PVP hydrogel layer was coated on the surface of SEBS using UV grafting method,which led to a significant improvement in the hydrophilicity,anti-protein adhesion and drag-reducing lubrication properties of the SEBS surface,and the water contact angle decreased from 99.8±1.0° to 42±0.8°,the friction coefficient decreased from 0.71±0.08 to 0.12±0.04,and the surface fluorescence protein adhesion was significantly reduced.(3)The catheter insertion procedure was simulated using a homemade device,using silicone rubber tubing to simulate the insertion channel and measuring the pulling force required to slide the catheter in it at a uniform speed.The results showed that the pulling force of the SEBS catheter before using the modified catheter was unstable,with peaks of about 2N occurring,and after using the modified catheter,the pulling force leveled off and reduced the insertion force to a minimum of 0.2N.(4)Insoluble particles were tested on the modified material,and the test results conformed to the relevant national standards.