Hydrophobic Initiator Activates the Interface Reaction to Trigger Polymerization Graft Polytetrafluoroethylene Catheter

Decreasing the surface friction coefficient of medical catheters is important especially in interventional treatment, but the current solution involves high cost or cumbersome manufacturing processes. In order to effectively solve the problem of high friction coefficient of the inner and outer layers in the use of medical catheters and simplify the manufacturing process, we use polytetrafluoroethylene (PTFE) as a catheter material to graft directly with PAAm hydrogel. In order to overcome the high chemical inertness and low surface energy of PTFE, nitrogen ion injection is used to modify the surface of PTFE. The resulting porous PTFE surface is loaded with initiators and the hydrogel monomers polymerize in situ to form a lubricating layer. The hydrogel coating is strongly bonding on PTFE substrate, the maximum 180° peel strength between PAAm hydrogel and PTFE substrate reaches at 222 N/m. The hydrogel lubricating layer provide a friction coefficient of 0.04. In addition, in comparison to silicone rubber, the surface biofilm adhesion is diminished by 350%, demonstrating exceptional anti-fouling characteristics. This study provides a new idea and method for the surface low friction design of implantable medical devices.