(466b) Perfluoropolyether (PFPE) Modified Polyurethane Material with Antifouling Surface Properties for Catheter Devices

Catheters are commonly introduced into the vasculature of a patient as part of an intravenous catheter assembly. Polymer materials that have been considered for catheter manufacturing include silicone rubber, Polyethylene (PE), polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP) copolymer, thermoplastic polyurethane (TPU), etc. Among these, TPU is the most commonly used material for peripheral and central venous catheters due to a good balance of physical and mechanical properties (including its softening in vein property) as well as biocompatibility.

After catheter insertion and when blood contacts a foreign material, a complex series of events may occur, which may involve protein deposition, cellular adhesion and aggregation, and activation of blood coagulation schemes. Synthetic plastics including polyurethanes have the potential of being thrombogenic leading to thrombosis-induced catheter occlusions, which may also contribute to catheter-related bloodstream infections (CRBSIs). CRBSIs are caused by the colonization of microorganisms in patients with intravascular catheters and have been linked to thrombus formation.

In this paper, a novel thermoplastic polyurethane composition with perfluoropolyether (PFPE) soft segment was successfully synthesized using a one-step, solvent-less copolymerization process [1]. Only a small amount of PFPE (< 5 wt.%) was introduced into the TPU copolymer, thus the resulting modified TPU shows comparable bulk mechanical properties (including softening ratio in simulated body indwell conditions) as the unmodified TPU. However, a significant surface enrichment of the low surface energy fluoro component was observed in PFPE-modified TPU based on X-Ray Photoelectron Spectroscopy (XPS) surface elemental analysis, and the PFPE-modified TPU presents a more hydrophobic (higher water contact angle) and more lubricious (lower coefficient of friction) surface compared to the unmodified TPU. The novel PFPE-modified TPU material was further extruded into catheter tubing configuration and tested for surface thrombogenicity in an in-vitro Chandler Loop / Blood Loop model using fresh bovine blood. As shown in Figure 1, catheter tubing extruded from PFPE-modified TPU material shows significantly reduced thrombus formation compared to the one extruded from unmodified TPU material, presumably due to the hydrophobic and lubricious surface that can passively reduce attachment of blood components, e.g., protein and fibrin sheath.

The implementation of the above PFPE-modified TPU material in catheter devices can potentially reduce thrombosis-induced catheter occlusions and / or CRBSIs, thus to significantly reduce healthcare costs as well as improve patient experience and clinician confidence.

[1] Self-lubricating medical articles, He Bai and Marc W. Weimer, Becton, Dickinson and Company, US 2020/0093969 A1.