Thromboresistance of Polyurethanes Modified with PEO‐Silane Amphiphiles

Abstract

Surface‐induced thrombosis is problematic in blood‐contacting devices composed of silicones or polyurethanes (PUs). Poly(ethylene oxide)‐silane amphiphiles (PEO‐SA) are previously shown effective as surface modifying additives (SMAs) in silicones for enhanced thromboresistance. This study investigates PEO‐SAs as SMAs in a PU at various concentrations: 5, 10, 25, 50, and 100 µmol g−1 PU. PEO‐SA modified PUs are evaluated for their mechanical properties, water‐driven surface restructuring, and adhesion resistance against a human fibrinogen (HF) solution as well as whole human blood. Stability is assessed by monitoring hydrophilicity, water uptake, and mass loss following air‐ or aqueous‐conditioning. PEO‐SA modified PUs do not demonstrate plasticization, as evidenced by minimal changes in glass transition temperature, modulus, tensile strength, and percent strain at break. These also show a concentration‐dependent increase in hydrophilicity that is sustained following air‐ and aqueous‐conditioning for concentrations ≥25 µmol g−1. Additionally, water uptake and mass loss are minimal at all concentrations. Although protein resistance is not enhanced versus an HF solution, PEO‐SA modified PUs have significantly reduced protein adsorption and platelet adhesion from human blood at concentrations ≥10 µmol g−1. Overall, this study demonstrates the versatility of PEO‐SAs as SMAs in PU, which leads to enhanced and sustained hydrophilicity as well as thromboresistance.