No abstract

The antifouling properties of poly­(ethylene oxide) (PEO)-silane amphiphiles as surface-modifying additives (SMAs) in a condensation cure silicone have been previously demonstrated against simple protein solutions. Comprising an oligo­(dimethylsiloxane) tether (m = 13 or 30) and PEO segment (n = 8), sustained protein resistance was achieved even in the absence of a cross-linkable triethoxysilane group, particularly when comprising the longer tether. To probe their potential for thromboresistance, PEO-silane amphiphile SMAs were used to bulk-modify silicones and evaluated for adhesion resistance against whole human blood under both static and dynamic conditions. Both a cross-linkable (XL diblock, m = 13) and a non-cross-linkable (Diblock, m = 30) SMA were evaluated at various concentrations (5–50 μmol SMA/g silicone) in a condensation cure silicone. Under static conditions, silicones modified with either SMA at concentrations of 10 μmol/g or greater were effective in reducing adhesion of human fibrinogen and platelets. Dynamic testing further showed that modified silicones were able to reduce protein adsorption and thrombus formation. This occurred at 5 and 10 μmol/g for silicones modified with XL diblock, m = 13 and Diblock, m = 30 SMAs, respectively. Combined, these results indicate the effectiveness of PEO-silane amphiphiles as SMAs in silicone for improved thromboresistance.

Oil palm nanocellulose has been demonstrated to display a wide range of unique properties for many fields. They are suitable for biomedical applications and have been used in this domain for decades. The current variety of nanocellulose fibers allows the development of new nanocomposites. This work fabricated oil palm nanocellulose with variations of fiber loading (1, 2, 3, 4, and 5 wt%) and thermoplastic polyurethane (TPU) polymer matrix by using a mechanical stirring followed by hot pressing methods. The physical characters of nanocellulose oil palm reinforced TPU nanocomposites, such as water absorption, thickness swelling, and density were characterized. The fiber loading of oil palm nanocellulose content at 5 wt% shows the highest water uptake, thickness swelling, and the lowest density properties of oil palm nanocellulose reinforced TPU nanocomposites.

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.