Amphiphilic PDMS-HEMA membrane surface for improved gas selectivity and blood compatibility

Abstract

While extracorporeal oxygenation (ECMO) is regarded as the golden weapon for patients with cardiopulmonary failure in critical care, its clinical use is usually complicated by the blood coagulation on the hydrophobic surface of the artificial membrane for gas exchange. Herein, amphiphilic polydimethylsiloxane‐hydroxyethyl methacrylate (PDMS-HEMA) material was firstly synthesized from chemical reaction between HEMA and the vinyl group on the side chains of PDMS via a simple process, and then coated on the microporous polyethersulfone (PES) base membrane to obtain PDMS-HEMA/PES composite membrane. Structure characterizations demonstrated that HEMA and PDMS were successfully copolymerized, and PDMS-HEMA/PES composite membranes were well prepared with a flat dense PDMS-HEMA layer coated on the surface of microporous PES substrate. Surface property analyses confirmed much smoother membrane surface, phase-separated morphology, and significant decrement in water contact angles for PDMS-HEMA obtained. More importantly, the PDMS-HEMA/PES composite membrane exhibited a CO2/O2 gas selectivity of ∼6.5 in comparison to ∼5.5 of PDMS/PES, indicating improved gas exchange efficiency. Nevertheless, the PDMS-HEMA/PES composite membrane also displayed excellent and much improved performance in hemocompatibility and long-term stability for storage as well as against blood wetting. Therefore, side-chain modification of hydrophobic PDMS with hydrophilic HEMA through simple chemical copolymerization process is an easy and feasible method to make the membrane surface with long-term amphiphilicity less thrombogenic in contact with blood and more efficient in gas exchanges.