Hemocompatible polydimethylsiloxane/polysulfone ultrathin composite membrane for extracorporeal membrane oxygenation

Abstract

Although dense polydimethylsiloxane (PDMS) membranes, the first membranes used for extracorporeal membrane oxygenation (ECMO) system, exhibited biological inertness with no plasma leakage or air embolism occurred during oxygenation process, they also displayed low CO2/O2 exchange capacities due to the large membrane thickness making up for the low material mechanical strength. Herein, polydimethylsiloxane/polysulfone (PDMS/PSF) composite membranes were firstly synthesized with an ultra-thin PDMS dense layer coated on PSF porous substrate of excellent mechanical strength, then characterized by SEM, EDS, TGA, zeta potential and static contact angle measurements for structural and surface property analyses, and further evaluated for their CO2/O2 permeation and hemocompatibility performances as well as the influence of sterilization on the properties. Characterization results showed that an ultra-thin PDMS dense layer were successfully coated on PSF substrate and the composite membranes obtained demonstrated thermostability, surface electronegativity and hydrophobicity. Gas permeation analyses indicated that the composite membranes exhibited efficient CO2/O2 exchange capacity with an optimum CO2 permeability of ∼ 2700GPU at atmospheric pressure and a CO2/O2 selectivity of ∼ 6. Moreover, hemocompatibility analyses demonstrated that the PDMS/PSF composite membranes in current work displayed comparable blood compatibility to other membranes investigated. Meanwhile, autoclave was proved feasible for membrane sterilization with no adverse effects on the performances of PDMS/PSF composite membranes. These findings suggested that PDMS/PSF composite membranes showed great application potential in ECMO system, and provided basic data for further exploration and modifications.