Biomimetic surface modification on polyacrylonitrile-based asymmetric membranes via direct formation of phospholipid moieties

To improve the antifouling property and biocompatibility for polyacrylonitrile-based asymmetric membranes, phospholipid moieties were directly anchored on the poly(acrylonitrile-co-2-hydroxyethyl methacrylate) (PANCHEMA) membrane surface through the reaction of hydroxyl groups and 2-chloro-2-oxo-1,3,2-dioxaphospholane (COP) followed by the ring-opening of COP with trimethylamine. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and water contact angle measurement were employed to confirm the conducted surface modification. Water and protein solution filtration tests plus cell adhesion measurement were used to evaluate the antifouling property and the biocompatibility of the membranes. It was found that the content of the phospholipid moieties on the membrane surface, which can be mainly modulated by the content of reactive hydroxyl groups in PANCHEMA, has a great influence on the performances of the studied membranes. With the increase in the phospholipid moieties content at the modified membrane surface, the hydrophilicity and biocompatibility on the basis of water contact angle and macrophage adhesion can be improved significantly. Furthermore, the modified membranes show higher water and protein solution fluxes, and better flux recovery after cleaning than those of the original PANCHEMA membranes. All these results reveal that the antifouling property and biocompatibility of PANCHEMA membrane could be enhanced obviously by the introduction of phospholipid moieties on the membrane surface.