Hemocompatible poly(lactic acid) membranes prepared by immobilizing carboxylated graphene oxide via mussel-inspired method for hemodialysis

Poly(lactic acid) (PLA) is an environmentally friendly material, but the hydrophobicity and poor hemocompatibility of PLA impede its application as hemodialysis membranes. In this study, aiming to improve the hemocompatibility of PLA membranes, dopamine-g-carboxylated graphene oxide (DA-g-GOCOOH) was synthesized and then immobilized on PLA membranes via a mussel-inspired adhesion method. The effect of carboxyl content of graphene oxide on hemocompatibility was also investigated. Attenuated total reflectance Fourier transform infrared spectra (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis confirmed that DA-g-GOCOOH was successfully immobilized on the PLA membranes. The significant improvement of hydrophilicity and electronegativity of the PLA membranes effectively alleviated the surface adhesion of platelets, prolonged the recalcification time and reduced the hemolysis ratio to less than 0.3%. Moreover, the DA-g-GOCOOH modified PLA membrane showed excellent dialysis performance, especially for the clearance of middle molecule toxin, which was up to 24%. The DA-g-GOCOOH immobilized layers were relatively stable after incubating in water. The present work demonstrated a potential way to improve the hemocompatibility of PLA membranes for hemodialysis.