Biocompatibility of a polymer-coated membrane possessing a hydrophilic blood-contacting layer: Adsorption-related assessment

Abstract

Objective:

Currently, the foreign surfaces of extracorporeal circulation devices are coated with an acrylate-based copolymer that creates a hydrophilic blood-contacting layer to enhance biocompatibility. Several reports of acrylate-based copolymer with respect to biocompatibility have been published; however, the adsorption of peptide compounds on acrylate-based copolymer–coated membranes still requires clarity. In this study, we aimed to understand the adsorption of several peptide compounds of various molecular weights, including albumin, lysozyme, and vancomycin, on acrylate-based copolymer–coated membranes using in vitro studies.

Methods:

Six experimental circuits consisting of acrylate-based copolymer–coated tubes and membranes, and six comprising acrylate-based copolymer–coated tubes and non-coated membranes were prepared for comparison. An experimental solution, composed of albumin, lysozyme, vancomycin, and saline, was continuously stirred in a reservoir, recirculated in each experimental circuit, and then filtered. Concentrations of albumin, lysozyme, and vancomycin were measured after 0, 15, 30, 45, 60, 90, and 120 min of recirculation. Similar experiments were performed in all the prepared circuits.

Results:

The ratio of measured values at each time point to those at 0 min was not significantly different between acrylate-based copolymer–coated and non-coated membranes for albumin and lysozyme, but differed significantly for vancomycin; the ratios were higher in acrylate-based copolymer–coated than in non-coated membranes.

Conclusion:

This study suggests that albumin is not adsorbed on either acrylate-based copolymer–coated or non-coated membranes, that lysozyme is not adsorbed on either membrane or is adsorbed at a similar rate on both membranes, and that vancomycin is less adsorbed on acrylate-based copolymer–coated membranes. Thus, acrylate-based copolymer coating could inhibit the adsorption of various peptide compounds.