Developing blood leukocytes depletion membranes from the design of bio-inert PEGylated hydrogel interfaces with surface charge control

Abstract

This study investigates the development of membranes for leukocytes depletion from model hydrogel interfaces. We first designed hydrogels from 2-(dimethylamino)ethyl methacrylate (DMAEMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) to form poly(DMAEMA-co-PEGMA), and [2-(methacryloyloxy)ethyl]trimethylammonium chloride (TMA) and PEGMA to form poly(TMA-co-PEGMA). After characterizing the actual chemical composition of the hydrogels by XPS, efforts were made on studying the effect of the nature and content of amine functional group on the hydrophilicity and the surface charge of the gels. The adhesion of fibrinogen and blood cells was then methodically studied. Both types of gel are positively charged at pH 7.4, promoting fibrinogen and cell attachment. However, for the particular composition of 64% of DMAEMA in the hydrogel, results reveal that the adhesion of leukocytes was more important than that of erythrocytes and thrombocytes, thus suggesting that the control of the surface charge could lead to the selective adhesion of leukocytes. Based on these results, membranes were developed and tested in blood filtration for leukocyte depletion. Results prove that polypropylene membranes modified with a poly(DMAEMA-co-PEGMA) layer, containing 64% of DMAEMA can effectively lead to leukocyte depletion during blood filtration (99.6%) still maintaining a high erythrocytes recovery (98%).