Glycine integrated zwitterionic hemocompatible electrospun poly(ethylene-co-vinyl alcohol) membranes for leukodepletion

This paper describes a novel strategy for the hemocompatibility improvement of poly(ethylene-co-vinyl alcohol) (EVAL) membranes by incorporation of a naturally occurring zwitterion, glycine. Crystalline glycine was directly integrated to the EVAL fibers via electrospinning. The membranes were characterized by Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), Water Contact Angle measurements (WCA) and measurement of Critical Wetting Surface Tension (CWST). The impact of glycine integration on the membrane parameters was assessed by variations in fiber diameter, pore size and percentage porosity. The release of glycine from the membranes was also quantitatively evaluated by ninhydrin assay. The interplay of zwitterion structural features on the blood compatibility was studied by in vitro hemocompatibility evaluation and blood filtration studies. The outcomes of these investigations highlight that glycine incorporated membranes offer greater hemocompatibility than virgin EVAL membranes in terms of reduced hemolysis, increased RBC retention, decreased adhesion and activation of platelets. The type of membrane modification can be considered in future for the development of leukodepletion filter membranes.