Dextran sulfate bulk and surface-modified microfiltration membrane for simultaneous blood plasma harvesting and low-density lipoprotein removal during plasmapheresis

Abstract

Plasmapheresis is currently used for the harvesting of blood plasma in medical labs and plasma donation centers. This is a fast, single-step membrane process for both collection of blood plasma and simultaneous blood cell isolation. This paper presents the development of a novel membrane that can be used to simultaneously harvest blood plasma and isolate low-density lipoprotein (LDL), known as bad cholesterol, from the blood. To achieve this goal, dual surface and bulk modification by dextran sulfate (DS) was performed on a polyethersulfone (PES) membrane containing single wall carbon nanotubes (SWCNT). DS is an anionic ligand that repels negatively charged substances like red blood cells (RBCs) and adsorbs positively charged substances like Apo B100; the apoprotein of LDL. Scanning Electron Microscope (SEM), Energy Dispersive X-Ray (EDX), and Fourier Transform Infrared (FTIR) spectroscopy analyses provided evidence of the grafting of DS on single wall carbon nanotubes (DS-SWCNT). Surface studies including water contact angle, zeta potential analysis, surface morphology, Attenuated Total Reflectance-FTIR (ATR-FTIR), and EDX, confirmed the presence of DS on the PES membrane surface. The SEM cross-section results showed the formation of a two-zone morphology with an open structure on the upside and a dense structure on the downside that provide optimal conditions for efficient separation of blood cells. The complete blood count (CBC) and biochemistry analyses revealed dual bulk and surface-modified membrane, and a specific sample (DM2) showed the best performance for blood cells and LDL separation. The maximum separation of blood cells was 87% RBC, 98% white blood cells (WBCs), and 83% platelets (PLTs). Moreover, DM2 exhibited a sieving ratio for LDL of 0.33. Blood compatibility analyses confirmed that DM2 and other related samples had low hemolysis and prolonged coagulation times.