Biocompatible Sulfonated Penta-block Copolymeric Membrane for Hemodialysis

Abstract

Chronic kidney disease is a potential threat for patient’s wellbeing due to high morbidity and imposes a financial burden on the patient. Hemodialysis is the best economical option for end stage renal diseases. The blood is filtered during hemodialysis using a semipermeable membrane and the diffusion principle. Effective removal of uremic toxins can drastically improve the time required and efficiency of the hemodialysis membrane. Therefore, in this work novel interconnected self-assembled membranes are devised to ensure improved separation, better transport, and mechanical strength. NexarTM is an amphiphilic Penta block sulfonated copolymer with rigid end blocks that provides mechanical stability to the membrane. NexarTM can form a long range of self-assembled and ordered nanoscale morphologies that can be altered by the choice of polar or nonpolar solvent. The membrane is cast by using a solution casting method that is economical and easy to handle followed by slow evaporation. Polar solvent form ordered hydrophilic structure of width about 20nm that helps in the clearance of urea and creatinine, while nonpolar solvent offers random hydrophobic arrangement. SEM results show that both the membranes are dense so, the filtration is completely diffusion based. The membranes are tested on dead-end filtration cells for flux measurement and then for hemocompatibility via biocompatibility testing. The experiment reveals that in case of polar solvent the creatinine and urea clearance are increased to 97% and 89.2% respectively, while BSA rejection is 79%. The hemolysis ratio is 3.7%, and the plasma recalcification time is 497 s. In the case of non-polar solvent, the creatinine and urea clearance are 67% and 87.5% respectively and for BSA rejection 72.8%. The biocompatibility results of non-polar solvent shows that the hemolysis ratio is 3.84%, while the plasma recalcification time is 477 s. Comparison of the results shows that the polar solvent is more suitable for hemodialysis as its ordered structure and assembly facilitates the clearance process. The membranes can further be improved by the addition of additives that can enhance the rejection of BSA or facilitate the clearance of urea and creatinine.