Preparation and characterisation of biocompatible polyethersulfone-based hollow fibre membrane for haemodialysis application

In Malaysia, the number of dialysis patient keeps increasing every year with an estimation of 5,000 new cases of end-stage kidney failure (ESRD) each year. Thus, the development of an efficient haemodialyser is crucial to meet this demand. The objective of this research is to develop a biocompatible asymmetric, ultrafiltration hollow fibre membrane (HFM) for haemodialysis application. Polyethersulfone (PES) was chosen as the main polymer in the fabrication of the haemodialysis HFM due to its outstanding oxidative, thermal and hydrolytic stability as well as good mechanical and film-forming properties. Polyurethane (PU) heparin like structure (range of 0-5wt%) was used as additive in the PES HFM to improve blood compatibility of PES HFM. The HFM of blended PES/PU was fabricated using a dry/wet inversion phase spinning technique and its properties was characterised using a number of physico-chemical analyses and in-vitro blood compatibility tests. For the physico-chemical analyses, each of the membrane fabricated showed the desired asymmetry structure, dense area in the inner surface near the lumen and finger-like structure near the end of the outer membrane. The pore size of the membrane is in good agreement with the morphology and the surface roughness of the membrane. A high amount of PU in the membrane resulted in more porous finger-like pore structure, smoother surface, higher hydrophilicity and higher pore size. Based on the in-vitro biocompatibility analysis of the membrane, it is proposed that the membrane incorporated with PU has better anticoagulant properties compared to the control sample. PU incorporation prolonged the clotting time, decreased the formation of thrombin, decreased soluble C3a generation and suppressed platelet adhesion and aggregation. The anionic groups on the membrane surface might bind to coagulation factors (antithrombin) and thus improve anticoagulant ability. Based on both physico-chemical and in-vitro results, 4% loading of PU is the optimum loading for incorporation with PES HFM. The results suggested that the blended PES-PU membranes with good haemocompatibility should be applied in the field of blood purification during haemodialysis process