Zwitterionic sulfobetaine-modified non-woven fabric for blood filtration

Blood filtration requires a high removal ratio of leukocytes and with simultaneous high recovery ratio of platelets and other beneficial components. Problems are often encountered with blood filter materials in terms of high platelet loss. Zwitterions such as phosphorylcholine, sulfobetaine and carboxybetaine show effective resistance against protein adsorption and platelet adhesion. The study reported was aimed at achieving surface modification of poly(butylene terephthalate) non-woven fabric (PBTNF) using UV radiation-induced graft copolymerization of a zwitterionic sulfobetaine, N-(3-sulfopropyl)-N-methacroyloxyethyl-N, N-dimethylammonium betaine (SMDB), in order to improve the wettability and platelet recovery ratio of the PBTNF. Attenuated total reflection Fourier transform infrared and X-ray photoelectron spectroscopy results showed that SMDB was successfully grafted onto the PBTNF. Photoinitiator concentration, monomer concentration and UV irradiation time affected markedly the degree of grafting. Critical wetting surface tension, water wetting time and hemolysis tests showed an improvement in wettability and blood compatibility as a result of graft copolymerization of SMDB. A blood filter material composed of SMDB-modified PBTNF reduced platelet adhesion and had higher platelet recovery compared to poly(acrylic acid)-modified PBTNF. It was found that SMDB monomer was successfully grafted onto PBTNF using UV radiation. The degree of grafting of SMDB could be controlled by varying the photoinitiator concentration, monomer concentration and UV irradiation time. SMDB-modified PBTNF showed significant improvement in wettability and blood compatibility. The zwitterionic structure of SMDB is resistant to platelet adhesion. The SMDB-modified PBTNF could be a candidate for a blood filter material and in other medical applications. (C) 2010 Society of Chemical Industry