Fabrication of Zwitterion TiO2 Nanomaterial-Based Nanocomposite Membranes for Improved Antifouling and Antibacterial Properties and Hemocompatibility and Reduced Cytotoxicity

Abstract

Although zwitterion nanomaterials exhibit outstanding antifouling property, hemocompatibility, and antibacterial activity, their poor solubility in organic solvents limits their practical applications. In the present study, natural lysine (amino acids) was surface-grafted onto one-dimensional (1D) TiO2 nanofibers (NFs) through an epoxy ring opening in which the 3-glycidyloxypropyl (dimethoxy) methyl silane was used as a coupling agent. Chemical binding and morphological studies, such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy, were conducted to confirm the successful grafting of lysine onto the TiO2 NFs. The lysine-grafted TiO2 NF-polyethersulfone (PES) membrane induced electrostatic interactions and increased the surface charges from -28 to 16 mV in ζ-potential analysis. The lysine exhibited zwitterion characteristics owing to the presence of amino (cations) and carboxyl (anions) functional groups. Moreover, the modified TiO2-PES zwitterion membranes exhibited good water flux performances compared to the pristine membrane. ZT-4 membrane displayed the highest water fluxand bovine serum albumin (BSA) rejection of 137 ± 1.8 L m-2 h-1 and 94 ± 1%, respectively. The cell viability results revealed that the zwitterion PES membrane had excellent biocompatibility with peripheral blood mononuclear cells. The present work offers a convenient strategy to improve the hydrophilicity, antifouling property, and hemocompatibility of modified TiO2-PES zwitterion membranes for their biomedical and blood-contacting applications such as hemodialysis.