Abstract
Protein adsorption on materials for medical applications may change their thrombus formation and biocompatibility Zeta potential was determined from data on streaming potential measured on a streaming potential analyzer for three kinds of polymer alloy (polyarylate/polyethersulfone) (PEPA) membranes of varying polymer blend ratios and polacrylonitrile (PAN) membrane before and after cytochrome-C adsorption. Adsorption experiments were also made to determine the time-dependent amount of cytochrome-C adsorbed on the membranes. Intramembrane diffusion coefficient of the PEPA membranes for cytochrome-C was greatly lower than that of the PAN membrane, demonstrating that the PEPA membranes were controlled by adsorption and the PAN membrane by diffusion. The zeta potential of negatively charged membranes such as the PEPA and PAN membranes increased after adsorption of cytochrome-C that behaved like a cation in an aqueous solution of a pH of 6.4. The PAN membrane of higher negative charge gave great changes in zeta potential after cytochrome-C adsorption. In conclusion, adsorption of serum proteins that are ampholytes changes the zeta potential of dialysis membranes and may improve thrombus formation and biocompatibility.
