MECHANISM OF ADSORPTION OF HUMAN ALBUMIN TO TITANIUM IN-VITRO

Our previous studies have shown that human albumin is one of the main salivary proteins that adsorb to titanium (Ti). The goal of the presen t study was to investigate the role of electrostatic interactions in t he adsorption of human albumin to Ti-oxide (TiO2) in vitro. The bindin g profile of human albumin to Ti was analyzed according to an adsorpti on isotherm. Purified human serum albumin (HSA) was suspended with nat ive, calcium-, magnesium-, or potassium-treated commercially pure Ti p owders, at pH 3.0 and 7.0. The amount of unadsorbed protein in the sup ernatant fluid was measured. The maximum amount of adsorbed albumin wa s 0.13 mg/1.0 g Ti. The albumin-Ti association constant was 2.77 mL/mg . Pretreatment of Ti with calcium, or magnesium alone, or combined wit h increasing pH values (3.0-7.0) resulted in augmented adsorption of H SA to Ti. No increase in adsorption was observed following pretreatmen t of Ti with potassium. These results point to the involvement of elec trostatic interactions in the adsorption of HSA to Tig (C) 1997 John W iley & Sons, Inc.