RESUMO
The main purpose of our investigation is to achieve better insight into the electrophoretic and thermodynamic properties of protein-coated biomaterial particles. Many academic studies have been performed to understand the complex phenomena of microscopic biomaterial particles as a function of ionic strength, pH and temperature. By electrophoretic measurements of biomaterial particles, the surface structures of it can be analysed with a suitable model. Therefore, the zeta potential measurements are useful to know the effects of adsorbed BSA concentration upon the electrophoretic properties of bioceramics and bioglasses. Unexpectedly, the zeta potential of the BSA-coated biomaterials exhibits a local minimum as the concentrations of adsorbed BSA increases. Apparently, the structures of the attached BSA layer on the biomaterial particles play a significant role. In an attempt to elaborate the phenomenon observed, a model for proteins, which composes two BSA sublayers with different structures and properties, is proposed. Also, the association or equilibrium constant were determined and represented the isotherm curves in function of the zeta potential measurements.