Investigation of the Peptide Adsorption on ZrO₂, TiZr, and TiO₂ Surfaces as a Method for Surface Modification

Specific surface binding peptides offer a versatile and interesting possibility for the development of biocompatible implant materials. Therefore, eight peptide sequences were examined in regard to their adsorption on zirconium oxide (ZrO₂), titanium zircon (TiZr), and titanium (c.p. Ti). Surface plasmon resonance (SPR) measurements were performed on Ti coated sensor chips to determine the kinetics of the interactions and kinetic rate constants (<i>k</i>_on, <i>k</i>_off, <i>K</i>_D, and <i>R</i>_max). We also investigated the interactions which are present in our system. Electrostatic and coordinative interactions were found to play a major role in the adsorption process. Four of the eight examined peptide sequences showed a significant adsorption on all investigated materials. Moreover, the two peptides with the highest adsorption could be quantified (up to 370 pmol/cm²). For potential biomaterials applications, we proved the stability of the adsorption of selected peptides in cell culture media, under competition with proteins and at body temperature (37 °C), and their biocompatibility via their effects on the adhesion and proliferation of human mesenchymal stem cells (hMSCs). The results qualify the peptides as anchor peptides for the biofunctionalization of implants