This thesis deals with the interactions of biomolecules, mainly proteins, on TiO2 and some other selected surfaces found on implants. The main focus lies in the kinetics of the adsorption processes occurring first when a titanium implant is placed in the human body. These can be monitored with high precision and sensitivity using optical waveguides. The work includes some modifications to the OWLS (Optical Waveguide Lightmode Spectroscopy) instrument, which are necessary to obtain contaminant-free adsorption measurements under controlled conditions, as checked by XPS and ToF-SIMS. Further, a focused laser beam was added to permit spatial resolution and, in conjunction with half-coated waveguides, to enable adsorption studies on two different surfaces within one experiment in real time. Optical waveguides, coated with TiO2 (Al2O3, Nb2O5, Steel) by magnetron sputtering were used for all kinetic measurements, from those of single proteins, serum and plasma solutions up to the final cell studies. Due to the modifications on the instrument, a complete rewrite of the measuring software was necessary. The software now also includes advanced plotting capabilities as well as its own p-code compiler which enables the user to add any desired functionality and which was used to carry out all the calculations in this work.
Swiss Federal Institute Of Technology Zurich