The buildup of ordered protein systems constitutes one of the major objectives of bio-related chemistry and biotechnology. In this respect a concept has recently been reported for the fabrication of multilayers by the consecutive adsorption of positively and negatively charged polyelectrolytes. We have investigated the adsorption processes between polyelectrolyte multilayers and a series of positively and negatively charged proteins. The film building up and adsorption experiments were followed by Scanning Angle Reflectometry (SAR) and Optical Waveguide Spectroscopy (OWLS).

We have found that proteins were strongly interacted with the polyelectrolyte film whatever the sign of the charge of both the multilayer and the protein. When charges of the multilayer and the protein were similar, we observed the formation of protein monolayers which became dense aftrwards. We have also shown that when the protein and the multilayer became oppositely charged, the adsorbed amounts were usually larger and the formation of thick protein layers extending up to several times could be observed. Our results confirmed that electrostatic interactions dominate protein/polyelectrolyte multilayer interactions. In order to test the use of such film in biomedical field, we have studied the adsorption of different active coumpounds as recombinant amelogenines and nanometersized apatite crystals.