Sensing of parameters behind attachment of human plasma flbrinogens on carbon doped titanium surfaces: an optical study

摘要

Polished titanium surface and four differently carbon doped titanium surfaces are investigated to characterize adsorption and desorption of human plasma fibrinogen (HPF) molecules. The surface tension and surface energy of carbon doped titanium and other comparative titanium surfaces used in the experiments were observed by measuring optically the contact angle of water droplet on the treated surfaces. The dielectric constant of each bulk surface was measured utilizing ellipsometry in dry environment. Whereas the temporal adsorption or desorption of HPF molecules on test surfaces in background electrolyte with and without HPF molecules were measured using an optical correlator, which utilizes a diffractive optical element (DOE) in non-contact domain. The optical correlator operates in coherent and in non-coherent mode, which allows sensing of optical path differences providing information on the optical roughness (R_(opt)), contrary to the mechanical roughness obtained from atomic force microscope (AFM) profilometer, and reflectance of the surfaces immersed into a liquid. The knowledge of the parameters helps us to understand mechanisms behind attachment of HPF molecules on biomaterial surfaces in hard tissue replacement.