%0 Journal Article
%T Optical Sensing of Attached Fibrinogen on Carbon Doped Titanium Surfaces
%A Raimo Silvennoinen
%A Vladim¨ªr Vetterl
%A Stanislav Haso¨¾
%A Martti Silvennoinen
%A Kari Myller
%A Ji£¿i Van£¿k
%A Ladislav Cvr£¿ek
%J Advances in Optical Technologies
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/942349
%X The adsorption/desorption of Human Plasma fibrinogen (HPF) molecules on biosurfaces was measured in spectroscopic cuvette by a diffractive optical element- (DOE-) based sensor. To characterize the surfaces, the basic parameters as surface tension was obtained by sensing of a contact angle of water droplet and dielectric constant was measured by ellipsometry in the absence of HPF molecules. It was observed a significant correlation between the adsorption ability of HPF molecules (sensed by DOE on the basis of the changes in optical roughness ( ) of studied surface in the absence and presence of HPF molecules), and dielectric constant (measured by ellipsometry) of differently treated titanium surfaces, where the permittivity and dielectric loss have the known linear relation. These findings with carbon-treated biomaterial surfaces can help us to understand mechanisms behind attachment of HPF molecules on biomaterial surfaces to realize and extend variety of implants for hard tissue replacement. 1. Introduction Titanium is frequently used as a biomaterial for hard tissue replacement, such as dental and orthopaedic implants, and biomaterial devices made of titanium give a satisfactory performance [1¨C7]. The effective surface energy related to topography of surface, which can be varied by different processing methods, is assumed to influence to the final interactions of the implant with the surrounding environment. Rough surfaces promote better osseointegration than smooth surfaces [8¨C11]. Within a few seconds after implantation the biomaterial surface becomes coated with a film of adsorbed proteins, which mediate the interaction between the implant and the body environment. Since most implants are exposed to blood during implantation, the initial protein film is mainly composed of plasma proteins. Human plasma fibrinogen (HPF) is one of the most relevant proteins adsorbed on biomaterial surfaces. HPF partakes in blood coagulation facilitate adhesion and aggregation of platelets [12, 13]. The structure and composition of the adsorbed protein layer determine the type and extent of the subsequent biological reactions, such as activation of coagulation and immune response and osseointegration [14]. The initially adsorbed protein layer is thus a factor for conditioning the biocompatibility [15¨C17]. The mechanisms and the factors, which are important for protein adsorption and desorption, are still subject of scientific research and not understood very well. Therefore it is important to investigate how different surfaces influence the formation and properties of
%U http://www.hindawi.com/journals/aot/2010/942349/