Fibrinogen FTIR spectroscopy

Fig. 3.7 Adsorption of fibrinogen on an EG2/EG6 gradient at pH 7.4. The incremental changes in ellipsometric thickness (filled circles) and the integrated area of the amide I peak obtained by FTIR-spectroscopy (open circles) are displayed...

FTIR spectroscopy has proven to be particularly useful in gaining an understanding of the biocompatibility phenomenon. It is believed [746, 841, 856, 857] that protein adsorption is the initial step in the interaction of blood with implanted biomaterials, followed by adhesion of cells and subsequent tissue attachment. This implies that the substrate surface characteristics influence the process, which was confirmed by ATR studies of albumin adsorption on calcium phosphate bioceramics and titanium [763] and segmented polyurethane [764], albumin and fibrinogen on acetylated and unmodified cellulose [765, 766], poly(acrylic acid)-mucin bioadhesion [767], polyurethane-blood contact surfaces [768], and other proteins on poly(ester)urethane [769], polystyrene [767, 771] and poly(octadecyl methacrylate) [771] and by IRRAS study of adsorption of proteins on Cu [858]. Another branch of IR spectroscopic studies of protein adsorption relates to microbial adhesion (Section 7.8.3). 

Interaction of HPF with nanosilica is of special interest because of the medical applications of this material, especially as a component of tourniquet preparations. Therefore, here we will analyze adsorption interactions of fibrinogen with nanosilica depending on concentration of components, salinity, and pH. Application of several methods such as (i) adsorption of HPF from the aqueous solutions (ii) UV and FTIR spectroscopy of adsorbed layer with HPF and (iii) TSDC and H NMR spectroscopy with layer-by-layer freezing-out of bulk and bound water interacting with HPF and HPF/nanosilica allows us to deeply understand features of interaction of HPF with silica NP that is of importance for elucidation of the mechanism of interaction of nanosilica preparations with blood. 

Very little of the research that has been done on these proteins has involved the use of electrochemical techniques. Instead, ellipsometry, FTIR/ATR spectroscopy, radioactive labeling, and photon correlation spectroscopy have been used. Many of the studies have been directed toward the development of biocompatible polymer surfaces. The first event that takes place after contact of blood or plasma with an artificial surface is the rapid adsorption of proteins from the blood onto the material surface. It is generally assumed that all subsequent events, such as platelet adhesion and surface activation of blood coagulation, are determined by the composition and structure of the initially adsorbed protein layer. It is known from in vitro experiments that the adhesion of platelets is promoted when fibrinogen has been adsorbed on a material surface and that platelet adhesion is reduced when preadsorbed albumin is present on the surface. In a study of the adsorption behavior of three of the more abundant... 

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