Biomaterials fibrinogen

Chen et al. utUized a direct chemical reaction with a given solution (wet treatment) to modify the surface of the silicone rubber. The presence of a layer of PEO on a biomaterial surface is accompanied by reductions in protein adsorption, and cell and bacterial adhesion. In order to obtain a PEO layer on top of the silicone rabber surface, the surface was firstly modihed by incorporating an Si-H bond using (MeHSiO) , and followed by PEO grafting to the surface using a platinum-catalyzed hydrosilylation reaction. These PEO-modified surfaces were demonstrated by fibrinogen adsorption both from buffer and plasma, as well as albumin adsorption from buffer. Reductions in protein adsorption of as much as 90% were noted on these surfaces. 

Hydrophobically modified HA derivatives,91 obtained through the partial esterification of the HA carboxyl groups with methylprednisolone (45% in HYCp45 and 60% in HYCp60),92 have been deeply studied 93 A key point prior to any in vivo study of the biomaterial is the assessment of the so-called "stealth character" of the species itself. Such characteristic corresponds to be invisible towards the immune system, so that colloids are not recognized as foreign objects by body fluid components, as plasma proteins fibrinogen, BSA and lipidic components.94,95... 

Cooper et al. [21, 22] reported in detail the results of their laborious work on the adsorption of four proteins human serum albumin (HSA), fibrinogen (FGN), fibronectin (FN), and vitronectin (VN), on five biomaterials polyethylene (PE), silicone rubber (SR), Teflon-FEP (FEP), poly(tetramethylene oxide)-poly-urethane (PTMO-PU), and polyethylene oxide)-polyurethane(PEO-PU). Hard segments of these polyurethanes are composed of a methylene-bis(p-phenylisocyanate) (MDI) chain extended wih 1,4-butanediol. 

Brash, J.L. and Uniyal, S., Dependence of albumin-fibrinogen simple and competitive adsorption on surface properties of biomaterials, J. Polymer Sci., C66, 377-389 1979. 

Zdolsek J, Eaton JW, Tang L. Histamine release and fibrinogen adsorption mediate acute inflammatory responses to biomaterial implants in humans. Journal of Translational Medicine 2007, 5, 31. 

Shen M, Pan YV, Wagner MS, Hauch KD, Castner DG, Ratner BD, Horbett TA. Inhibition of monocyte adhesion and fibrinogen adsorption on glow discharge plasma deposited tetraethylene glycol dimethyl ether. Journal of Biomaterials Science, Polymer Edition 2001, 12, 961-978. 

Fabriziushoman DJ, Cooper SL (1991) Competitive adsorption of vitronectin with albumin, fibrinogen, and fibronectin on polymeric biomaterials. J Biomed Mater Res 25(8) 953-971... 

Charville GW, Hetrick EM, Geer CB et al. (2008) Reduced bacterial adhesion to fibrinogen-coated substrates via nitric oxide release. Biomaterials 29 4039 1044... 

Macromolecules of importance to the biomaterials scientist having some portion composed of a helical structure include hemoglobin, myosin, actin, fibrinogen, and keratin. The a helix is a rather condensed structure because the rise per residue is 1.5 A and as such is quite different from that of the collagen triple helix and the p structure of silk. The rise per residue in the two latter structures is about twice that found in the a helical structure. For this reason the extensibility of the a helix is greater than that of the collagen triple helix and the p structure and in the case of keratin, tensile deformation of the a helix leads to formation of a p structure. 

A study has been carried out on the interactions of blood with plasticised poly(vinyl chloride) biomaterials in a tubular form. The influence of different factors such as the biomaterial, antithrombotic agent, blood condition and the nature of the application is represented when considering the blood response in the clinical utilisation of the plasticised PVC. The PVC was plasticised with di-(2-ethylhexyl)phthalate (DEHP) and tri-(2-ethylhexyl)trimellitate (TEHTM)and in-vitro and ex-vivo procedures used to study the biomaterial with respect to the selection of the plasticiser. The blood response was measured in terms of the measurement of fibrinogen adsorption capacity, thrombin-antithrombin III complex and the complement component C3a. X-ray photoelectron spectroscopy was used for surface characterisation of the polymers and the data obtained indicated that in comparison with DEHP-PVC, there is a higher reactivity... 

Although the data show a relationship between the ability of a surface to adsorb fibrinogen out of plasma, the plasma s inability to convert this fibrinogen, and the tendency of platelets to adhere, it does not confirm that adsorption of fibrinogen must precede adhesion of platelets to all kinds of surface, or that surfaces which adsorb fibrinogen under these conditions will be bad biomaterials in vivo as heart valves, blood vessels, or canulae, or ex vivo as artificial kidney membranes—even though the latter are most likely to be impeded by any adsorbate. 

Almany, L., Seliktar, D. Biosynthetic hydrogel scaffolds made from fibrinogen and polyethylene glycol for 3D cell cultures. Biomaterials 26, 2467-2477 (2005)... 

Linnes, M.P., Ratner, B.D., Giachelli, C.M. A fibrinogen-based precision microporous scaffold for tissue engineering. Biomaterials 28, 5298-5306 (2007)... 

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). 

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