Fibrinogen, adsorption

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. 

Tegoulia VA, Rao W, Kalambur AT, Rabolt JF, Cooper SL (2001) Surface properties, fibrinogen adsorption, and cellular interactions of a novel phosphorylcholine-containing self-assembled monolayer on gold. Langmuir 17 4396-4404... 

Weber N, Bolikal D, Bourke SL, Kohn J (2004) Small changes in the polymer stmcture influence the adsorption behavior of fibrinogen on polymer surfaces validation of a new rapid screening technique. J Biomed Mater Res Part A 68A 496-503... 

The most widely studied synthetic polymers for blood contact applications are polyether urethane ureas ( Biomer (Ethicon)). These materials have been used in artificial hearts, as coatings for lead wires in pacemakers, have been used and are being considered for blood vessel prostheses. The success of these materials is believed to be due to preferential adsorption of albumin rather than globulin or fibrinogen which promote a clotting response. However, these materials are hydrophobic and questions of long-term effectiveness are unresolved. Particularly, these materials may shed emboli or may be susceptible to surface calcification. Thus, it may be desirable to have synthetic polymers which are hydrophilic and better resemble blood vessels [475]. 

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. 

The adsorption experiments were carried out by quantifying each of proteins adsorbed on the material from mono-component protein solutions, from four-component protein solutions, and from plasma and diluted plasma. Adsorption profiles of protein were largely different, depending on the aforementioned experimental conditions. For instance, the behavior of any particular protein from diluted plasma varied in response to the extent of plasma dilution. Cooper s results are illustrated in Fig. 3, on fibrinogen adsorption onto five polymer surfaces. It is seen that the adsorption profiles are different one another, being influenced by the different nature of the polymer surfaces. The surface concentrations of adsorbed protein are mostly time-dependent, and maxima in the adsorption profiles were observed. This is interpreted in terms of replacement of adsorbed fibrinogen molecules by other proteins later in time (Vroman effect). Corresponding profiles were also presented for FN and VN. 

As for the effect of anionic group, there are a number of reports dealing with the antithrombogenic behavior of sulfonate-modified surfaces of segmented polyurethane (SPU). An interesting feature of the adsorptive behavior of fibrinogen on these material surfaces will be discussed in Sect. 4.1. 

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. 

Recently Horbettl02) and Brash and ten Hove 103) have quantitatively demonstrated the Vroman effect in a series of experiments studying competitive adsorption of fibrinogen, albumin, IgG, and hemoglobin from diluted plasma. 

Other workers have observed concentration-dependent competitive adsorption, including Grinnell and Feld 89) (fibronectin), and Breemhaar et al. 104) (fibrinogen, IgG, albumin). 

Fig. 23. Brash and ten Hove s results on the adsorption of three plasma proteins from diluted plasma as a function of total plasma concentration. Up adsorption on glass showing a maximum adsorption of fibrinogen at about 1% plasma Down adsorption on polyethylene plasma was diluted with isotonic Tris, pH 7.35. Adsorption time was 5 minutes (reprinted from Ref.1031)...

The data on protein adsorption as affected by immobilized heparin is quite contradictory. In Refs.114> and115), serum albumin was shown to be predominantly adsorbed by the HCP, whereas in the majority of other works the observed dependence was the opposite. Table 14 compiles the results of the studies of the absorption of plasma proteins by HCP of two different types 64). Such thrombogenic proteins as fibrinogen and thrombin are seen to be the ones adsorbed most. 

Using the cage implant system, Kim et al. successfully polymerized a phospholipid on to a solid substrate and found reduced adsorption of proteins such as albumin, fibrinogen, and IgG and also reduced macrophage adhesion.80 There has also been widespread interest in the use of PC coats for orthopedic joint implants as well as other biomedical applications.81 3... 

Tang L, Wu Y, Timmons RB. Fibrinogen adsorption and host tissue responses to plasma functionalized surfaces. Journal of Biomedical Materials Research 1998, 42, 156-163. 

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. 

Cao L, Sukavaneshvar S, Ratner BD, Horbett TA. Glow discharge plasma treatment of polyethylene tubing with tetraglyme results in ultralow fibrinogen adsorption and greatly reduced platelet adhesion. Journal of Biomedical Materials Research A 2006,79,788-803. 

These kinetics studies required development of reproducible criteria of subtraction of foe H-O-H bending band of water, which completely overlaps foe Amide I (1650 cm 1) and Amide II (1550 cm"1) bands (98). In addition, correction of foe kinetic spectra of adsorbed protein layers for foe presence of "bulk" unadsorbed protein was described (99). Examination of kinetic spectra from an experiment involving a mixture of fibrinogen and albumin showed that a stable protein layer was formed on foe IRE surface, based on foe intensity of the Amide II band. Subsequent replacement of adsorbed albumin by fibrinogen followed, as monitored by foe intensity ratio of bands near 1300 cm"1 (albumin) and 1250 cm"1 (fibrinogen) (93). In addition to foe total amount of protein present at an interface, foe possible perturbation of foe secondary structure of foe protein upon adsorption is of interest. Deconvolution of foe broad Amide I,II, and m bands can provide information about foe relative amounts of a helices and f) sheet contents of aqueous protein solutions. Perturbation of foe secondary structures of several well characterized proteins were correlated with foe changes in foe deconvoluted spectra. Combining information from foe Amide I and m (1250 cm"1) bands is necessary for evaluation of protein secondary structure in solution (100). 

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... 

Slack SM, Horbett TA (1988) Physicochemical and biochemical aspects of fibrinogen adsorption from plasma and binary protein solutions onto polyethylene and glass. J Colloids Interf Sci 124(2) 535-551... 

Wertz CF, Santore MM (1999) Adsorption and relaxation kinetics of albumin and fibrinogen on hydrophobic surfaces single-species and competitive behavior. Langmuir 15(26) 8884-8894... 

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