Biomaterials protein adsorption

Biomaterials with Low Thrombogenicity. Poly(ethylene oxide) exhibits extraordinary inertness toward most proteins and biological macromolecules. The polymer is therefore used in bulk and surface modification of biomaterials to develop antithrombogenic surfaces for blood contacting materials. Such modified surfaces result in reduced concentrations of ceU adhesion and protein adsorption when compared to the nonmodifted surfaces. 

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. 

Tengvall P, Lundstrom I, Liedberg B (1998) Protein adsorption studies on model organic surfaces an ellipsometric and infrared spectroscopic approach. Biomaterials 19 407-422... 

Arima Y, Iwata H (2007) Effect of wettability and surface functional groups on protein adsorption and cell adhesion using well-defined mixed self-assembled monolayers. Biomaterials 28 3074-3082... 

El wing, H., Protein adsorption and ellipsometry in biomaterial research, Biomaterials 1998, 19,397 406... 

This proposal describes the development of a new, systematic approach for qualitatively and quantitatively studying surface-biomolecule interactions by matrix-assisted laser desorption ionization (MALDl) mass spectrometry (MS). This methodology is being developed because of the profound importance that surface-biomolecule interactions play in applications where biomaterials come into contact with complex biological fluids, it can readily be shown that undesired reactions occurring in response to surface-biomolecule contact (protein adsorption, biofouling, immune response activation, etc.) lead to enormous economic and human costs. Thus, the development of analytical methodologies that allow for efficient assessment of the properties of new biomaterials and/or the study of detailed fundamental processes initiated upon surface-biomolecule contact are of critical value ... 

Hydrophilicity and hydrophobicity are the most fundamental properties to be controlled for materials whenever they are utilized in biomedical devices. Protein-adsorption behavior on several biomaterials of different hydrophilicity was discussed by comparing available data with two modellings (Ikada and Peppas) for the protein-adsorption process. The adsorptive behavior of poly(HEMA) carrying polyamine functional groups was also discussed. It is well-known that protein adsorption is the first event when any of the body fluids encounters an artificial material. 

In this section, we will highlight the use of the grafting technique for designing polymeric biomaterial surfaces that exhibit non-fouling property, selective protein adsorption, enhanced tissue adhesion, and minimum frictional damage to mucosa membranes. 

The self-assembly and inhibition of protein adsorption by thiolated dextran monolayers at hydrophobic metal surfaces. In Ratner BD, Castner DG (eds) Surface modification of polymeric biomaterials. Plenum, New York, p 117... 

Rabinow BE, Ding YS, Qin C et al (1994) Biomaterials with permanent hydrophilic surfaces and low-protein adsorption properties. J Biomater Sci Polym Ed 6 91-109... 

Park JH, Bae YH (2002) Hydrogels based on poly(ethylene oxide) and poly(tetramethylene oxide) or poly(dimethylsiloxane) synthesis, characterization, in vitro protein adsorption and platelet adhesion. Biomaterials 23 1797-1808... 

Green RJ, Davies MC, Roberts CJ et al (1999) Competitive protein adsorption as observed by surface plasmon resonance. Biomaterials 20(4) 385-391... 

Specific domains of proteins (for example, those mentioned in the section Organic Phase ) adsorbed to biomaterial surfaces interact with select cell membrane receptors (Fig. 8) accessibility of adhesive domains (such as specific amino acid sequences) of select adsorbed proteins may either enhance or inhibit subsequent cell (such as osteoblast) attachment (Schakenraad, 1996). Several studies have provided evidence that properties (such as chemistry, charge, and topography) of biomaterial surfaces dictate select interactions (such as type, concentration, and conformation or bioactivity) of plasma proteins (Sinha and Tuan, 1996 Horbett, 1993 Horbett, 1996 Brunette, 1988 Davies, 1988 Luck et al., 1998 Curtis and Wilkinson, 1997). Albumin has been the protein of choice in protein-adsorption investigations because of availability, low cost (compared to other proteins contained in serum), and, most importantly, well-documented conformation or bioactive structure (Horbett, 1993) recently, however, a number of research groups have started to examine protein (such as fibronectin and vitronectin) interactions with material surfaces that are more pertinent to subsequent cell adhesion (Luck et al., 1998 Degasne et al., 1999 Dalton et al., 1995 Lopes et al., 1999). 

Recent studies have attempted to further elucidate mechanisms of protein adsorption on biomaterial surfaces. For example, Ellingsen (1991) reported that adsorption of calcium on titanium surfaces subsequently enhanced binding of select proteins. In contrast, adsorption of other ions (such as... 

Keywords Biomaterials Blood compatibility Surface modification Polyurethane Hydrogen bond Endothelialization Protein adsorption... 

Despite of hybridization with biological ligands, the general strategy for optimizing protein adsorption on biomaterial surfaces relies on chemical or physicochemical modulation of surface hydrophilicity [38,39]. The common approach is surface immobilization of hydrophilic polymers like polyethylene glycol [PEG] or polysaccharides. Four categories of surface-modification pathways have been developed ... 

Biomaterials are non-viable materials used in medical devices, which are biocompatible with minimal non-specific protein adsorption. This paper describes some functionalization techniques of surfaces against non-specific protein adsorption, such as (1) photo-immobilization, (2) y-activation or a rf plasma modification and (3) a wet-chemical treatment. The modification changes the chemical surface composition within the first 10 nm. 

Surface-bound, neutral, hydrophilic polymers such as polyethers and polysaccharides dramatically reduce protein adsorption [26-28], The passivity of these surfaces has been attributed to steric repulsion, bound water, high polymer mobility, and excluded volume effects, all of which render adsorption unfavorable. Consequently, these polymer modified surfaces have proven useful as biomaterials. Specific applications include artificial implants, intraocular and contact lenses, and catheters. Additionally, the inherent nondenaturing properties of these compounds has led to their use as effective tethers for affinity ligands, surface-bound biochemical assays, and biosensors. 

Fortunately, highly purified HEMA became available (from Hydro Med Sciences) about this time, and other monomers were readily purified by vacuum distillation. The poly (HEMA) hydrogels made with the purified HEMA showed far lower protein adsorption from either water or buffered saline than hydrogels made with the commercially available HEMA as experiment C, Table I shows. These results emphasize the biological importance of hydrogel composition in particular and biomaterial composition and purity in general. 

---