Poly films protein adsorption

Anderson et al. [59, 75,76] have been pursuing their extensive researches on the biomedical behavior of PEUUs having various formulations modified with hydrophobic acrylate (or methacrylate) polymer or copolymer additives. The most distinguished additive was Methacrol 2138F, which is a copolymer between diisopropylaminoethyl methacrylate and decyl methacrylate [co(DIPAM/DM)] (in a 3-to-l ratio). The protein adsorption assay showed that PEUU (Biomer-type) films loaded or coated with Methacrol or poIy(DIPAM) adsorbed significantly lower amounts of human blood proteins (Fb, IgG, factor VIII, Hageman factor and Alb) than the base PEUU or PEUUs modified by other additives. It was revealed from their experiments that poly(DIPAM) as well as Methacrol exhibited a prominent suppressing effect on the protein adsorption process. 

From the experiments it is clear that poly electrolyte is adsorbed on the surface of the black lipid film. This applies both to the experiments with gelatin and bovine serum albumin, which gave no decrease of film resistance, and to the experiments with bovine erythrocyte ghost protein and polyphosphate. The adsorption of protein on the phospholipid-water interface may be controlled independently by investigating the electrophoretic behavior of emulsion droplets, stabilized by phospholipid, in a protein solution, as a function of pH. In this way Haydon (3) established protein adsorption on the phospholipid-water interface. If the high resistance (107 ohms per sq. cm.) of black lipid films is to be ascribed to the continuous layer of hydrocarbon chains in the interior of the film, as is generally done, an increase in film conductivity is not expected from adsorption without penetration. 

The poly (HEM A) sheets were prepared by B. Ratner using a special technique he developed. The HEMA solutions were poured between glass plates, and polymerization was chemically initiated. The chemical and physical properties of this material are very similar to those of radiation-grafted poly (HEMA) insofar as protein adsorption is concerned. Heterogeneous or homogeneous poly (HEMA) films were made by polymerization in solvents in which the poly (HEMA) is insoluble or soluble, respectively the result is a white opaque material in the first case and a transparent material in the second case. The resulting films were washed free of excess monomer and then soaked in the buffer to be used in the fibrinogen adsorption experiment for 10 days at 37 °C prior to the actual experiment. 

Nagahama, K., Nishimura, Y., Ohya, Y. and Ouchi, T. (2007) Impacts of stereoregularity and stereocomplex formation on physicochemical, protein adsorption and cell adhesion behaviors of star-shaped 8-arms poly(ethylene glycol)-poly(lactide) block copolymer films. Polymer, 48, 2649-2658. 

In previous papers(i-.3), we have reported that a specially prepared poly(vinyl alcohol) (PVA) film is very low in protein adsorption and platelet adhesion compared with conventional PVA and other polymers. When PVA is used for practical applications as non aqueous solutions, physical or chemical crosslinking or acetalization is introduced to PVA to make it insoluble in water. Acetalization with formaldehyde and physical crosslinking by heat treatment (annealing) are the most common among the insolubilization methods(. However, for the minimum protein adsorption and platelet adhesion, these physical and chemical modifications have to be avoided because significant interactions with biological components are observed for such PVA, similar to the conventional polymers. 

Based on the relationship between protein adsorption and thromboge-nicity, a method was reported for fibrinogen adsorption/desorption measurements as a prescreening method. Processes for the coating of polymers with poly-acrybnitrile and with carbon were discussed, and results on layers on flat films, the inside of tubes and vascular prostheses, and on membranes were described. 

Polyethylene glycol (PEG) is another well-known molecule used to reduce protein adsorption and/or platelet adhesion. Surface enrichment of a triblock oligomeric PEG containing additive from a polyurethane matrix was reported [54,55]. The authors used PEG as the active groups to suppress protein and platelet adhesion. The authors first synthesized a methylene diphenyl diisocyanate (MDI)-poly (tetramethylene oxide) (PTMO) 1000 prepolymer with a MW of approximately 4750 (PU4750), and then this prepolymer was terminally functionalized with mono amino-polyethylene oxide (PEG) with different MW (PEO550, 2000, or 5000, Table 2.3). This triblock copolymer was mixed with a polyurethane (MDI/ PTMO 1000/ethylene diamine (ED)) at different ratios in dimethylformamide (DMF) and cast into polymer films. The surface compositions of these films were evaluated by XPS. 

Zhang F, Kang ET, Neoh KG, Wang P, Tan KL. Reactive coupling of poly(ethylene glycol) on electroactive polyanUine films for reduction in protein adsorption and platelet adhesion. Biomaterials 2002 23 787-95. 

Yang, W., Chen, S., Cheng, G., Vaisocherova, H., Xue, H., Li, W., et al. (2008). Film thickness dependence of protein adsorption from blood serum and plasma onto poly(sulfobetaine)-grafted surfaces. Langmuir, 24, 9211-9214. 

Poly(methyl methacrylate) Polymer films Reduction in plasma protein adsorption, and platelet adhesion Control of thrombus formation in cardiovascular applications... 

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