warfarin and ethylene-dimethacrylate

The relationship between molecularly imprinted polymer (MIP) morphology and template-rebinding over a series of warfarin-imprinted methacrylic acid co(ethylene dimethacrylate) polymers has been explored. Detailed investigations of the nature of template recognition revealed that an optimal template binding was obtained with polymers possessing a narrow population of pores (~3-4 nm) in the mesopore size range. Importantly, the warfarin-polymer rebinding analyses suggest strategies for regulating ligand binding capacity and specificity through variation of the degree of cross-linking, where polymers prepared with a lower degree of cross-linking afford higher capacity though non-specific in character. In contrast, the co-existence of specific and non-specific binding was found in conjunction with higher degrees of cross-linking and resultant meso- and macropore size distributions.

Topics: Adsorption; Cross-Linking Reagents; Isomerism; Ligands; Methacrylates; Molecular Imprinting; Molecular Structure; Nitrogen; Polymers; Porosity; Radioligand Assay; Temperature; Warfarin

Several immobilization methods were explored for the preparation of high-performance affinity monolithic columns containing human serum albumin (HSA). These monoliths were based on a copolymer of glycidyl methacrylate and ethylene dimethacrylate. In one method, the epoxy groups of this copolymer were used directly for the immobilization of HSA through its amine residues (i.e., the epoxy method); in other approaches, these epoxy groups were converted to diols for later use in the carbonyldiimidazole, disuccinimidyl carbonate, and Schiff base methods. Each HSA monolith was evaluated in terms of its total protein content and its retention of several model compounds, including (R/S)-warfarin and D/L-tryptophan. The greatest amount of immobilized HSA was obtained by the Schiff base method, whereas the epoxy method gave the lowest protein content. The Schiff base method also gave the best resolution in chiral separations of (R/S)-warfarin and D/L-tryptophan. All of the immobilization methods gave similar relative activities for HSA in its binding to (R)- and (S)-warfarin, but some differences were noted in the activity of the immobilized HSA for D- and L-tryptophan. The efficiency of these monoliths was found to be greater than that of silica-based HSA columns for (R/S)-warfarin (i.e., analytes with high retention), but little or no difference was seen for D- and L-tryptophan (analytes with weak retention).

Topics: Carbonates; Chromatography, Affinity; Epoxy Compounds; Humans; Imidazoles; Methacrylates; Molecular Structure; Schiff Bases; Sensitivity and Specificity; Serum Albumin; Stereoisomerism; Succinimides; Time Factors; Tryptophan; Warfarin