title: Design and evaluation of thin and flexible theophylline imprinted polymer membrane materials.
abstract: The aim of this work was to produce a thin, flexible and diffusion able molecularly imprinted polymeric matrix with good template accessibility. Membranes were prepared using a non-covalent molecular imprinting approach and their physical characteristics and binding capabilities investigated. Two materials were used, a poly(tri-ethyleneglycol dimethyacrylate-co-methyl methacrylate-co-methacrylic acid) copolymer containing 14% cross-linker and a monomer (g) to porogen (ml) ratio of 1:0.5 (A), and a blend of poly(TEGMA-co-MAA) and polyurethane (B). The polyurethane was added to improve membrane flexiblity and stability. The polymers were characterized using AFM, SEM and nitrogen adsorption, whilst binding was evaluated using batch-rebinding studies. For all membranes the specific surface area was low (<10 m(2)/g). MIP (A) films were shown to bind specifically at low concentrations but specific binding was masked by non-specific interactions at elevated concentrations. Selectivity studies confirmed specificity at low concentrations. K(D) approximations confirmed a difference in the population of binding sites within NIP and MIP films. The data also indicated that at low concentrations the ligand-occupied binding site population approached homogeneity. Scanning electron microscopy images of membrane (B) revealed a complex multi-layered system, however these membranes did not demonstrate specificity for the template. The results described here demonstrate how the fundamental parameters of a non-covalent molecularly imprinted system can be successfully modified in order to generate flexible and physically tolerant molecularly imprinted thin films.
authors.affiliation: Welsh School of Pharmacy, Cardiff University, Cardiff, CF10 3NB, UK.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Hillberg
authors.forename: Keith R
authors.initials: KR
authors.lastname: Brain
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Allender
mesh_terms: D000327:Adsorption; D003432:Cross-Linking Reagents / Q000737:chemistry; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D054802:Molecular Imprinting / Q000379:methods*; D009584:Nitrogen / Q000737:chemistry; D018583:Pliability; D011140:Polyurethanes / Q000737:chemistry*; D013696:Temperature; D013806:Theophylline / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D008567:Membranes, Artificial; D011140:Polyurethanes; D013806:Theophylline; D009584:Nitrogen