MACROPOROUS GELS - FACTS AND MISFACTS

2020-03-26 16:14:57

poly media gel novel AAEE

责任者: RIGHETTI, PG 单位: UNIV MILAN,DEPT BIOMED SCI & TECHNOL,I-20133 MILAN,ITALY. 来源出处: JOURNAL OF CHROMATOGRAPHY A, v 698, APR 28 1995, p 3- 17 摘要: Some extraordinary events have occurred in the last two years which might revolutionize the field of polyacrylamide gel electrophoresis. While it was widely recognized that such matrices could normally be cast with a small pore size distribution, typically of the order of a few nanometres diameter (for protein sieving), recent developments suggest that macroporous gels could also be produced in the domain of polyacrylamides. If constraints on chain motion are imposed during gel polymerization, large-pore structures can be grown. Such constraints can originate either from low temperatures or from the presence of preformed polymers in the gelling solution; in both instances, the growing chains are forced to laterally aggregate via inter-chain hydrogen bond formation. On consumption of pendant double bonds, such bundles are frozen in the three-dimensional space by permanent cross-links. As an additional development, a novel photopolymerization system is described, consisting of a cationic dye (methylene blue) and a redox couple (sodium toluene sulphinate, a reductant, and diphenyliodonium chloride, a mild oxidant). Methylene blue catalysis is characterized by a unique efficiency, ensuring >96% conversion of monomers even in aqueous-organic solvents and in presence of surfactants, which normally quench or completely inhibit the peroxodisulphate-driven reaction. In addition, methylene blue-sustained photopolymerization can be operated in the entire pH range 3-10, where most other systems fail. Perhaps the most striking novelty in the field is the appearance of a novel monomer (N-acryloylaminoethoxyethanol, AAEE) coupling a high hydrophilicity with a unique resistance to alkaline hydrolysis. Given the fact that a poly(AAEE) matrix is 500 times more stable than a poly(acrylamide) gel, while being twice as hydrophilic, it is expected that this novel chemistry will have no difficulties in replacing the old electrophoretic anticonvective media. The review ends with a glimpse at novel sieving media in capillary zone electrophoresis: polymer networks. Such media, by providing an almost infinite range of pore sizes, owing to the absence of a rigid support, allow sieving mechanisms to be operative over a wide interval of particle sizes, even up to genomic DNA. Viscous solutions of polymer networks, made with the novel poly(AAEE) chemistry, allow the repeated use of the same separation column, well above 50 injections. Silica-bound poly(AAEE) chains provide effective quenching of electrosmosis and >200 analyses by isoelectric focusing. 关键词: POLYSTYRENE NANOPARTICLES; PEYERS PATCHES; TOMATO LECTIN; POLOXAMER; TRANSLOCATION; ORAL UPTAKE TRANSLOCATION; ORAL UPTAKE; CAPILLARY ZONE ELECTROPHORESIS; POLYACRYLAMIDE GELS; METHYLENE-BLUE; POLYMERIZATION; KINETICS; PHOTOPOLYMERIZATION; EFFICIENCY; PROTEINS; POLYMERIZATION; KINETICS; PHOTOPOLYMERIZATION; EFFICIENCY; PROTEINS; MONOMERS MONOMERS