Studies On Metallothionein-Imprinted Polymers

Metallothioneins (MTs) are a super-family of low molecular weight, high thiolate sulfur and metal content active proteins. On the basis of review to the progress of primary theory,preparation and application of molecular imprinted technology (MIT), the polymers that had high recognition and selectivity properties to imprinted molecule were prepared, the polymers were characterized by static adsorption,differential adsorption and scanning electron microscopy (SEM), and imprinted mechanism of MT-imprinted polymer was studied first. The primary experiments and conclusions were as follows:â‘ The processing techniques of rough MT and purified MT were studied in industry. The concentration changes of MT in liver, kidney and lung were studied after inducement, and injection times, sodium chloride injection as inducement reagent were investigated as while.â‘¡Using MT as template molecule, acrylic acid (AA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker, 2,2'-azobis(2-methylpropionitrile) (AIBN) as initiator, MT-imprinted polymer was synthesized by precipitation polymerization. Polymeric factors including volume of AA, EGDMA and weight of AIBN, effect of different particle diameters, static adsorption and release ratio were investigated. The experiment results showed, when 5mg MT were used as imprinted molecule, the best proportion of AA and EGDMA was 1:2 (V/V); smaller the particle diameter was, adsorption capacity was better; the adsorption balance time of imprinted polymer is 4h, the release ratio is 54.91%.â‘¢MT-imprinted polymer was prepared by bulk polymerization. The polymeric factors and solvent were selected and optimized. When the best proportion of AA and EGDMA was 1:1 (V/V), the imprinted polymer prepared by UV light initiation under 0℃had good adsorption capacity. Differential experiment showed MT-imprinted polymer has marked selectivity to MT.â‘£On the base of former researches, MT-imprinted composite membranes (MT-ICMs) were prepared by UV light initiation. In order to get a better membrane, three membranes using Nylon, PVDF, PTFE as supports had been prepared, and their characterizations had been compared by investigating their adsorption capacities. The imprinted composite membrane with nylon had the advantages of uniform surface, better tenacity and high selectivity to MT. The balance time of adsorption and releasing time were short, which was in favor of application in industry to purifying MT, and the research would provide an experimental foundation to its production application.⑤MT imprinted nanoparticles films were synthesized via surface sol-gel process, and TiO₂ sol as imprinted matrix. In-situ technique of quartz crystal microbalance (QCM) was employed to study the adsorption and molecular imprinted behavior on TiO₂ nanoparticles films. The adsorption amount of MT on the imprinted thin film surface was almost three times as much as that on non-imprinted film, the adsorption equilibrium constant was 47.9L·g^-1(the concentration of MT is 0.4mg/mL). Compared to other proteins, the imprinted film showed the marked selectivity recognition to MT, the adsorption amount of other protein on MT-imprinted film was smaller that that of MT. The good result would provide an experimental foundation to study characterization of MT and its application.â‘¥The imprinted mechanism of MT-imprinted polymer was studied primarily by infrared spectra, equilibrium binding, Scatchard analysis and transmission electron microscopy (TEM). The interaction between MT and AA was expressed by infrared spectra, the functional groups of -SH in MT had lone pair electrons, which could formÏ€-Ï€with -C=O in AA. The equilibrium binding experiment and Scatchard analysis showed, at least three kinds of binding sites would exist when MT-imprinted polymer formed, the most adsorption capacities were 3.3896mg/g, 0.9362mg/g, 1.6583mg/g respectively; most terminal thiolate sulfurs in MT were polymerized as binding sites in the process of polymerization, which could observed from TEM, binding capability of other thiolate sulfurs was weak since spatial hindrance existed.The study in this paper can not only provide a new method and an experimental foundation to further investigate molecular imprinted technology on separation and purification of MT, but also shorten production technology and promote btter application of MT.