| Molecular imprinting is a kind of technique which creates an affinity matrixcomplemental toward the template molecules by co-polymerization of the functionalmonomers and cross-linkers around them. Compared with the nature receptor, themolecular imprint polymers possess the feature of reliability, low cost and reusability.Resent years, molecular imprinting toward smaller molecular have a greatdevelopment and wide application.However, when compared with small molecules,the imprinting of bio-macromolecules particularly protein developed relatively slowand immaturely. There are many inherent problems with the protein hindering theadvancement, such as the huge molecular size, flexible conformation, complexconstruction and solubility.Taken the natural property of protein into consideration, in this paper, weprepared temperature-sensitive molecular imprinted hydrogel by adding a kind ofthermosensitive monomer, polymerized chitosan-gels and bi-functional monomerschitosan-gels by graft copolymerization. We investigated the adsorbability andselectivity of the prepared MIPs, made a preliminary study in the area of proteinpurification. The detail contents were shown as the following:（1）The synthesise of thermosensitive hydrogels and selectively recognizationfor the template BSAA new type of temperature-responsive imprinted hydrogels was synthesized byintroducing a kind of thermosensitive monomer N’N-isopropyl acrylamide (NIPAAm).The polymeration was conducted at frozen (-20°C) and room (25°C) temperature forthe template protein BSA. The obtained thermosensitive hydrogels were characterizedby FESEM and ATR FT-IR spectrometer. Two kinds of function monomers,acrylamide (AAm) and2-Hydroxyethyl methacrylate (HEMA), were compared.Theswelling ratio and thermosensitivity of the hydrogels were investigated. Theselectivity was evaluated and verified by direct adsorption of the single referenceprotein, as well as the SDS-PAGE technique. The results of the experiments provedthat the obtained thermosensitive hydrogels could sensitively respond to thetemperature stimulus. Frozen polymeration (-20°C) was beneficial to formcomplemental three-dimensional net structure. The maximum theoretic adsorptioncapacity were95.97mg/g and82.58mg/g for the hydrogels prepared at-20°C and25°C respectively. The equilibrium time and concentration were20h and2.0mg/mL.SDS-PAGE analysis results displayed that the thermosensitive hydrogels had perfect affinity for the BSA and could pecial recognition the targate monomer from theprotein mixture sampale.(2) The study of molecular imprinted chitosan-gel and and selectivelyrecognization for the template ovalbuminA kind of chitosan-gel was synthesized via homogeneous graft copolymerizationfor the recognition of the template ovalbumin. The acrylamide (AAm), acrylic acid(AA), methyl acrylic acid (MAA),2-Hydroxyethyl methacrylate (HEMA) werechosen as the functional monomers for the imprinted polymer gels respectively. Theapparent morphology was recorded by the FESEM. The infrared absorption before andafter the binding process was characterized by ATR FT-IR spectrometer. The influenceof function monomers amount, cross-link degree and polymeration temperature on thechitosan-gels was tested. The adsorption capacities and selectivity properties for thetemplate ovalbumin were investigated via the HPLC analysis. The results shows thatthe chitosan gels composed of AAm and MAA proved to have a relatively betterImprinting Factor (1.472and1.237respectively). Acidity polymerization condition(pH=4.7) was good for this kind of chitosan-gels. Both the FT-IR spectrometer andZeta potentiometric analysis before and after binding with the template ovalbuminproved the existence of the hydrogen bond. HPLC analysis results displayed that thebinding sites could well maintain its affinity to the template, enventhough theexistence of the competitive protein lysozyme.(3) The preparation and study of bi-functional monomers molecular imprintedchitosan-gelA kind of bi-functional monomers chitosan-gel was synthesized via combinedcopolymerization. The acrylamide (AAm) and methyl acrylic acid (MAA) wereselected as the functional monomers. The2-acrylamido-2-methyl-propanosulfonicacid (AMPS) was chosen as the binding monomers. The influence of functionmonomers ratio and cross-link degree was tested and optimized. The adsorptioncapacities and selectivity properties of bi-functional monomers chitosan-gel for thetarget molecule were tested and assessed. The results implied that the best ratio ofAAm（MAA）to AMPS was10:1. The equilibrium time and concentration of thebi-functional monomers chitosan-gel were22h and1.5mg/mL respectively. Theconcetration change of the competitive protein lysozyme had little effect on theselective recognition performance... |
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