磁性分子拓印聚合物於肌苷吸附之研究

Abstract

痛風為一種常見的關節性病變，起因於體內嘌呤代謝異常，導致高尿酸血症，而使尿酸鈣鹽沈積在關節腔內，造成關節劇烈疼痛及腫脹的疾病，因此痛風病患應避免進食高嘌呤含量的食物或飲料。 Kusunoki和Kobayashi於2010年發表了一篇以肌苷(Inosine)為標的模板分子，甲基丙烯酸(Methacrylic acid, MAA)為功能性單體，二乙烯基苯(Divinyl- benzene, DVB)為交聯劑，十二烷基苯磺酸(Laurylbenzenesulfonic acid, LBSA)為乳界面活性劑，藉由乳化聚合法(Emulsion polymerization technique)成功製備出對肌苷有專一性辨識的分子拓印聚合物(Molecularly imprinted polymers, MIPs)，期望將其應用於食品中肌苷的分離。但研究結果顯示，製備出的分子拓印聚合物會因為LBSA乳化劑的存在與否，進而影響了肌苷的吸附容量。所以，為了改善界面活性劑所造成的干擾，本研究嘗試以肌苷(Inosine)為標的模板分子，以Fe3O4 /SiO2 /γ-MPS 奈米複合粒子為核心，甲基丙烯酸為功能性單體，藉由磁性分子拓印技術(Magnetic molecularly imprinted technique, MMIT)在無乳化劑的反應環境下，製備出對肌苷具有專一性辨識的磁性分子拓印聚合物(Magnetic molecularly imprinted polymers, MMIPs)。經由穿透式電子顯微鏡(Transmission electron microscope, TEM) 掃描圖中可以觀察到MMIPs的型態為包覆均勻的圓球狀，其SiO2殼層厚度約25~30 nm，MIPs包覆殼層厚度約50~70 nm，而由動態光散射儀(Dynamic light scattering, DLS)測得的MMIPs平均粒徑為310.1± 15 nm。 最後，本研究製備的MMIPs其吸附能力Qmax1=6.01 μmol/g，解離常數KD1值為1.58 μmol/L。與Kusunoki和Kobayashi的研究結果相比較，Qmax1 吸附量為其1.5倍，且KD1值僅有其約1/10，顯示本研究製備出的MMIPs其吸附能力及親和力皆優於前人的研究。

Gout is one of the most common forms of arthritis .When the uric acid cannot be completely filtrated by kidney, it can form monosodium urate crystals and accumulate in the joints and form gout. The gout patients always need to select foods cautiously to avoid the foods or beverages that contain high concentration of purine. In 2010, Kusunoki and Kobayashi were developed the inosine-imprinted polymers microbeads which were prepared by emulsion copolymerization of divinyl- benzene (DVB) and methacrylic acid (MAA) in the presence of inosine template and laurylbenzenesulfonic acid (LBSA) as surfactant. The resulting copolymer micro- beads were observed to have a binding behavior of Inosine and surfactant to the polymer. This demonstrated that a cooperative binding with the surfactant was cooperatively occurred in the presence of inosine.In this study, magnetic molecularly imprinted polymers (MMIPs) were successfully prepared without surfactant and composed of Fe3O4 / SiO2 / γ-MPS nanocomposite particles as the core and methacrylic acid as functional monomer for specific identification of inosine. Observed by TEM, MMIPs were uniformly-coated spherical particles with the SiO2 shell thicknesses from 25 to 30 nm and the coated shell thicknesses of MIPs from 50 to 70 nm. The average diameter of MMIPs measured by DLS was 310.1 ± 15 nm. The results of adsorption experiments showed that Qmax1 was 6.01 μmol/g and KD1 was 1.58 μmol/L. Compared with Kusunoki and Kobayashi’s study, our results of Qmax1 was 1.5 times higher and the KD1 value was about 1/10, indicating that the adsorptive ability and affinity were better than previous results.