Kitano Hiromi, Kago Hirokazu, Matsuura Kazuhiro
Department of Applied Chemistry, Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan.
J Colloid Interface Sci. 2009 Mar 15;331(2):343-50. doi: 10.1016/j.jcis.2008.11.058. Epub 2008 Dec 3.
Polymers of 2-(2-methoxyethoxy)ethyl methacrylate (MDM) were prepared by atom transfer radical polymerization using 2-(2'-bromoisobutyroyloxy)ethyl disulfide as initiator. An aqueous solution of the disulfide-carrying polymer (DT-PMDM) turned to be opaque above certain temperature (22 degrees C for DT-PMDM (M(n)=1.69x10(4))), which was corresponding to the lower critical solution temperature (LCST) of the polymer. The disulfide-carrying polymer could be accumulated on the surface of gold colloid as a polymer brush as confirmed by the increase in absorbance at 550 nm ascribable to the localized surface plasmon resonance (LSPR). Furthermore, the polymer brush could also be constructed on a monolayer of colloidal gold that had been deposited on a glass plate beforehand. The PMDM brush on both the free and surface-confined gold colloids showed definite temperature responsiveness in the absorbance at 550 nm. Moreover, non-specific adsorption of various proteins to the surface of polymer brush on the glass plate was examined by the absorption increase at 550 nm. The PMDM brush, which had been prepared with the DT-PMDM pretreated with NaBH(4), did not adsorb lysozyme significantly below the LCST of the polymer chain, whereas substantially adsorbed the protein above the LCST. These results suggest usability of the polymer brushes with pendent omega-methoxy oligo(ethylene glycol) groups to coat various materials for biomedical applications.
以2-(2'-溴异丁酰氧基)乙基二硫化物为引发剂，通过原子转移自由基聚合制备了甲基丙烯酸2-(2-甲氧基乙氧基)乙酯(MDM)聚合物。携带二硫化物的聚合物(DT-PMDM)的水溶液在一定温度以上(DT-PMDM (M(n)=1.69x10(4))为22℃)会变得不透明，这与聚合物的低临界溶液温度(LCST)相对应。如归因于局域表面等离子体共振(LSPR)的550 nm处吸光度增加所证实的，携带二硫化物的聚合物可以作为聚合物刷积聚在金胶体表面。此外，聚合物刷也可以构建在预先沉积在玻璃板上的胶体金单层上。游离和表面受限的金胶体上的PMDM刷在550 nm处的吸光度都表现出明确的温度响应性。此外，通过550 nm处吸光度的增加来检测各种蛋白质对玻璃板上聚合物刷表面的非特异性吸附。用NaBH(4)预处理的DT-PMDM制备的PMDM刷在聚合物链的LCST以下不会显著吸附溶菌酶，而在LCST以上则会大量吸附该蛋白质。这些结果表明，带有末端ω-甲氧基聚(乙二醇)基团的聚合物刷可用于为生物医学应用涂覆各种材料。
