Ishihara Kazuhiko, Mu Mingwei, Konno Tomohiro, Inoue Yuuki, Fukazawa Kyoko
a Department of Materials Engineering , School of Engineering, The University of Tokyo , Tokyo , Japan.
b Department of Bioengineering , School of Engineering, The University of Tokyo , Tokyo , Japan.
J Biomater Sci Polym Ed. 2017 Jul-Aug;28(10-12):884-899. doi: 10.1080/09205063.2017.1298278. Epub 2017 Mar 3.
2-Methacryloyloxyethyl phosphorylcholine (MPC) is methacrylate bearing a phosphorylcholine group in the side chain. The phosphorylcholine group generates several unique properties arising from its zwitterionic structure, consisting of a phosphate anion and a trimethylammonium cation. Despite these charged groups, the total electrical charge of the species is zero because of the formation of an inner salt. The polymerization of MPC proceeds both conventional and living radical polymerizations. And, using these method, the corresponding polymer can be obtained efficiently. The product, poly(MPC), is soluble in aqueous media, even if the ionic strength of the solution is high, such as in the presence of 5.0 mol/L NaCl. The polymer does not show any surface active properties, even when the polymer concentration is greater than 1.0 g/dL. Hydration of poly(MPC) mainly occurs by hydrophobic hydration of the three methyl groups in the trimethylammonium group. Thus, this hydration induces an increase in a clathrate cage structure of surrounding water molecules, i.e. an ice-like water state is formed. Because of this unique hydration, poly(MPC) cannot make strong interactions with proteins and cells. Some biomedical applications have used poly(MPC) as a protein and solid-surface modification agents.
2-甲基丙烯酰氧乙基磷酰胆碱（MPC）是一种在侧链带有磷酰胆碱基团的甲基丙烯酸酯。磷酰胆碱基团因其两性离子结构产生了几种独特的性质，该结构由一个磷酸根阴离子和一个三甲基铵阳离子组成。尽管有这些带电基团，但由于形成了内盐，该物质的总电荷为零。MPC的聚合可通过传统自由基聚合和活性自由基聚合进行。并且，使用这些方法可以高效地获得相应的聚合物。产物聚（MPC）可溶于水性介质，即使溶液的离子强度很高，例如在存在5.0 mol/L氯化钠的情况下。即使聚合物浓度大于1.0 g/dL，该聚合物也不表现出任何表面活性性质。聚（MPC）的水合主要通过三甲基铵基团中三个甲基的疏水水合作用发生。因此，这种水合作用会导致周围水分子的笼形包合物结构增加，即形成类似冰的水状态。由于这种独特的水合作用，聚（MPC）不能与蛋白质和细胞形成强相互作用。一些生物医学应用已将聚（MPC）用作蛋白质和固体表面改性剂。
