Nakayama Y, Miyamura M, Hirano Y, Goto K, Matsuda T
Department of Bioengineering, National Cardiovascular Center Research Institute, Suita, Osaka, Japan.
Biomaterials. 1999 May;20(10):963-70. doi: 10.1016/s0142-9612(98)00252-x.
This article reports a novel preparation method of poly(ethylene glycol) (PEG)-polystyrene (PST) amphiphilic block copolymers with well-defined block lengths by using photopolymerization of an iniferter, benzyl N,N-diethyldithiocarbamate. PEG macroiniferters, which were prepared by end-capping of PEG monomethyl ethers with benzyl N,N-diethyldithiocarbamate group at one end, were irradiated with UV light in the presence of styrene (ST). NMR analyses showed that the PST block was chain-extended from the PEG block, resulting in the preparation of PEG-PST block copolymers. The number-average molecular weights of the copolymers increased almost linearly with irradiation time, light intensity, and concentration of ST. The polydispersities of the copolymers remained relatively small throughout the reaction (Mw/Mn approximately 1.3). The composition of two PEG-PST block copolymers thus obtained was as follows: PEG (Mn; 1.9 x 10(3) gmol(-1))-PST (3.0 x 10(3) gmol(-1)) and PEG (4.9 x 10(3) gmol(-1))-PST (2.6 x 10(3) gmol(-1)). These copolymers were coated onto a poly(ethylene terephthalate) film surface. X-ray photoelectron spectroscopy analyses and water wettability measurements showed that the PST block was enriched at the outermost layer as cast in air, whereas upon immersion into water, the PEG block was oriented toward water. Enhanced wettability was observed for the diblock copolymer with a higher PEG content. Significantly reduced cell adhesion was observed on both the coated surfaces. Thus, the PEG-PST block copolymer may function as a cell adhesion-resistant coating which reduced cell-substrate interaction.
本文报道了一种通过使用引发转移终止剂N,N - 二乙基二硫代氨基甲酸苄酯的光聚合反应来制备具有明确嵌段长度的聚（乙二醇）（PEG） - 聚苯乙烯（PST）两亲性嵌段共聚物的新方法。PEG大分子引发转移终止剂是通过在PEG单甲醚的一端用N,N - 二乙基二硫代氨基甲酸苄酯基团封端制备的，在苯乙烯（ST）存在下用紫外光照射。核磁共振分析表明，PST嵌段从PEG嵌段进行链增长，从而制备出PEG - PST嵌段共聚物。共聚物的数均分子量随照射时间、光强度和ST浓度几乎呈线性增加。在整个反应过程中共聚物的多分散性保持相对较小（Mw/Mn约为1.3）。由此得到的两种PEG - PST嵌段共聚物的组成如下：PEG（Mn；1.9×10³ gmol⁻¹） - PST（3.0×10³ gmol⁻¹）和PEG（4.9×10³ gmol⁻¹） - PST（2.6×10³ gmol⁻¹）。这些共聚物被涂覆在聚对苯二甲酸乙二酯薄膜表面。X射线光电子能谱分析和水接触角测量表明，在空气中浇铸时PST嵌段富集在最外层，而浸入水中时，PEG嵌段朝向水定向排列。对于PEG含量较高的二嵌段共聚物观察到润湿性增强。在两种涂覆表面上均观察到细胞粘附显著降低。因此，PEG - PST嵌段共聚物可作为一种减少细胞 - 底物相互作用的抗细胞粘附涂层发挥作用。
