Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States.
Biomacromolecules. 2011 Oct 10;12(10):3478-86. doi: 10.1021/bm2006455. Epub 2011 Sep 6.
Star polymers with poly(ethylene glycol) (PEG) arms and a degradable cationic core were synthesized by the atom transfer radical copolymerization (ATRP) of poly(ethylene glycol) methyl ether methacrylate macromonomer (PEGMA), 2-(dimethylamino)ethyl methacrylate (DMAEMA), and a disulfide dimethacrylate (cross-linker, SS) via an "arm-first" approach. The star polymers had a diameter ~15 nm and were degraded under redox conditions by glutathione treatment into individual polymeric chains due to cleavage of the disulfide cross-linker, as confirmed by dynamic light scattering. The star polymers were cultured with mouse calvarial preosteoblast-like cells, embryonic day 1, subclone 4 (MC3T3-E1.4) to determine biocompatibility. Data suggest star polymers were biocompatible, with ≥ 80% cell viability after 48 h of incubation even at high concentration (800 μg/mL). Zeta potential values varied with N/P ratio confirming complexation with siRNA. Successful cellular uptake of the star polymers in MC3T3-E1.4 cells was observed by confocal microscopy and flow cytometry after 24 h of incubation.
星型聚合物具有聚乙二醇（PEG）臂和可降解阳离子核，通过聚乙二醇甲醚甲基丙烯酸酯大分子单体（PEGMA）、2-（二甲氨基）乙基甲基丙烯酸酯（DMAEMA）和二硫代二甲基丙烯酸酯（交联剂，SS）的原子转移自由基共聚（ATRP）合成。星形聚合物的直径约为 15nm，并在氧化还原条件下通过谷胱甘肽处理降解为单个聚合物链，这是由于二硫键交联剂的断裂，这一点通过动态光散射得到了证实。星形聚合物与小鼠颅顶前骨前体细胞（胚胎第 1 天，亚克隆 4（MC3T3-E1.4））一起培养，以确定其生物相容性。数据表明，星形聚合物具有生物相容性，即使在高浓度（800μg/mL）下孵育 48 小时后，细胞存活率仍≥80%。Zeta 电位值随 N/P 比的变化而变化，证实了与 siRNA 的复合物形成。通过共聚焦显微镜和流式细胞术观察到星形聚合物在 MC3T3-E1.4 细胞中的摄取。
