School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384, People's Republic of China.
J Biomed Mater Res A. 2013 Aug;101(8):2164-73. doi: 10.1002/jbm.a.34519. Epub 2012 Dec 22.
Hollow microcapsules, composed of pH responsive polyelectrolytes via a layer-by-layer (LBL) adsorption technique, were prepared. Linear or star-shaped poly(glycerol metha crylate)s (PGOHMAs) modified with 1,4-butanediamine and 1,2-ethanediamine (EDA) were synthesized and used as polycations. Poly(acrylic acid) was employed as polyanion and SiO2 (about 170 nm) as template. After LBL absorption, SiO2 cores were removed by HF treatment. The particle size and zeta potential were measured by dynamic light scattering, showing that the diameter of star-shaped amino-PGOHMA was larger than linear counterpart. The LBL assembly and core-etching process were evidenced by scanning electron microscope, transmission electron microscope, and energy dispersive spectrometer. The cytotoxicity experiments on human umbilical vein endothelial cells were carried out to evaluate the toxicity of LBL assembly. The star-shaped and EDA-modified PGOHMA exhibited better cell viability. The microcapsules were then used to load an anticancer drug, doxorubicin hydrochloride. High loading capacity (about 42%) and entrapment efficiency (84%) were obtained for star-shaped polymer-based microcapsules. The cumulative release rate was evaluated in vitro, showing faster release at an acidic condition compared to neutral pH. Confocal laser scanning microscopy evidenced the successful cellular uptake of DOX-loaded microparticles.
采用层层（LBL）吸附技术制备了由 pH 响应性聚电解质组成的中空微胶囊。合成了用 1,4-丁二胺和 1,2-乙二胺（EDA）改性的线性或星形聚（甘油甲基丙烯酸酯）（PGOHMAs），并将其用作聚阳离子。将聚丙烯酸用作聚阴离子，并将 SiO2（约 170nm）用作模板。LBL 吸收后，通过 HF 处理去除 SiO2 核。通过动态光散射测量了粒径和 Zeta 电位，结果表明星形氨基-PGOHMA 的直径大于线性对应物。通过扫描电子显微镜、透射电子显微镜和能量色散光谱仪证明了 LBL 组装和核蚀刻过程。通过人脐静脉内皮细胞的细胞毒性实验评估 LBL 组装的毒性。星形和 EDA 改性的 PGOHMA 表现出更好的细胞活力。然后将微胶囊用于装载抗癌药物盐酸阿霉素。星形聚合物基微胶囊的载药量（约 42%）和包封率（84%）较高。在体外评估了累积释放率，结果表明在酸性条件下释放速度比中性 pH 快。共聚焦激光扫描显微镜证实了 DOX 负载微粒的成功细胞摄取。
