In this paper we report on synthesis of pH sensitive and degradable microgel for a high-capacity doxorubicin-drug carrier. Microgel was based on poly(acrylic acid) cross-linked with a redox-sensitive linker - N,N’-bis(acryloyl)cystamine, and was synthesized by using the distillation polymerization. Highly monodispersed spherical particles were obtained. The presence of carboxylic groups in the chains gave pH-sensitivity to the microgel; as a result the microgel size changed after a change in pH. The presence of disulfide bridges in the microgels gave them the ability to degrade. The extent of degradation of the microgel was examined by using the dynamic light scattering technique and electron microscopy. The degradation of the microgel was caused by the reduction of -S-S- bridges by glutathione. At the beginning of the degradation process the swelling of the microgel particles was observed because only a part of disulfide bonds were broken. The break of the remaining -S-S- bonds led to the complete degradation of the microgel. The fact that the microgel consisted mainly of the carboxylic groups allowed us to bind a high amount of the anticancer drug. Under the conditions typical for cancer cells, i.e. at pH 5 and in the presence of increased concentration of glutathione, the highest amount of doxorubicin could be released. The MTT assay indicated that compared to free doxorubicin the microgel particles loaded with doxorubicin were more cytotoxic against the MCF-7 breast cancer cells, while they were 27 times less toxic against the MCF-10A healthy cells.

在本文中，我们报告了用于高容量阿霉素药物载体的 pH 敏感和可降解微凝胶的合成。微凝胶基于聚（丙烯酸）与氧化还原敏感接头 - N，N' 交联-双（丙烯酰基）胱胺，采用蒸馏聚合法合成。获得高度单分散的球形颗粒。链中羧基的存在使微凝胶具有 pH 敏感性；因此，微凝胶大小在 pH 值变化后发生了变化。微凝胶中二硫键的存在赋予了它们降解的能力。通过使用动态光散射技术和电子显微镜检查微凝胶的降解程度。微凝胶的降解是由谷胱甘肽减少-SS-桥引起的。在降解过程开始时，观察到微凝胶颗粒膨胀，因为只有部分二硫键断裂。剩余-SS-键的断裂导致微凝胶完全降解。微凝胶主要由羧基组成的事实使我们能够结合大量的抗癌药物。在癌细胞的典型条件下，即在 pH 5 和谷胱甘肽浓度增加的情况下，可以释放最高量的阿霉素。MTT 测定表明，与游离多柔比星相比，载有多柔比星的微凝胶颗粒对 MCF-7 乳腺癌细胞的细胞毒性更强，而对 MCF-10A 健康细胞的毒性则低 27 倍。