Hu Yang, Yu Changjun, Zhang Hong, Wang Jishuai, Jiang Guoqiang, Kan Chengyou
J Nanosci Nanotechnol. 2017 Feb;17(2):900-07. doi: 10.1166/jnn.2017.12691.
Monodispersed pH-sensitive poly(styrene-co-N,N′-dimethylaminoethyl methacrylate) (P(St-co- DMAEMA)) nanoparticles (NPs) were synthesized by emulsion polymerization for use in potential applications in targeted drug delivery to the tumor microenvironment. pH-Sensitive volume swelling and drug release of the NPs with varied St/DMAEMA molar ratios, crosslinking degrees and model drug coumarin-6 loading were explored in vitro to elucidate the pH-sensitive drug release mechanisms. The swelling of the NPs, which accounts for the electrostatic repulsion of protonated tertiary amine groups under acidic conditions, reaches maximum at low pH, low crosslinking density and high DMAEMA content. The NPs undergo a pH-triggered drug release, and under the condition of pH 5 and pH 2, the average release rate during 24 h is 1.5-fold and 3-fold higher than that at physiological pH, respectively. The pH-triggered drug release is related to pH-sensitive swelling, polymer chain flexibility and drug-polymer interaction, and is significantly impacted by the St/DMAEMA molar ratio, degree of crosslinking and drug loading.
通过乳液聚合合成了单分散的pH敏感型聚（苯乙烯 - 共 - N，N′ - 二甲基氨基乙基甲基丙烯酸酯）（P（St - co - DMAEMA））纳米颗粒（NPs），用于在肿瘤微环境的靶向药物递送中的潜在应用。体外研究了具有不同St / DMAEMA摩尔比、交联度和模型药物香豆素 - 6负载量的NPs的pH敏感体积膨胀和药物释放，以阐明pH敏感药物释放机制。NPs的膨胀在低pH、低交联密度和高DMAEMA含量下达到最大值，这是由于酸性条件下质子化叔胺基团的静电排斥作用。NPs经历pH触发的药物释放，在pH 5和pH 2的条件下，24小时内的平均释放速率分别比生理pH下高1.5倍和3倍。pH触发的药物释放与pH敏感膨胀、聚合物链柔韧性和药物 - 聚合物相互作用有关，并且受到St / DMAEMA摩尔比、交联度和药物负载量的显著影响。
