We evaluated the efficacy of pH-sensitive micelles, formed by methoxy poly(ethylene glycol)-b-poly(β-amino ester) (PEG-PAE), as carriers for paclitaxel (PTX), a drug currently used to treat various cancers. PTX was successful encapsulated by a film hydration method. Micelles encapsulated more than 70% of the PTX and the size of the PTX-encapsulated micelles (PTX-PM) was less than 150 nm. In vitro experiments indicated that the micelles were unstable below pH 6.5. After encapsulation of PTX within the micelles, dynamic light scattering (DLS) studies indicated that low pH had a similar demicellization effect. An in vitro release study indicated that PTX was slowly released at pH 7.4 (normal body conditions) but rapidly released under weakly acidic conditions (pH 6.0). We demonstrated the safety of micelles from in vitro cytotoxicity tests on HeLa cells and the in vivo anti-tumor activity of PTX-PM in B16F10 tumor-bearing mice. We concluded that these pH-sensitive micelles have potential as carriers for anti-cancer drugs.

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紫杉醇包裹的pH敏感胶束的抗肿瘤作用评估

我们评估了由甲氧基聚（乙二醇）-b形成的pH敏感胶束的功效-聚（β-氨基酯）（PEG-PAE），作为紫杉醇（PTX）的载体，紫杉醇（PTX）是目前用于治疗各种癌症的药物。通过薄膜水合作用方法成功封装了PTX。胶束封装了超过70％的PTX，而胶束封装的胶束（PTX-PM）的尺寸小于150 nm。体外实验表明，胶束在pH 6.5以下不稳定。将PTX包封在胶束中后，动态光散射（DLS）研究表明，低pH值具有相似的脱细胞作用。体外释放研究表明，PTX在pH 7.4（正常身体条件）下缓慢释放，但在弱酸性条件（pH 6.0）下迅速释放。我们通过对HeLa细胞的体外细胞毒性测试以及B16F10荷瘤小鼠体内PTX-PM的体内抗肿瘤活性证明了胶束的安全性。