A pH sensitive polymeric micelle for co-delivery of doxorubicin and alpha-TOS for colon cancer therapy

作者:Debele Tilahun Ayane; Lee Kuan Yi; Hsu Ning Yu; Chiang Yi Ting; Yu Lu Yi; Shen Yao An; Lo Chun Liang
来源:Journal of Materials Chemistry B, 2017, 5(29): 5870-5880.
DOI:10.1039/c7tb01031a

摘要

Combination therapy through simultaneous delivery of two or more therapeutic agents using nanocarriers has emerged as an advanced tactic for cancer treatment. To ensure that two therapeutic agents can be co-delivered and rapidly release their cargo in tumor cells, a biocompatible pH-sensitive copolymer, methoxy poly(ethylene glycol)-b-poly(hydroxypropyl methacrylamide-g-alpha-tocopheryl succinateg- histidine) (abbreviated as PTH), was designed and synthesized. The PTH copolymers spontaneously self-assembled into micellar-type nanoparticles in aqueous solutions and are used for co-delivery of therapeutic agents, doxorubicin (Dox) and alpha-TOS. During micellization, pi-pi stacking occurred between Dox/alpha-TOS and imidazole rings of PTH copolymers inducing a regular and tight arrangement of copolymers and drugs to form rod-like micelles, thus efficiently increasing the drug loading and encapsulation efficiency. The micelles enabled the rapid release of both Dox and alpha-TOS when the pH decreased from 7.4 to 4.5. The protein adsorption assay revealed that low amounts of IgG and BSA were adsorbed on the micelles. In vivo biodistribution demonstrated that the micelles could largely accumulate in the tumor tissues. Furthermore, drug-loaded micelles treated with HCT116 cancer cells exhibited higher cytotoxicity than normal cells, which confirmed that alpha-TOS exhibited a synergy effect with Dox towards cancer cells, while no recognizable side effects were observed during the treatment from organ function tests.