Development of a new tri-block copolymer with a functional end and its feasibility for treatment of metastatic breast cancer

We have developed nanomedicine vehicle based on a biocompatible tri-block copolymer, poly(ethylene glycol)-block-poly(lactic acid)-block-poly(ethylene glycol) (PEG-PLA-PEG) by simple approach without toxic linker to escalate therapeutic efficacy of anticancer agent by enhanced targeting to metastasized breast cancers. The synthesized ABA type copolymer had a low polydispersity index and formed small, highly stable spherical micelles. Furthermore, a functional group at the end site of the copolymer can be decorated with imaging agents and targeting moieties. The doxorubicin loaded micelles (DLM) showed higher drug-loading capacity, faster drug release, and better cell toxicity compared to those using di-block copolymers. DLM efficiently delivered to the metastatic breast cancers in brain and bone and suppressed growing of metastasis. In demonstration of treating metastasized animal model, we present a tri-block copolymer as a potential nanomedicine vehicle to efficiently deliver anticancer drug and to effectively treat metastatic breast cancer.