Self-Assembled Poly(butadiene)-b-poly(ethylene oxide) Polymersomes as Paclitaxel Carriers

In this work, self‐assembled poly(butadiene)‐ b‐poly(ethylene oxide) (PB‐PEO) polymersomes (polymer vesicles) and worm micelles were evaluated as paclitaxel carriers. Paclitaxel was successfully incorporated into PB‐PEO polymersomes and worm micelles. The loading capacity of paclitaxel inside PB‐PEO colloids ranged from 6.7% to 13.7% w/w, depending on the morphology of copolymer colloids and the molecular weight of diblock copolymer. Paclitaxel loaded OB4 (PB219‐PEO121) polymersome formulations were colloidally stable for 4 months at 4 °C and exhibited slow steady release of paclitaxel over a 5 week period at 37 °C. Evaluation of the in vitro cytotoxicity of paclitaxel‐polymersome formulations showed that the ability of paclitaxel‐loaded polymersomes to inhibit proliferation of MCF‐7 human breast cancer cells was less compared to paclitaxel alone. By increasing the concentration of paclitaxel in polymersomes from 0.02 to 0.2 μg/mL, paclitaxel‐polymersome formulations showed comparable activity in inhibiting the growth of MCF‐7 cells. Taken together, these results demonstrate that paclitaxel‐polymersomes have desirable restrained release profile and exhibit long‐term stability.