Investigating the acoustic release of doxorubicin from targeted micelles

The main problem associated with the administration of anti-cancer medication is that the drug is delivered throughout the body causing undesirable side effects. Therefore, it is important to synthesize drug carriers capable of minimizing the adverse side effects of chemotherapy by preferentially targeting tumor cells both actively (e.g. a folate receptor) and using external stimulus (e.g. ultrasound). In this paper, we report the synthesis of Pluronic P105 micelles with a folate targeting moiety (with a yield of 48%) containing doxorubicin (Dox). We applied low frequency ultrasound as an external stimulus and measured the amount of release of Dox from these folated micelles. The results showed that the percent drug release increases as the power intensity of ultrasound increases. The maximum amount of release (14%) was measured at 5.4 W/cm2. A power density threshold at approximately 0.55 W/cm2 exists below which no statistically significant release was observed. This lower threshold suggests that cavitation plays an important role in triggering drug release from targeted micelles.