Gambogic acid-encapsulated polymeric micelles improved therapeutic effects on pancreatic cancer

Abstract

Gambogic acid (GA) is a natural product with potent anticancer activity in vitro. However, poor water solubility and systematic toxicity limit the further clinical application of GA. Micellization of hydrophobic molecule could effectively ameliorate aqueous dispersity of GA and induce better blood retention and tumor accumulation, hence lead to improved stability and therapeutic effect of GA. In this study, monomethyl poly(ethylene glycol)-poly(ε-caprolactone)-poly(trimethylene carbonate) (MPEG-P(CL-ran-TMC)) was used to encapsulate GA by a single-step solid dispersion method to form a GA encapsulated MPEG-P(CL-ran-TMC) micelles (GA micelles). GA micelles were characterized with a small particle size (44 ± 1 nm), high drug loading content (26.28% ± 0.12%) and high-efficiency encapsulation (87.59% ± 0.41%). Compared with free GA, GA micelles showed better dispersion in water, prolonged release behavior in vitro, and enhanced tumor cellular uptake. GA micelles could also effectively induce apoptosis in AsPC-1 cells. Compared with free GA, GA micelles exhibited superior antitumor efficacy and better apoptosis induced effect in a subcutaneous xenograft mouse model of AsPC-1 cells. In conclusion, GA micelles which showed high-efficiency anti-tumor effect in vitro and in vivo may serve as a candidate for pancreatic cancer therapy.