Anticancer Evaluation of Methoxy Poly(Ethylene Glycol)--Poly(Caprolactone) Polymeric Micelles Encapsulating Fenbendazole and Rapamycin in Ovarian Cancer.

Purpose: We aimed to inhibit ovarian cancer (OC) development by interfering with microtubule polymerization and inhibiting mTOR signaling. To achieve this, previously developed micelles containing fenbendazole and rapamycin were applied.

Methods: Herein, we prepared micelles for drug delivery using fenbendazole and rapamycin at a 1:2 molar ratio and methoxy poly(ethylene glycol)--poly(caprolactone)(mPEG--PCL) via freeze-drying. We revealed their long-term storage capacity of up to 120 days. Furthermore, a cytotoxicity test was performed on the OC cell line HeyA8, and an orthotopic model was established for evaluating in vivo antitumor efficacy.

Results: Fenbendazole/rapamycin-loaded mPEG--PCL micelle (M-FR) had an average particle size of 37.2 ± 1.10 nm, a zeta potential of -0.07 ± 0.09 mV, and a polydispersity index of 0.20 ± 0.02. Additionally, the average encapsulation efficiency of fenbendazole was 75.7 ± 4.61% and that of rapamycin was 98.0 ± 1.97%. In the clonogenic assay, M-FR was 6.9 times more effective than that free fenbendazole/rapamycin. The in vitro drug release profile showed slower release in the combination formulation than in the single formulation.

Conclusion: There was no toxicity, and tumor growth was suppressed substantially by our formulation compared with that seen with the control. The findings of our study lay a foundation for using fenbendazole and rapamycin for OC treatment.