Encapsulation of Quercetin in Tri-Block-Copolymer/Tween 80 Mixed Nanomicelles to Enhance its Cytotoxicity Against Breast Cancer Cells

Abstract

Quercetin, a natural polyphenolic compound, has attracted much attention due to its great therapeutic potential against various types of diseases. But clinical applications of quercetin are limited due to its poor aqueous solubility and low bioavailability. The main purpose of this research was to evaluate the therapeutic potential of quercetin-loaded Pluronic F127 (PF127)/Tween 80 mixed nanomicelles as a passive targeted drug delivery system for breast cancer therapy. To this end, quercetin-loaded mixed nanomicelles with different mass ratios of drug:PF127:Tween 80 were prepared by the thin-film hydration method. The highest drug loading and entrapment efficiency were obtained to be 2.3% and 98.0%, respectively, for mixed micelles with drug:PF127:Tween 80 ratio of 1:40:15. The physical interactions of quercetin with PF127 and Tween 80 at optimized ratio was investigated by XRD and FTIR analyses. The mean hydrodynamic size and surface charge of prepared nanomicelles, measured by DLS and zeta potential analyses, were 22.1 nm and -7.63 mV, respectively. The results of in-vitro drug release experiments showed that, the mixed micellar system has a prolong and sustained release behavior compared to the solution of free quercetin. Moreover, the in-vitro cytotoxicity studies of quercetin-loaded mixed nanomicelles on breast cancer cells (MCF-7) revealed that, the encapsulated drug have a lower IC50 value (8.9 µg/mL) compared to the free drug (49.2 µg/mL). Our results suggest that, quercetin-loaded mixed nanomicelles can be considered as a promising drug delivery system with prolonged release and potentiated cytotoxicity against breast cancer cells.