Methoxy Poly(ethylene glycol)-Poly(lactide) Nanoparticles Encapsulating Quercetin Act as an Effective Anticancer Agent by Inducing Apoptosis in Breast Cancer

Purpose To overcome the therapeutic restrictions offered by hydrophobic quercetin (Qu), this study aims to synthesize MPEG-PLA encapsulated Qu nanoparticle and to evaluate their anticancer efficacy. Materials and Methods In vitro anticancer potential and apoptotic studies were done by cell cytotoxicity assay and flow cytometry, respectively. MPEG-PLA-Qu nanoparticles were evaluated for anticancer efficacy in vivo using xenograft mice model. TUNEL assay was performed to observe the frequency of apoptotic cells in vivo. Results The hydrodynamic particle size, polydispersity index, zeta potential and drug loading % of MPEG-PLA-Qu nanoparticle was 155.3 +/- 3.2 nm, 0.2 +/- 0.05, -3.14 mV and 5.3 +/- 1.1%, respectively. Also, MPEG-PLA-Qu showed sustained drug release for 10 days. In vitro results showed that MPEG-PLA-Qu could efficiently induce apoptosis in triple negative breast cancer cell line (MDA-MB-231) with higher amount of quercetin in cell lysate treated with MPEG-PLA-Qu in comparison to free quercetin. In xenograft model for breast cancer, peritumorally injected MPEG-PLA-Qu significantly inhibited the tumor growth. Moreover, TUNEL assay showed more occurrence of apoptotic cells in MPEG-PLA-Qu treated tumors compared to free quercetin at similar dose. Conclusion Our data suggest that MPEG-PLA-Qu nanoparticle can have a promising clinical potential for the treatment of breast cancer.