Boronic-targeted albumin-shell oily-core nanocapsules for synergistic aromatase inhibitor/herbal breast cancer therapy

Abstract

Multi-modality strategies of albumin-mediated drug accumulation in tumor, boronate-based active tumor targeting and synergistic cancer therapy were combined together for effective treatment of breast cancer. Herein we report the development of albumin-shell oily-core nanocapsules (NCs), loaded with novel combination of hydrophobic drugs, exemestane (EXE) and hesperetin (HES), for targeted breast cancer therapy. This protein-lipid nanohybrid carrier was successfully fabricated using a simple protein-coating method based on the electrostatic adsorption of negatively charged albumin shell onto the oily core containing cationic surfactant. While EXE was directly encapsulated into the oily core, HES was pre-formulated in the form of phospholipid complex before solubilization in oily phase. In addition to albumin-mediated binding to albondin and SPARC, phenylboronic acid was chemically coupled to the albumin shell to confer additional tumor targeting. The targeted nanocarrier (TNC) demonstrated enhanced internalization into MCF-7 breast cancer cells resulting in synergistic cytotoxic activity with a combination index (CI) of 0.662 and dose reduction index (DRI) of 8.22 and 1.84 for EXE and HES, respectively. In vivo, TNC displayed superior anti-cancer activity in tumor-bearing mice compared to their non-targeted counterparts and the free drug combination. A significant reduction of both tumor volume (7-folds) and Ki67 expression (3-folds) was obtained by the targeted nanocarriers compared to positive control. Overall, the boronic-targeted albumin NCs offer a promising platform for hydrophobic drug combination against cancer therapy.