In this work, lipid-based nanoparticles (LBNP) were designed to combine tyrosine kinase inhibitor (TKI) Lapatinib (LAPA) with siRNA directed against apoptosis inhibitor protein Survivin (siSurvivin) in an injectable form. This nanosystem is based on lipid nanocapsules (LNCs) coated with a cationic polymeric shell composed of chitosan grafted through a transacylation reaction. The hydrophobic LAPA is solubilized in the inner oily core, while hydrophilic siRNA is associated electrostatically onto the nanocarrier’s surface. The co-loaded LBNP showed a narrow size distribution (polydispersity index (PDI) < 0.3), a size of 130 nm, and a slightly positive zeta potential (+21 mV). LAPA and siRNA were loaded in LBNP at a high rate of >90% (10.6 mM) and 100% (4.6 µM), respectively. The siRNA-LAPA_LBNP was readily uptaken by the human epidermal growth factor receptor 2 overexpressed (HER2+) breast cancer cell line SK-BR-3. Moreover, the cytotoxicity studies confirmed that the blank chitosan decorated LBNP is not toxic to the cells with the tested concentrations, which correspond to LAPA concentrations from 1 to 10 µM, at different incubation times up to 96 h. Furthermore, siCtrl.-LAPA_LBNP had a more cytotoxic effect than Lapatinib salt, while siSurvivin-LAPA_LBNP had a significant synergistic cytotoxic effect compared to siCtrl.-LAPA_LBNP. All these findings suggested that the developed modified LBNP could potentiate anti-Survivin siRNA and LAPA anti-cancer activity.
Keywords: HER2+ breast cancer; Lapatinib; Survivin; co-delivery; lipid-based nanoparticles; siRNA.