Combined nanomedicines targeting colorectal cancer stem cells and cancer cells

Abstract

The study aims to combine the delivery of two anticancer drugs to target both proliferating cancer cells and dormant cancer stem cells (CSCs) present in colorectal cancer. Two drugs were selected and encapsulated in lipid nanocapsules: SN38, the active form of irinotecan, which is unstable in the plasma but active against replicating cells, and salinomycin, a highly toxic ionophore active against cancer stem cells that is not suitable for clinical use. Using an engineered medium that enhanced the ratio of CSCs in HCT116 cell cultures, we demonstrated by clonogenicity tests and in sphere assays that Salinomycin acts mainly on CSCs, while SN38 acts mainly on proliferating cancer cells. In a preclinical murine CRC model, encapsulation of both drugs in lipid nanocapsules reduced their toxicity, including hemolysis, and led to a higher survival than what was observed following treatment with single drugs or non-encapsulated drugs. Nanoparticles loaded with an anticancer drug and salinomycin were effective against the therapy-resistant dormant CSCs and cancer cells.

Keywords: Cancer stem cells; Colorectal cancer; Lipid nanocapsules; SN38; Salinomycin.