Lactoferrin-tagged quantum dots-based theranostic nanocapsules for combined COX-2 inhibitor/herbal therapy of breast cancer

Herein, tumor-targeted quantum dots (QDs)-based theranostic nanocapsules (NCs) coloaded with celecoxib and honokiol were developed. The anionic CD44-targeting chondroitin sulfate and cationic low density lipoprotein (LDL)-targeting lactoferrin (LF) were sequentially assembled onto the surface of the positively charged oily core. As an imaging probe, highly fluorescent mercaptopropionic acid-capped cadmium telluride QDs were coupled to LF. , fluorescence of QDs was quenched (OFF state) due to combined electron/energy transfer-mediated processes involving LF. After intracellular uptake of NCs, fluorescence was restored (ON state), thus enabled tracing their internalization. The NCs demonstrated enhanced cytotoxicity against breast cancer cells as well as superior antitumor efficacy. We propose these multifunctional nanotheranostics for imaging and targeted therapy of breast cancer.