Enhancement of thermal damage to EpCAM-positive tumor cells by novel aptamer-guided magnetic nanoparticles

Abstract

Objective: To explore the thermal damage to epithelial cell adhesion molecule(EpCAM)-positive tumor cells by novel aptamer-guided magnetic nanoparticles(AptNPs). Methods: EpCAM aptamer SYL3C was connected to NPs via biotin-streptavidin reaction. The diameter of AptNPs were characterized by Dynamic Light Scattering(DLS). The binding feature of the aptamer to EpCAM-positive tumor cells was evaluated by Prussian blue dyeing. Thermal damage under alternative magnetic field was measured bylactate dehydrogenase (LDH). The apoptosis of EpCAM-positive tumor cells was detected by acridine orange/ethidium bromide (AO/EB) double staining. Results: The average size of AptNPs was 282 nm. Flow cytometry and Prussian blue dyeing showed that AptNPs exhibited strong binding to the EpCAM-positive tumor cells but not to the EpCAM-negative tumor cells. Moreover, when incubated with 1.5×10(8) AptNPs under alternative electromagnetic fieldfor 5 hours, the viability of EpCAM-positive HCT116 cells and A549 cells was 28.9% and 54.4%, respectively, significantly lower than 76.7% of EpCAM-negative HepG2 cells (P<0.05). Conclusions: AptNPs can improve the thermal damage to EpCAM-positive tumor cells, and may have potential utility in the development of tumor targeted therapy.