Light-activated nanoparticle cancer drug delivery dazzles

A novel theranostics technique uses dual infrared photon laser beams to release chemotherapy within tumor cells for next-generation imaging biomarker and targeted therapy, according to an announcement from the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles (UCLA).

Researchers including Jeffrey Zink, PhD, professor of biochemistry at UCLA, published the results of their breast cancer study in the April 9 issue of Small. The silica nanoparticles used in the study were dosed with a chemodrug locked in until released by the photon beams.

“Mesoporous silica nanoparticles (MSN) are functionalized in the walls with an original fluorophore with a high two-photon absorption cross-section,” wrote Zink et al. “…After incubation of the nanosystem with MCF-7 breast cancer cells, two-photon irradiation at low power is used to image the cells. At high power, cancer cell killing is observed due to the two-photon-triggered opening of the pores through [fluorescence resonance energy transfer (FRET)] and the release of the anticancer drug from the MSN.”

This technique harnesses both spatial and temporal control of the nano-drug delivery system for significantly less collateral tissue damage. The particles’ nanovalves control the release of the chemotherapy housed within thousands of chambers “like a cork in a bottle.”

The lasers’ range reaches a four centimeter depth inside the body, rendering this therapy useful for ovarian, stomach, colon and breast cancers, all of which can be monitored with fluorescence imaging.