Laser-activated drug delivery boon to tackle cancer

Here comes an innovative cancer-fighting method where custom-designed nanoparticles carry and release chemotherapy drugs directly to tumour cells when triggered by a two-photon laser in the infrared red wavelength.

Light-activated drug delivery holds promise for treating cancer because it gives doctors control over precisely when and where in the body drugs are to be released.

"Delivering and releasing chemotherapy drugs so that they hit only tumour cells and not surrounding healthy tissues can greatly reduce treatment side effects and increase the drugs' cancer-killing effect," explained researchers from University of California, Los Angeles (UCLA).

These new nanoparticles are equipped with thousands of pores, or tiny tubes, that can hold chemotherapy drugs.

The ends of the pores are capped with nanovalves that keep the drugs in, like a cork in a bottle.

The nanovalves contain special molecules that respond to energy from two-photon light exposure, which prompts the valves to open and release the drugs.

"Because the effective range of the two-photon laser in the infrared red wavelength is 4 centimetres from the skin surface, this delivery system would work best for tumours within that range, which possibly include breast, stomach, colon and ovarian tumours," informed Jeffrey Zink, a professor of chemistry and biochemistry at UCLA.

In addition to their light sensitivity, the new nanoparticles are fluorescent and can be monitored in the body using molecular imaging techniques.

This allows researchers to track the progress of the nanoparticle into the targeted cancer cell before light activation, added Fuyu Tamanoi, a professor of microbiology, immunology and molecular genetics.

The research was published in the journal Small.