New tech safely delivers chemotherapy inside cancer cells

Scientists have developed an innovative new cancer-fighting technique that can carry chemotherapy medication safely and release it inside tumour cells without harming the healthy ones.
In the technique, custom-designed nanoparticles carry chemotherapy drugs directly to cancer cells and release their cargo when triggered by a two-photon laser in the infrared red wavelength.
Light-activated drug delivery technique developed by University of California - Los Angeles (UCLA) holds promise for treating cancer because it give doctors control over precisely when and where in the body drugs are 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.

Jeffrey Zink, Fuyu Tamanoi and colleagues developed a new type of nanoparticle that can absorb energy from tissue-penetrating light.
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.
The operation of the nanoparticles was demonstrated in the laboratory using human breast cancer cells.
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, researchers said.

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, researchers said.
The study was published in the journal Small.