Scientists have developed a new technique to fight cancer whereby chemotherapy medication can be safely released inside tumor cells without the healthy ones being harmed.
The technique involves custom-designed nanoparticles carrying chemotherapy drugs directly to cancer cells. Their contents are released when triggered by a two-photon laser in the infrared red wavelength.
The light-activated drug delivery technique developed by the University of California - Los Angeles (UCLA) is promising for treating cancer because doctors have control over exactly when and where in the body drugs are disbursed.
This type of process has the potential to significantly reduce side effects of treatment while boosting the cancer-killing effect of the drug.
The findings come from UCLA's Jeffrey Zink, professor of chemistry and biochemistry and Fuyu Tamanoi, professor of microbiology, immunology and molecular genetics and their colleagues. They were published online Feb. 20 in the journal Small and will appear later in a print edition.
The process of developing a drug-delivery system that responds to tissue-penetrating light has been a difficult one. In order to accomplish the task, the team of Zink and Tamanoi collaborated with Jean-Olivier Durand of France's University of Montpellier to develop a new type of nanoparticle capable of absorbing energy from tissue-penetrating light.
The new nanoparticles have thousands of pores capable of holding chemotherapy drugs. Nanovalves cap the ends of the pores to keep the drugs in. Inside the nanovalves are special molecules that respond to energy from two-photon light exposure. Exposure causes the valves to open and release the drugs.
The process was demonstrated in the laboratory using human breast cancer cells. The effective range of the two-photon laser in the infrared red wavelength is four centimeters from the skin surface. According to the researchers, this means that the delivery system would work best for tumors within that range, including stomach, breast, colon and ovarian tumors.
The new nanoparticles are also fluorescent and can be monitored in the body through molecular imaging techniques. This means that researchers can track the nanoparticle into the cancer cell prior to light activation.
"We have a wonderful collaboration," Zink said. "When the Jonsson Comprehensive Cancer Center brings together totally diverse fields - in this case, a physical chemist and a cell signaling scientist - we can do things that neither one could do alone."
"Our collaboration with scientists at Charles Gerhardt Institute was important to the success of this two-photon-activated technique, which provides controls over the drug delivery to allow local treatment that dramatically reduces the side effects," Tamanoi added.
