Nanotech News

October 24, 2005

Nanotube Nanobomb Kills Breast Cancer Cells

The war on cancer has a new potential weapon – a carbon nanotube nanobomb that literally blows apart a cancer cell from the inside out. Light activates this novel therapeutic and cells not targeted by the nanobombs are not damaged by the localized explosions.

Reporting its work in an upcoming issue of the journal NanoBiotechnology, a research team headed by Balaji Panchapakesan, Ph.D., of the University of Delaware, and Eric Wickstrom, Ph.D., of the Kimmel Cancer Center at Thomas Jefferson University, describes how their work aimed at using carbon nanotubes as drug delivery devices surreptitiously led to their discovery of nanobombs. "We were experimenting with the molecules and considering optical and thermal properties, and found we could trigger microscopic explosions of nanotubes in wide variety of conditions,” explained Panchapakesan.

He added that the nanobombs are just that, tiny bombs on the nanoscale. "They work almost like cluster bombs," he said. "Once they are exposed to light and the resulting heat, they start exploding one after another."

The bombs are created by bundling the carbon nanotubes. With a single nanotube, the heat generated by the light is dissipated by surrounding air. In bundles, the heat cannot dissipate as quickly and the result is an explosion on the nanoscale.

When the researchers observed the explosions, they realized it might be possible to use the microscopic bombs to kill cancer cells. They recreated the explosions in solutions including water, phosphate and salt, which meant the nanobombs could be used in the human body. In fact the explosions were more dramatic in the saline solutions, Panchapakesan said. When the nanotube bundles were physically placed on clusters of cultured breast cancer cells and then illuminated with laser light, the cells were destroyed. Future work will focus on adding tumor-targeting molecules to the nanobomb.

Panchapakesan believes the nanobomb holds great promise as a therapeutic agent for killing cancer cells, with particular emphasis on breast cancer cells, because its shockwave kills the cancerous cells as well as the small blood vessels that nourish the diseased cells. Once the nanobombs are exploded and kill cancer cells, macrophages can effectively clear the cell debris and the exploded nanotube along with it.

Panchapakesan noted the team's findings are the result of interdisciplinary research. "Different sciences come together to make this work," he said, citing cancer biology, physics, electrical and computer engineering, and chemistry.

This work is detailed in a paper titled, “Single-wall carbon nanotube nanobomb agents for killing breast cancer cells.” This paper will appear in the next issue of the journal. An abstract was not yet available.