Sensors Monitor Chemotherapy

The sensors, made of carbon nanotubes wrapped in DNA, can detect chemotherapy drugs such as cisplatin as well as environmental toxins and free radicals that damage DNA.
"We've made a sensor that can be placed in living cells, healthy or malignant, and actually detect several different classes of molecules that damage DNA," said Michael Strano, associate professor of chemical engineering.

Such sensors could be used to monitor chemotherapy patients to ensure the drugs are effectively battling tumors. Many chemotherapy drugs are very powerful DNA disruptors and can cause serious side effects, so it is important to make sure that the drugs are reaching their intended targets.

"You could figure out not only where the drugs are, but whether a drug is active or not," said Daniel Heller, a graduate student.

The new technology takes advantage of the fact that carbon nanotubes fluoresce in near-infrared light. Human tissue does not, which makes it easier to see the nanotubes light up.

Each nanotube is coated with DNA, which binds to DNA-damaging agents present in the cell. That interaction between the DNA and DNA disruptor changes the intensity and/or wavelength of the fluorescent light emitted by the nanotube. The agents produce different signatures that can be used to identify them.

Because they are coated in DNA, these nanotube sensors are safe for injection in living cells.; Source: Massachusetts Institute of Technology