London, March 8 (ANI): MIT chemical engineers have developed a new sensor array that can detect single molecules of hydrogen peroxide emanating from a single living cell.
Hydrogen peroxide damages cells and their DNA, but scientists have recently found new evidence that suggests it acts as a signalling molecule in a critical cell pathway that stimulates growth, among other functions.
According to the leader of the research team Michael Strano, when that pathway is skewed, cells can become cancerous, so understanding hydrogen peroxide's role could lead to new targets for potential cancer drugs.trano and his colleagues used the array, made of carbon nanotubes, to study the flux of hydrogen peroxide that occurs when a common growth factor called EGF activates its target, a receptor known as EGFR, located on cell surfaces. For the first time, the team demonstrated that hydrogen peroxide levels more than double when EGFR is activated.
EGF and other growth factors induce cells to grow or divide through a complex cascade of reactions inside the cell. It's still not understood fully how hydrogen peroxide affects this process, but Strano believes it may somehow amplify the EGFR signal, reinforcing the message to the cell. Because hydrogen peroxide is a small molecule that doesn't diffuse far (about 200 nanometers), the signal would be limited to the cell where it was produced.
The researchers also discovered that in skin cancer cells, believed to have overactive EGFR activity, the hydrogen peroxide flux was 10 times greater than in normal cells. Because of that dramatic difference, Strano believes this technology could be useful in building diagnostic devices for some types of cancer.
He said: "You could envision a small handheld device, for example, which your doctor could point at some tissue in a minimally invasive manner and tell if this pathway is corrupted."
Strano said this is the first time an array of sensors with single-molecule specificity has ever been demonstrated. He and his team derived mathematically that such an array can distinguish "near field" molecular generation from that which takes place far from the sensor surface.
Strano said: "Arrays of this type have the ability to distinguish, for example, if single molecules are coming from an enzyme located on the cell surface, or from deep within the cell."
The research has appeared in the March 7 online edition of Nature Nanotechnology. (ANI)
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