Nano tool studies cystic fibrosis

Researchers are using a multi-functional sensing tool which employs nanotechnology to investigate adenosine triphosphate (ATP) release and its role in cystic fibrosis. The ATP study marks the first application of the sensing system developed by a research team led by Christine Kranz at the

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This patented technology adds recessed micro- and nano-electrodes to the tip of an atomic force microscope (AFM), creating a single tool that can simultaneously monitor topography along with electrochemical activity at the cell surface.

The new multi-functional imaging technique will advance the study of biological samples, said Boris Mizaikoff, an associate professor at Georgia Tech's School of Chemistry and Biochemistry and director of its Applied Sensors Lab.

"Conventional AFM can image surfaces, but usually provides limited chemical information," he said. "And though scanning electrochemical microscopy (SECM), another probing technique, provides laterally resolved electrochemical data, it has limited spatial resolution. By combining AFM and SECM functionality into a single scanning probe, our tool provides researchers with a more holistic view of activities at the cell surface."

In the ATP study, the Georgia Tech team used the multi-scanning biosensors to study ATP release at the surface of live epithelial cells (cells that cover most glands and organs in the body). ATP, a chemical involved in energy transport, is of interest to medical researchers because elevated levels have been linked with cystic fibrosis, a disease that affects one out of every 2,500 people in the United States.

Using epithelial cell cultures, the Georgia Tech researchers have demonstrated that their multi-functional biosensors work at the live-cell surface during in vitro studies.

"Before you can identify what triggers the ATP release, we must be able to quantitatively measure the released species at the cell surface," Mizaikoff said. He added that many pathological events involve the disruption of chemical communication and molecular signalling between cells, especially in the nervous system, lungs and kidneys.

Improved understanding of cellular communication can lead to new strategies for treating diseases. Mizaikoff said, "Being able to operate sensors in an electrochemical imaging mode at the micro- and nanoscale is an exciting opportunity for complementing optical imaging techniques. There are many clinical research problems that these biosensors can help with."

"There are a lot of emerging sensor technologies, but few have been adapted for routine use in medical research, which is one of the development goals at the Applied Sensors Lab," Mizaikoff said. "As analytical chemists, we want to develop quantitative sensing devices that can answer important questions for clinical researchers."