‘CSI’ technology holds potential in everyday medicine

August 22, 2012

Part of a human brain imaged with DESI-mass spectrometry. DESI and PaperSpray mass spectrometers can help cancer physicians analyze tumors and medication levels (credit: R. Graham Cooks, Ph.D., Purdue University; Livia Eberlin, Ph.D., Purdue University; Nathalie Agar, Ph.D., Harvard Medical School; Dr. David Bennett, Rush University; and Dr. Philip De Jager, Harvard Medical School)

A scientific instrument featured on CSI and CSI: Miami for instant fingerprint analysis is forging another life in real-world medicine, helping during brain surgery and ensuring that cancer patients get effective doses of chemotherapy, said Purdue University scientist Graham Cooks at the annual American Chemical Society national meeting.

The technology is already incorporated into instruments that miniaturize room-size lab instrumentation into devices the size of a shoebox.

“With both of the instruments we developed, no sample preparation is needed, which reduces analysis time from as much as several hours per sample to just a few seconds,” said Cooks, Ph.D., who led the research team.

“Rapid results are critical when a surgeon is operating on a brain tumor or when chemotherapy patients are being treated with powerful drugs that must be administered at precise levels.”

Speeding up surgery

The instrument, called a “desorption electrospray ionization” mass spectrometer, or DESI, was featured on both CSI and CSI: Miami as a tool to analyze fingerprints. Now, Cooks’ team at Purdue University is teaming up with collaborators at Harvard University to test the instrument in the operating room during brain cancer surgery, comparing it with traditional analysis of tissue samples by pathologists.

“These procedures are among the longest of all surgical operations, and this new technology offers the promise of reducing the time patients are under anesthesia,” Cooks explained. “DESI can analyze tissue samples and help determine the type of brain cancer, the stage and the concentration of tumor cells. It also can help surgeons identify the margins of the tumor to assure that they remove as much of the tumor as possible. These are early days, but the analysis looks promising.”

The other instrument under development in Cooks’ lab is a “PaperSpray ionization” mass spectrometer. The researchers are using this new device to monitor the levels of chemotherapy drugs in patients’ blood in real time. “Many cancer drugs have relatively narrow therapeutic ranges, so they need to be in the blood at certain levels to work properly,” he noted. “But at present, that information is not obtained in real time, so a patient could end up with too little or too much of the drug in his or her body.”

Both the DESI and PaperSpray mass spectrometers work in a similar way. To weigh chemicals, mass spectrometers need to ionize, or give a positive or negative charge to a substance. Mass spectrometers usually do this inside the instrument under a vacuum without air.

But DESI and PaperSpray can do this so-called ionization process out in the open. This allows scientists much more flexibility. DESI and PaperSpray also can do analyses without separating out all of the chemicals in a sample first (unlike conventional instruments), which provides quick results. They are also very easy to operate. “You just point and shoot,” said Cooks.

Currently, Cooks’ team is testing to see whether DESI can provide different information compared to what pathologists can provide by looking at human tissues under a microscope. In addition, the researchers are testing PaperSpray on patients’ blood samples, though Cooks points out that the device also could measure the levels of drugs of abuse or pharmaceuticals in urine or other body fluids.

Funding was provided by the National Institutes of Health and the Institute for Biomedical Development at Purdue University.