Fast Capture of Cancer Markers Will Aid in Diagnosis and Treatment

A nanoscale product of human cells that was once considered junk is now known to play an important role in intercellular communication and in many disease processes, including cancer metastasis. Researchers at Penn State have developed nanoprobes to rapidly isolate these rare markers, called extracellular vesicles (EVs), for potential development of precision cancer diagnosis and personalized anticancer treatments.

“Most cells generate and secrete extracellular vesicles,” says Siyang Zheng, associate professor of biomedical engineering and electrical engineering. “But they are difficult for us to study. They are sub-micrometer particles, so we really need an electron microscope to see them. There are many technical challenges in the isolation of nanoscale EVs that we are trying to overcome for point-of-care cancer diagnostics.”

The team’s initial challenge was to develop a method to isolate and purify EVs in blood samples that contain multiple other components. The use of liquid biopsy, or blood testing, for cancer diagnosis is a recent development that offers benefits over traditional biopsy, which requires removing a tumor or sticking a needle into a tumor to extract cancer cells. For lung cancer or brain cancers, such invasive techniques are difficult, expensive and can be painful.

“Noninvasive techniques such as liquid biopsy are preferable for not only detection and discovery, but also for monitoring treatment,” says Chandra Belani, M.D., professor of medicine at Penn State’s Milton S. Hershey Medical Center and Cancer Institute and clinical collaborator on the study.

How it works

“We invented a system of two micro/nano materials,” Zheng says. “One is a labeling probe with two lipid tails that spontaneously insert into the lipid surface of the extracellular vesicle. At the other end of the probe we have a biotin molecule that will be recognized by an avidin molecule we have attached to a magnetic bead.”

Read the full story at Penn State News: http://news.psu.edu/story/461302/2017/04/10/research/fast-capture-cancer...

Contact Prof. Zheng at sxz10@psu.edu.