Biomarkers known as "exosomes" in the human body could reveal themselves to a "lab on a chip" for earlier and less invasive detection of some cancers and other diseases, improving the survival chances of patients, U.S. researchers say.
Cancer diagnostics based on exosomes have been a goal since exosomes were first understood in the 1980s, they said.
"Exosomes are minuscule membrane vesicles -- or sacs -- released from most, if not all, cell types, including cancer cells," says University of Kansas researcher Yong Zeng.
Scientists have come to understand how exosomes have significant roles in a number of biological functions, delivering molecular signals from donor cells that affect functions of other cells that are either close by or distant.
"In other words, this forms a crucial pathway in which cells talk to others," Zeng says.
Exosomes are so tiny that they are difficult to separate and gather for testing, with current methods needing long, inefficient and tedious sessions in a laboratory.
Now, Zeng along with his research colleagues, in a study published in the journal of the Royal Society of Chemistry, have described their development of a miniature biomedical test device capable of working with exosomes.
The "lab-on-a-chip," by shrinking the test tubes, pipettes and analyzing instruments found in a typical chemistry laboratory onto a small microchip wafer, can offer faster result times, better sensitivity and reduced costs compared to current methods of examining the tiny biomarkers, the researchers say.
The chip uses "microfluidic" technology developed in the 1990s and improved ever since in order to manipulate miniscule volumes of fluid. The analysis involves sample purification, biological and chemical reactions, measurement and analysis, they say.
Using just a tiny drop of a person's blood, diseases such as lung cancer, which kills people in the United States, could be detected at a much earlier stage, they suggest.
Unlike some other cancers such as colon or breast cancer, there are currently no accepted early screening tools for detecting lung cancer.
"Most lung cancers are first diagnosed based on symptoms, which indicate that the normal lung functions have been already damaged," Zeng says, noting that diagnosis requires a tumor biopsy that can fail to yield an early diagnosis because the developing tumor is often too tiny to be detected by current imaging methods.
"In contrast, our blood-based test is minimally invasive, inexpensive, and more sensitive, thus suitable for large population screening to detect early-stage tumors," Zeng says.
Because the lab-on-a-chip technology can be a general platform for detecting tumor-derived exosomes, it could be utilized to diagnose a wide range of deadly cancers, the researchers say.
