Exosomes are tiny vesicles that seemingly all the cells in our bodies produce. Initially, exosomes were thought to be a way for cells to expunge built-up trash, but over the past decade or so scientists have discovered that they seem to play an important role in regulating a variety of biochemical processes. One thing that has been discovered is that neoplasms produce a lot more exosomes than healthy cells, and that the exosomes can carry biomarkers pointing to the existence of the tumors.
Filtering out exosomes from blood, because of their extremely small size, is not easy, but it’s a focus of a number of research institutions around the world (see flashbacks below). At the University of Kansas, scientists have now developed a microfluidic device that features nano-scale patterning, which is able to pull out exosomes from blood plasma and identify whether they carry a cancer biomarker.
The nano-pattern within the device resembles a fish bone, and it’s produced via a self-assembly chemical process. The fish bone pattern selectively pushes exosomes right against an electronic chip, which senses the presence of the exosomes. This is a challenge, as any liquid will tend to encapsulate an exosome, preventing its direct contact with a surface. By leveraging the fish bone structure with a technique called mass transfer, the researchers were able to effectively pull any liquid away from the chip’s surface and allow exosomes to make a direct contact with it.
The technology was tested on blood plasma samples taken from ovarian cancer patients, as well as healthy controls. The researchers were able to spot CD24, an epithelial cell adhesion molecule, and folate receptor alpha, within the exosomes gathered from the patients. The investigators believe that folate receptor alpha may be a biomarker for ovarian cancer, and with their device it can be readily spotted.
Flashbacks: Plasmonic Biosensor to Detect Exosomes with Naked Eye…; Acoustofluidics Pulls Exosomes from Whole Blood…; Exosomes, The Elusive Tiny Vesicles Produced by Cells, Have Lots of Potential for Medicine…
Study in Nature Biomedical Engineering: Ultrasensitive detection of circulating exosomes with a 3D-nanopatterned microfluidic chip…