Exosomes, discovered in the 1980s, are tiny vesicles produced by most, if not all, cells in the body. Originally thought of as a way for cells to dispose of trash that builds up within them, it has since been elucidated that exosomes are also involved in cell signaling, coagulation, and perhaps many other processes. Because cancer cells release exosomes just like other cells, being able to spot and analyze them can turn out to be an excellent way of detecting the presence of cancer at its early stages. Yet, it has proven difficult to isolate exosomes from bodily fluids and to study them up close. Now researchers at University of Kansas have developed a microfluidic device that can isolate exosomes from blood plasma much faster and easier than before.
The system relies on microscopic magnetic beads that are coated with an antibody that sticks to a protein present on the surface of exosomes. Using a magnet within the microfluidic device, the beads and the exosomes that they are attached to can be pulled away from the rest of the sample.
From the study abstract in Lab on a Chip:
Using this device, we demonstrated phenotyping of exosome subpopulations by targeting a panel of common exosomal and tumor-specific markers and multiparameter analyses of intravesicular biomarkers in the selected subpopulation. We were able to assess the total expression and phosphorylation levels of IGF-1R in non-small-cell lung cancer patients by probing plasma exosomes as a non-invasive alternative to conventional tissue biopsy. We foresee that the microfluidic exosome analysis platform will form the basis for critically needed infrastructures for advancing the biology and clinical utilization of exosomes.