An ultra-sensitive diagnostic device was developed that enables “liquid biopsy” analysis. The device detects exosomes — tiny parcels of biological information produced by tumor cells to stimulate tumor growth or metastasize. Exosomes send messages to recipient cells and communicate molecular information important in many biological functions. While all cells produce exosomes, tumor cells are more active compared to normal cells.
The lab-on-a-chip’s key innovation is a 3D nanoengineering method that mixes and senses biological elements based on a herringbone pattern commonly found in nature, pushing exosomes into contact with the chip’s sensing surface much more efficiently in a process called “mass transfer.” When particles move closer to the sensor surface, they are separated by a small gap of liquid that creates increasing hydrodynamic resistance. The 3D nanoporous herringbone structure can drain the liquid in that gap to bring the particles in hard contact with the surface where probes can recognize and capture them.
The chip’s design was tested using clinical samples from ovarian cancer patients; the chip could detect the presence of cancer in a minuscule amount of plasma. In addition, the microfluidic chips would be cheaper and easier to make than comparable designs, allowing for wider and less-costly testing for patients. With the microfluidic chip’s design now proven using ovarian cancer as a model, the chip could be useful in detecting neurodegenerative diseases or breast and colorectal cancers.