The device developed by researchers which combines acoustic cell-sorting and microfluidic technologies. The system is optimized to sort out exosomes from blood, biological nanoparticles released from every type of cell in the body.
To play a large role in cell-to-cell communication and disease transmission. They have been objects of scientific curiosity since their discovery three decades ago.
Acoustics and Microfluidics
Researchers from Duke University, the University of Pittsburgh and Magee Women Research Institute, the Massachusetts Institute of Technology and Nanyang Technological University Singapore, demonstrate a better method based on acoustofluidics, a combination of acoustics and microfluidics.
The miniscule size of exosomes makes them difficult to study and challenging to separate from their native biological fluids. Current practices involve spinning samples in a centrifuge for several hours or even days. Often damaging the exosomes by subjecting them to extremely high gravitational forces. Even then, the procedure only captures a small fraction of the nanoparticles present in the biological fluid.
The prototype device provides a gentle, automated, point-of-care system that allows single-step, on-chip isolation of exosomes from whole biological fluids with a high rate of purity and yield.
The results could help researchers and clinicians learn more about exosomes and form the foundation for diagnostic or therapeutic devices. The device may enable diagnosis and monitoring of many conditions with a simple blood draw. Including cancer liquid biopsy, concussions and diseases affecting the brain, kidney, liver and placenta. This work offers a new technique that can address these issues. We want to make extracting high-quality exosomes as simple as pushing a button. Getting the desired samples within 10 minutes.
The prototype device built by Huang and his colleagues creates a high-frequency sound wave traveling at an angle to liquid flowing down a tiny tube. By carefully tailoring the angle and frequency of the sound wave to the length of the channel and size of the particles. They can push any particle bigger than 1,000 nanometers into a separate channel.
Separation of blood cells and platelets
This removes elements of blood such as white blood cells, red blood cells and platelets. The fluid then goes through a second chamber. The same force is used to filter out everything smaller than 130 nanometers. The size of most exosomes and 500 times smaller than the thickness of the human hair.
The dual-stage technique showed the ability to separate more than 80 percent of exosomes present with a purity of 98 percent. Compared to current methods that capture only 5 to 40 percent of exosomes. The new device can eliminate all blood cells and platelets first before efficiently separating extracellular vesicles such as exosomes,” explained Ming Dao, director of the Nano mechanics Laboratory at MIT.
A new dimension to research into liquid biopsies and facilitate the clinical use of extracellular vesicles. To inform the physiology and health of organs that are hard to access, such as the placenta during human pregnancy, said Yoel Sadovsky, director of the Magee-Women Research Institute at the University of Pittsburgh.