BME Professor Ke Cheng and postdoctoral research scholars Shiqi Hu and Zhenhua Li recently developed an exosome-coated stent with a “smart-release” trigger that could both prevent reopened blood vessels from narrowing and deliver regenerative stem cell-derived therapy to blood-starved, or ischemic, tissue.
Exosomes are tiny nano-sized sacs secreted by most cell types. The idea behind the coating was two-fold: first, since the exosomes are composed of materials not much different from cell membranes they ‘camouflage’ the stent to trick smooth muscle cells and the body’s immune system. Second, the exosomes promote coverage of the stent by endothelial cells and, in the case of injury, travel downstream to the site to promote tissue repair.
The stent releases exosomes when it encounters reactive oxygen species (ROS) – which are more prevalent during an inflammatory response. “Think of it as a smart release function for the exosomes,” says Dr. Cheng, who is also a Regenerative Medicine Professor in the Department of Molecular Biomedical Science at NC State. “Ischemic reperfusion injuries, which occur when blood flow is diminished and then reestablished, create a lot of reactive oxygen species (ROS). Let’s say the heart is damaged by ischemia. The enhanced ROS will trigger the release of the exosomes on the stent, and regenerative therapy will travel through the blood vessel to the site of the injury.” To read the full article, visit WRAL TechWire website here.