What happens to blood within the body’s narrow capillary vessels is not fully understood, but knowing more how blood cells and plasma propagate through all sorts of vessels may help us understand and treat a number of cardiovascular diseases. To help advance knowledge in this field, researchers at the University of Birmingham in the U.K. have developed gold nanoparticles that can be tracked as they travel along with blood through the tiniest arteries and veins.
Previous attempts at using optical methods to track blood flow through capillaries have been limited because some of the components of blood, such as proteins and red blood cells, make things hard to see at such a scale. Red blood cells, for example, can be used as tracking probes by staining them, but because they’re often as wide as the vessels they pass through, they don’t provide the wanted optical resolution to get a sense of everything else that’s moving through a capillary.
The Birmingham researchers synthesized iridium-coated gold nanoparticles, which are much smaller (less than 100 nanometers) than red blood cells, that luminesce within the visible spectrum and can be spotted using optical techniques. Additionally, the nanoparticles have long lives and therefore can be tracked for extended time periods.
“The size of 100 nanometres is ideal for not disturbing the flow, yet still being detectable by high resolution imaging using conventional microscopes,” said U of Birmingham’s Professor Gerard Nash, who was one of the researchers that developed the new nanoparticles. “These nanoparticles can be used as trackers for detection in sub-millimeter channels of dimensions similar to many microvessels with higher resolution than fluorescently-stained blood cells.”
It is hoped that this research will help improve our understanding of blood clots, vascular inflammation, and improve how we fight tumors.
Here’s a quick video showing gold nanoparticles traveling along with blood flow:
Study in journal Nanomedicine: Tailoring iridium luminescence and gold nanoparticle size for imaging of microvascular blood flow…