Bioethics Blogs

Nanoparticles Target Damaged Blood Vessels

Microscopic view of damaged vs. undamaged lamina

Caption: [A] Elastin stain (black) showing damaged elastic lamina in aorta. Inset (higher magnification) shows fluorescent nanoparticles attached to aorta where elastin is damaged. [B] Elastin stain showing aorta with undamaged elastic lamina. Inset shows no nanoparticle attachment. L stands for lumen, the open area inside the aorta.
Credit: Naren Vyavahare, Clemson University

Cardiovascular disease (CVD) is the number one killer of Americans. There are, in fact, many types of CVD—but common to most of them is damaged blood vessels. Stents can be inserted to prop open collapsed or narrowed arteries, and deliver drugs inside vessels. But, so far, we haven’t been able to repair the damaged vessels themselves. Researchers in an NIH-funded team of bioengineers at Clemson University, in South Carolina, are among those who believe that delivering drugs directly to the site of damage to mend the vessel might boost our ability to treat CVDs. And they’ve devised a way to deliver such drugs right where they want them: using specially-crafted nanoparticles.

These nanoparticles work by exploiting a common feature of CVD-damaged vessels. The middle layer of healthy blood vessels includes smooth muscle cells and the elastic lamina, rubber band-like fibers that enable vessels to dilate and constrict. In damaged vessels, fibers are fragmented, and the sugar-protein molecules that typically coat healthy elastin fibers are degraded—leaving the fibers naked. The Clemson team identified an antibody protein that recognizes the naked elastin fibers, but not the healthy, coated ones. They tethered the antibody to a biodegradable nanoparticle—just 200 nanometers in diameter (about the size of a very small microbe).

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.