Nanoparticle helps eat away deadly arterial plaque

As many readers will already know, atherosclerotic plaque-deposits on the inner walls of arteries are a frequent cause of heart attacks and strokes. A newly-developed nanoparticle could help minimize those deposits, as it prompts the body's own cells to "eat" them.

Developed via a collaboration between scientists at Michigan State University and Stanford University, the nanoparticle contains single-walled carbon nanotubes that are loaded with a drug known as an SHP1 inhibitor. The idea is that a solution containing the nanoparticles will be introduced to a patient intravenously, proceeding to flow through their bloodstream.

Once the nanoparticles encounter a plaque deposit, they act upon immune cells inside of it, known as macrophages – they are a type of white blood cell that specializes in engulfing and destroying pathogens such as bacteria and viruses.

The drug contained in the nanotubes works by inhibiting the SHP1 signalling pathway within the macrophages. Ordinarily, that pathway stops the cells from consuming apoptotic (dead) cells and cell debris, which make up the core of plaque deposits. With the SHP1 temporarily shut off, however, the macrophages are free to chow down on the stuff.

Heart attacks and strokes typically occur when one of the cores ruptures, with the resulting plaque detritus clogging the artery and blocking the blood flow to the heart or brain. When that core has been eaten, though, what remains of the deposit is smaller, more stable, and unlikely to rupture.

Additionally, unlike some other other experimental plaque-reduction treatments that harm healthy tissue, the nanoparticles only clear out dead cell material. This means that little if any unwanted side effects should occur. In fact, the therapy has already been successfully trialled on mice.

"We demonstrated the nanomaterials were able to selectively seek out and deliver a message to the very cells needed," says Michigan State's Assoc. Prof. Bryan Smith. "It gives a particular energy to our future work, which will include clinical translation of these nanomaterials using large animal models and human tissue tests."

A paper on the research was recently published in the journal Nature Nanotechnology.

Source: Michigan State University

January 28, 2020

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