Nanoparticle eats away plaque that causes heart attacks

Michigan State University and Stanford University scientists have invented a nanoparticle that eats away—from the inside out—portions of plaques that cause heart attacks. 

Atherosclerosis is a cardiac-based disease where plaque builds up inside the body’s arteries, the blood vessels responsible for carrying oxygen-rich blood to the heart and other organs of the body. Plaque is made up of white immune blood cells, known as macrophages, fat, cholesterol, calcium, and other substances found in the blood. As this plaque hardens it narrows the arteries, limiting the flow of oxygen-rich blood around the body. This, in turn, can lead to serious problems, including heart attack, stroke, or even death.

The team states their nanoparticle reduces and stabilizes plaque, providing a potential treatment for atherosclerosis, a leading cause of death in the United States. The study is published in the journal Nature Nanotechnology.

Macrophages are a type of white blood cell in our immune system, which engulf and digest cellular debris, foreign substances, microbes, cancer cells, and anything else that does not have the type of proteins specific to healthy body cells.

Once inside the macrophages of arterial plaques, the nanoparticle delivers a drug agent that can stimulate the cell to engulf and eat cellular debris, removing the diseased/dead cells. By reinvigorating the macrophages, plaque size is reduced.

Future clinical trials on the nanoparticle are expected to reduce the risk of most types of heart attacks, with minimal side effects due to the unprecedented selectivity of the nanodrug, according to Smith. His research is focused on intercepting the signaling of the receptors in macrophages and sending a message via small molecules using Nano-immunotherapeutic platforms. Previous studies have acted on the surface of the cells, but this new approach works intracellularly and has been effective in stimulating macrophages.

"We found we could stimulate the macrophages to selectively eat dead and dying cells – these inflammatory cells are precursor cells to atherosclerosis – that are part of the cause of heart attacks," Smith said. "We could deliver a small molecule inside the macrophages to tell them to begin eating again."

This approach also has applications beyond atherosclerosis, he added.

"We were able to marry a groundbreaking finding in atherosclerosis by our collaborators with the state-of-the-art selectivity and delivery capabilities of our advanced nanomaterial platform," explained Smith. "We demonstrated the nanomaterials were able to selectively seek out and deliver a message to the very cells needed. 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. We believe it is better than previous methods."

Smith has filed a provisional patent and will begin marketing it later this year.

Thanks https://www.sciencenews.org/article/nanoparticles-beat-back-atherosclerosis https://phys.org/news/2020-01-nanoparticle-chomps-plaques-heart.html,https://www.nhlbi.nih.gov/news/2020/plaque-eating-nanoparticles-may-help-prevent-heart-attacks