Nanoparticle eats away at plaque in arteries

(Credit: Getty Images)

A new “Trojan Horse” nanoparticle can eat away portions of the plaques that cause heart attacks, research in mice indicates.

The discovery could be a potential treatment for atherosclerosis, a leading cause of death in the United States.

The nanoparticle homes in on atherosclerotic plaque due to its high selectivity to a particular immune cell type—monocytes and macrophages.

Once inside the macrophages in those plaques, it delivers a drug agent that stimulates the cell to engulf and eat cellular debris. Basically, it removes the diseased/dead cells in the plaque core. By reinvigorating the macrophages, it reduces and stabilizes plaque size.

An image of a atherosclerotic artery with an inset showing the nanoparticles at work stimulating macrophages
The dotted line outlines the atherosclerotic artery and the green represents the nanoparticles, which are in the plaque. The red indicates macrophages, the cell type that the nanoparticles are stimulating to eat the debris. (Credit: Michigan State)

The researchers expect future clinical trials on the nanoparticle to reduce the risk of most types of heart attacks, with minimal side effects due to the unprecedented selectivity of the nanodrug, says Bryan Smith, associate professor of biomedical engineering at Michigan State University.

Smith’s studies focus on intercepting the signaling of the receptors in the 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 says. “We could deliver a small molecule inside the macrophages to tell them to begin eating again.”

This approach also has applications beyond atherosclerosis, he adds.

“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. We demonstrated the nanomaterials were able to selectively seek out and deliver a message to the very cells needed,” Smith says.

“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.”

The research appears in Nature Nanotechnology. Additional researchers from Michigan State University and Stanford University contributed to the work.

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

Source: Michigan State University