As we age, our arteries accumulate atherosclerotic lesions or fatty plaques. These plaques obstruct blood vessels, stiffen the artery walls, and increase the risk of ischemia, angina, stroke and heart attacks.
Plaque growth is driven by immune cells called monocytes and macrophages. These cells enter the lining of the blood vessel in response to damage, but are unable to break down the oxidised lipoproteins within the plaque. This eventually results in them becoming foam cells: highly inflammatory cells that cause further damage to the blood vessel, and eventually undergo apoptosis (cell suicide).
Attempts have been made to slow or halt plaque growth by targeting inflammation. Unfortunately, these treatments have been hampered by their unwanted effects, such as increasing susceptibility to infection. However, a study publshed in Nature Nanotechnology has suggested a potential solution to this problem. They developped a nanoparticle that targets monocytes and macrophages with high specificity. Once inside the cell, these nanoparticles deliver a compound that stimulates the macrophages to remove cellular debris from the plaque.
Importantly, this approach was able to reduce the plaque burden in mouse models without serious adverse effects. There is therefore hope that this approach could succeed in human trials where others have failed. This would represent a step forward towards the ultimate goal: to eventually develop a combination of treatments that would reverse the pathology of atherosclerosis altogether.
“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 said. “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.”https://msutoday.msu.edu/news/2020/nanoparticle-chomps-away-plaques-that-cause-heart-attacks/
Pro-efferocytic nanoparticles are specifically taken up by lesional macrophages and prevent atherosclerosis: https://doi.org/10.1038/s41565-019-0619-3
Inflammation in atherosclerosis: https://doi.org/10.1038/nature01323
NANOPARTICLE CHOMPS AWAY PLAQUES THAT CAUSE HEART ATTACKS: https://msutoday.msu.edu/news/2020/nanoparticle-chomps-away-plaques-that-cause-heart-attacks/