You can see a video of how plaque forms here:
Inflammation In Atherosclerotic Plaque Formation
www.biosciencetechnology.com/news/2015/01/nanoparticle-lights-artery-clogging-plaque-be-evaluated?
The Food and Drug Administration (FDA) has approved for evaluating in people a nanoparticle-based imaging agent jointly developed at Washington University School of Medicine in St. Louis and the University of California, Santa Barbara, in collaboration with Texas A&M University. The imaging agent may illuminate dangerous plaque in arteries, and doctors hope to use it to identify patients at high risk of stroke.
“This is the first receptor-targeted nanoparticle agent for
cardiovascular imaging approved for investigational use in humans,” said
principal investigator Pamela K. Woodard, MD, professor of radiology
and of biomedical engineering. “Starting with bench research, then
developing and testing the agent and taking it through the FDA process
into human patients has involved an extensive team of basic scientists,
clinical researchers and clinicians.”
In patients with atherosclerosis, plaque accumulates on the inner walls of arteries that deliver blood to the body.
“Plaque is a complex structure, made up of cholesterol, calcified
deposits and other substances, all of which can cause inflammation,”
said Woodard, also director of the Center for Clinical Imaging Research
at the Mallinckrodt Institute of Radiology at Washington University.
“Depending on the severity of the inflammation, these plaques can be
stable or progress to a vulnerable phase in which they rupture, leading
to stroke or heart attack.”
According to Woodard, many studies have indicated that most
patients with plaque narrowing a carotid artery won’t go on to have a
stroke.
“With current technology — such as ultrasound — we can’t tell
whether the plaque is vulnerable or stable,” she said. “So we can’t
distinguish the high-risk patients who need surgery from low-risk
patients who can be treated with medication alone. We designed this
nanoparticle agent to develop a test that can detect these vulnerable
plaques and identify those patients at highest risk of stroke and in
need of surgery to remove the plaque.”
This nanoparticle agent illuminates plaque in any of the body’s
arteries and can be detected with a standard imaging technique called a
positron emission tomography (PET) scan. Researchers recently began
testing the safety of the nanoparticle in healthy individuals. They next
will focus on patients with atherosclerosis who already are scheduled
to undergo surgery to remove plaque from their carotid arteries.
“In this way, we’ll be able to see whether the areas that light up
in the image because of our nanoparticles are the same areas that
contain vulnerable plaque, as assessed from the surgeries,” Woodard
said. “Once we show success imaging the carotid arteries, we will
evaluate the nanoparticle agent in other vessels such as the coronary
arteries, which represent a greater challenge because of their smaller
size and complex motion.”
The nanoparticle is unique in how it is targeted, according to
Yongjian Liu, PhD, assistant professor of radiology and co-investigator
on the project. Previous research demonstrated that a receptor called
NPR-C is present on the surface of cells that line blood vessels and is
increased in atherosclerotic plaque. So the investigators added a small
molecule to the nanoparticle that seeks out and binds to NPR-C,
specifically targeting the particle to potentially dangerous plaque.
The nanoparticle also carries copper atoms, making it visible with a
standard PET scanner. Similar small amounts of copper-64 regularly are
used in PET scans, a technique common in cancer detection and therapy
and neurologic imaging.
In addition, components of the nanoparticle also are designed to self-assemble in the watery environment of blood.
“The success of this nanoparticle system relies on the controlled
self-assembly of functional polymers in water, which is driven by the
careful design of hydrophilic (water-attracting) and hydrophobic
(water-repelling) segments into the polymers,” said Craig J. Hawker,
PhD, professor and director of the California Nanosystems Institute at
the University of California, Santa Barbara.
Added Woodard: “We have been able to develop this highly
receptor-specific imaging technology because of the generous support
from the National Heart, Lung and Blood Institute, our diverse and
dedicated team of investigators and our extensive facilities that allow
us to make this nanoparticle imaging agent in a sterile environment,
meeting the FDA requirements for use in people.”
According to the university’s Office of Technology Management,
Pamela K. Woodard, Geoffrey E. Woodard, Rafaella Rossin and the late
Michael J. Welch are the inventors of the patented NPR-C imaging method.
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