In a preliminary "proof of concept" study in rabbits, Johns Hopkins scientists safely and successfully delivered therapeutic stem cells via intramuscular injections and then monitored the stem cells' viability once they reached their targets.
A report of the study by Johns Hopkins radiologists is scheduled for presentation at the Society of Interventional Radiology's 34th annual scientific meeting March 10.
Stem cells hold promise in treating PAD by reconstituting or increasing the number of blood vessels to replace or augment those choked off by plaque buildup. A chronic condition that can lead to amputations and even death, PAD is marked by vastly reduced circulation of blood in vessels feeding the legs and other "peripheral" body parts, and affects as many as 10 million Americans. Many cases can be treated with angioplasty or stents, similar to approaches used in coronary artery disease, but for some patients with extensive disease conventional treatment is not feasible, researchers say.
Among the technical hurdles to improving blood flow in such patients, according to Dara L. Kraitchman, V.M.D., Ph.D., associate professor of radiology at Johns Hopkins, is a means of telling doctors whether injected stem cells are staying alive and reaching the right targets to grow and develop into the needed new tissue.
This is critical, Kraitchman says, because the body's own immune defenses may recognize the potentially helpful donor stem cells as foreign invaders and try to destroy them, and also because traditional radioactive labeling agents, or tracers, which are normally used to track cells, can be toxic to stem cells.
To overcome rejection of the stem cells by the body's immune system — in this case, rabbit immune systems — they first created a novel "capsule" derived from seaweed, which was used to surround and protect the rabbit stem cells from attack by the host's immune system. Within the seaweed capsule, they added X-ray contrast agents to allow the capsules to be seen on X-ray angiography. Next, they engineered the stem cells within the capsules to produce luciferase, the same bioluminescent chemical produced by fireflies, which is highly visible under bioluminescence imaging.
"Once we were able to trick the immune system into not attacking the cells, we had to know they arrived at their destination and were living," says Kraitchman. "We could use standard X-ray angiography of blood vessels to see the transplanted cells. When they lit up like fireflies at night, we knew they were still alive."
"Hopefully, this new technology will one day pave the way for treating humans," says Frank Wacker, M.D., director of vascular interventional radiology at Hopkins and visiting professor of radiology. "We look to the day when we will be able to perform targeted delivery of stem cell to treat PAD in patients who may be facing amputation or death."
Gary Stephenson | EurekAlert!
Further reports about: > Hopkins > PAD > Stents > X-ray angiography > X-ray microscopy > angioplasty > arterial disease > blood vessel > fireflies > immune system > intramuscular injections > peripheral artery disease > radioactive labeling agents > seaweed > stem cell treatment > stem cells > transplanted stem cells
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research