Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New therapy could treat poor blood circulation caused by peripheral artery disease


An injectable gel was tested in a rat model of critical limb ischemia

Bioengineers and physicians at the University of California, San Diego have developed a potential new therapy for critical limb ischemia, a condition that causes extremely poor circulation in the limbs and leads to an estimated 230,000 amputations every year in North America and Europe alone to prevent the spread of infection and tissue death. The new therapy could prevent or limit amputations for a condition that affects more than 27 million people and is a manifestation of advanced peripheral arterial disease.

Tissue from the skeletal muscle of pigs is spun in detergent until only the fibrous extracellular matrix remains.

Credit: Jacobs School of Engineering/UC San Diego

The therapy consists of injecting in the affected area a gel derived from the natural scaffolding, or extracellular matrix, in skeletal muscle tissue. The team tested the procedure in a rat model of the disease and found that it promotes muscle remodeling and improves blood flow. They published their findings recently in the inaugural issue of the Journal of the American College of Cardiology: Basic to Translational Science.

"This is a unique approach that not only helps repair the damaged vascular system, but also helps restore muscle tissue," said Karen Christman, a professor of bioengineering at the Jacobs School of Engineering and the Sanford Consortium for Regenerative Medicine at UC San Diego and the paper's senior author.

"Avoiding or limiting extent of amputations is a huge benefit for patients," said Dr. Ehtisham Mahmud, chief of cardiovascular medicine at the Sulpizio Cardiovascular Center at UC San Diego and a study co-investigator.

Christman and Mahmud partnered to make sure the study's design would eventually help patients when the therapy was ready for the clinic--a step that should take about two years. "This is what makes UC San Diego unique," said Mahmud. "We are bringing together engineering and medicine and demonstrating the translational implications of preclinical research."

As far as researchers know, no one had tried to use an injectable material by itself to treat both the low blood flow and weakened skeletal muscle in critical limb ischemia.

Peripheral arterial disease and critical limb ischemia

Peripheral arterial disease patients suffer from poor circulation in their limbs, which can lead to critical tissue damage. The condition is associated with atherosclerosis in old age, diabetes and smoking. It affects men and women equally. In the most extreme form, called critical limb ischemia, a severe obstruction of arteries in the limbs reduces blood flow to hands, feet and legs. Some of Mahmud's patients experience severe pain in their limbs. Some already suffer from tissue necrosis, or amputations. Others suffer from wounds that won't heal and get infected because they lack proper blood supply.

For these patients, traditional surgery or endovascular procedures can often reestablish normal blood flow. But when these interventions fail or aren't possible, limited options remain. So far, potential therapies for these patients, including using growth factor, gene or cell therapy, have proven problematic and costly. Amputations end up being a common option for treatment in severe cases of critical limb ischemia, Mahmud said.

Injectable gel therapy

Christman's team had already shown that injection of a gel derived from cardiac muscle tissue extracted from pigs could help repair the heart after a heart attack. The tissue is stripped of cells, leaving behind a scaffold of the extracellular matrix from cardiac muscle, which acts a regenerative environment where cells can grow again.

Using this same concept, Christman and her team now are turning their attention to peripheral artery disease and critical limb ischemia. They developed a material that was derived from the skeletal muscle of pigs to treat damaged skeletal muscle in these patients. Researchers injected the gel into the affected area in a rat model of the disease seven days post-surgery and monitored blood flow in the rats' limbs up to 35 days after injection.

Researchers found that the hydrogel increased the diameter of the rats' larger blood vessels, called arterioles. The increased diameter led to improved blood flow in the limbs. By day 35, the size and structure of muscle fibers in the rats treated with the hydrogel was comparable to that in healthy rats.

The gel, which forms a fibrous scaffold upon injection, also attracted muscle stem cells to the affected area. Gene expression analysis showed that inflammatory response and cell death decreased while blood vessel and muscle development pathways increased in rats injected with the gel.

Next steps include looking at other disease models in animals and refining preclinical safety protocols and quality control for manufacturing. Ventrix, a startup cofounded by Christman, partially licensed the technology from UC San Diego for clinical applications.


Jessica L. Ungerleider and Todd D. Johnson from the Department of Bioengineering at the University of California, San Diego, were co-first authors of the study. Other authors included UC San Diego bioengineers Melissa J. Hernandez, Dean I. Elhag and Rebecca L. Braden; Monika Dzieciatkowska and Kirk C. Hansen from the Department of Biochemistry and Molecular Genetics at the School of Medicine at the University of Colorado, Aurora; and Kent G. Osborn from the Animal Care Program at UC San Diego.

Funding was provided in part by the Heart, Lung and Blood Institute at the National Institutes of Health and the American Heart Association.

Media Contact

Ioana Patringenaru


Ioana Patringenaru | EurekAlert!

More articles from Health and Medicine:

nachricht Scientists develop tiny tooth-mounted sensors that can track what you eat
22.03.2018 | Tufts University

nachricht NIH scientists describe potential antibody treatment for multidrug-resistant K. pneumoniae
14.03.2018 | NIH/National Institute of Allergy and Infectious Diseases

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>