Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tissue-engineered cells transmit electrical signals in animal hearts

18.11.2002


American Heart Association meeting report



Preliminary findings of a study in rats suggests that a person’s own cells might one day replace artificial pacemakers, researchers reported today at the American Heart Association’s Scientific Sessions 2002.

Studies conducted at Children’s Hospital Boston tested the ability of immature skeletal muscle cells to interconnect with heart cells and spread the electrical impulses that keep the heart beating properly.


"The cells have survived in rats for more than a year and they appear to have made connections with cardiac cells," says Douglas B. Cowan, Ph.D., a cell biologist who led the study. "The electrical pathway developed within 10 weeks of implantation.

"Ultimately – maybe a decade down the road – we may be able to use such cell-based technologies in humans to free them from cardiac pacemaker devices," says Cowan, also an assistant professor of anesthesia at Harvard University Medical School in Boston.

Heart contraction starts with an electrical signal that begins in the atrium, a tiny area of the heart’s upper-right chamber. The signal then moves to the other chambers. Damage to the electrical pathway between the atrium and ventricles (the lower chambers) can result in complete heart block, a potentially fatal condition that can only be treated by implanting a cardiac pacemaker.

"We have gathered preliminary evidence that immature skeletal muscle cells can establish a pathway to transmit electrical signals from the heart’s upper right chamber to its lower right chamber," he says.

Heart block is present in about one in 22,000 births, Cowan says. It also can result from open-heart surgery in children, or develop later in life. It’s particularly difficult to treat in infants and children, he says.

"You can’t feed pacemaker wires through the blood vessels of some pediatric patients because the vessels are too small," he explains.

The wire must be coiled inside the chest so it can expand as the child grows, and the pacemakers or their wires often fail, which results in further surgery.

"These patients usually face several repair or replacement operations over the course of their lives," Cowan says.

Researchers extracted small amounts of skeletal muscle from the rats to obtain myoblasts, immature cells destined to become muscle. Unlike mature skeletal muscle cells, myoblasts can make the same proteins that heart muscle cells use to connect with one another to transmit electrical signals. The team used engineered tissue containing about 70 percent myoblasts and 30 percent other cell types, using the connective tissue called collagen. Tissue engineering involves removing cells from the body, manipulating them in the laboratory to create a specific tissue, such as a piece of bone for reconstructive surgery, and implanting it into the patient.

The team created three-dimensional strips of tissue by growing the cell mixtures in small tubes cut in half lengthwise. They then surgically implanted the strips in rat hearts.

"We used a general shape and cells from other animals, but the idea is that eventually we could custom grow tissue for a person using his or her own cells," Cowan notes. By using the patients’ own cells, clinicians may avoid the risk that the immune system will attack the implanted cells, he says.

"The biggest theoretical weakness in this idea was that the proteins required to connect one heart cell to another – called connexins – are usually not expressed in mature skeletal muscle," Cowan says. "Connexins are very important to conduction in the heart. They modify the speed and direction of the electrical signals, and greatly influence how they flow from cell to cell."

"The other question was whether these cells would actually connect with cardiac cells to form an electrical pathway," he says.

Today, the research team reported that the pathway developed and the connexins were present and functioning in the implanted tissue more than one year later.

"We are now using much more sophisticated measurements to confirm this phenomenon and everything at this point shows that the electrical pathway is there," Cowan says.

A lot of work remains before researchers can test the cell-implant technique in humans, Cowan says. "We need rigorous, state-of-the-art experiments to confirm that the tissue is functioning and that the same thing can happen in larger animals."


Co-authors are Yeong-Hoon Choi, M.D.; Christof Stamm, M.D.; Mara Jones, M.S.; Francis X. McGowan, Jr., M.D.; and Pedro J. del Nido, M.D.

Carole Bullock | EurekAlert!
Further information:
http://www.americanheart.org/

More articles from Health and Medicine:

nachricht New study points the way to therapy for rare cancer that targets the young
22.11.2017 | Rockefeller University

nachricht Penn study identifies new malaria parasites in wild bonobos
21.11.2017 | University of Pennsylvania School of Medicine

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: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>