Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Tissue-engineered cells transmit electrical signals in animal hearts


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:

More articles from Health and Medicine:

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

nachricht Researchers identify key step in viral replication
13.03.2018 | University of Pittsburgh Schools of the Health Sciences

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: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
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

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>