Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineering the heart piece by piece

29.03.2007
U-M scientists see great promise in cardiac tissue engineering, but hurdles remain before lab-grown muscle is ready for patients

Some day, heart attack survivors might have a patch of laboratory-grown muscle placed in their heart, to replace areas that died during their attack. Children born with defective heart valves might get new ones that can grow in place, rather than being replaced every few years. And people with clogged or weak blood vessels might get a new “natural” replacement, instead of a factory-made one.

These possibilities are all within reach, and could transform the way heart care is delivered, say University of Michigan Medical School researchers in the new issue of the journal Regenerative Medicine. Technology has advanced so much in recent years, they write, that scientists are closer than ever to “bioengineering” entire areas of the heart, as well as heart valves and major blood vessels.

But hurdles still remain before the products of this tissue engineering are ready to be implanted in patients as replacements for diseased or malformed structures, the team notes. Among the hurdles: determining which types of cells hold the most potential, and finding the best way to grow those cells to form viable cardiac tissue that is strong, long-lasting and structured at a cellular level like natural tissue.

... more about:
»BEHM »Birla »Laboratory »U-M »Valve »artificial »cardiac »vessel

The new article reviews the current state of cardiac tissue engineering, both at the U-M Cardiac Surgery Artificial Heart Laboratory and in labs worldwide.

“Tissue engineering is a rapidly evolving field, and cardiovascular tissue is one of the most exciting areas but also one of the most challenging,” says Ravi Birla, Ph.D., the paper’s senior author and director of the U-M Artificial Heart Laboratory. “With this paper, we’re presenting the current state of the art as it exists in our lab and others, and pointing out both potential applications and hurdles that remain.”

The paper presents a model for collaborative research between engineers, clinicians and biologists for successful cardiovascular tissue engineering research.

“Although there remain tremendous technological challenges, we are now at a point where we can engineer first-generation prototypes of all cardiovascular structures: heart muscle, tri-leaflet valves, blood vessels, cell-based cardiac pumps and tissue engineered ventricles,” says Birla.

Research at the Artificial Heart Laboratory has focused on comparing different platforms to engineer functional heart muscle in the laboratory. Last December, Birla and first author Yen-Chih Huang, PhD, published a paper describing their success in growing pulsing, three-dimensional patches of bioengineered heart muscle, or BEHM. That paper describes the use of an innovative technique, using a fibrin hydrogel, that is faster than others, but still yields tissue with significantly better properties.

The gel was able to support rat cardiac cells temporarily, before the fibrin broke down as the cells multiplied and organized into tissue within a few days. Tests showed that the BEHM was capable of generating pulsating forces and reacting to stimulation more like real muscle than ever before.

Previously, the group described the results of a self organization strategy, showing that it was possible to engineer heart muscle that closely resembles normal heart muscle physiology without any synthetic scaffolding material. The U-M team and others have also shown how polymeric scaffolds can be used to engineer heart muscle of any shape or size to match the area of the damaged heart muscle – raising the possibility of engineering customized patches to meet the specific requirements of patients. All of these approaches are described in the recent review article.

The new article, by Birla and lead author Louise Hecker, a graduate student in the U-M Department of Cell & Developmental Biology, describes the “bioreactor” that the team uses to grow their BEHM. It also details many other discoveries that have been made by other teams using different cell-growing surfaces and conditions, as well as hurdles that still lie ahead. In all, the authors say, bioengineered cardiac tissue holds immediate promise as a way to study heart disease and its treatment in cell cultures – and promise over the longer term as a source of new patient treatments.

As part of the effort to make the leap from the lab to the clinic, U-M is applying for patent protection on the Artificial Heart Laboratory’s developments and is actively looking for a corporate partner to help bring the technology to market.

The U-M team’s bioreactor was developed Robert Dennis, Ph.D., formerly of the U-M College of Engineering and now at the University of North Carolina. It allows up to 11 specimens of tissue to be grown in the same conditions at the same time, while allowing each specimen to be “stretched” using a specially made device that can both apply forces and measure the forces generated when the tissue begins contracting and beating on its own. In the new paper, the team reports that it has achieved a doubling of the contracting force in just seven days, by stretching the BEHM at 1 Hertz.

The growing of heart muscle, heart valve and blood vessel tissue in the lab also requires careful control of conditions such as temperature, oxygen and carbon dioxide levels, nutrients and pH level. This can then encourage the cells to begin producing the kinds of molecules needed to signal to and connect with other cells, and to produce the extracellular matrix that supports cells in tissue.

The U-M Artificial Heart Laboratory has teamed up with a commercial partner to develop a novel perfusion system that can deliver controlled nutrient exchange to the tissue engineered heart muscle. The perfusion system is the first of its kind, because it does not rely on a traditional cell culture incubator, giving the researchers the ability to carefully control the culture environment of the cells during heart muscle formation and foster a higher degree of functionality.

Even if cell-growing conditions can be perfected to produce tissue that is strong, durable and shaped like the native tissue it is designed to replace, another major challenge remains: which type of cells to use. Or more clearly, which types of cells to use – because heart muscle tissue is made up of several types of cells. Human heart cells are hard to come by, and “adult” stem cells haven’t yet been shown to be changeable into cardiac cells. Embryonic stem cells, while promising, come with political baggage. And other types of muscle cells taken from elsewhere in the body — including skeletal muscles — have been used in early clinical trials, but results are mixed.

Kara Gavin | EurekAlert!
Further information:
http://www.umich.edu

Further reports about: BEHM Birla Laboratory U-M Valve artificial cardiac vessel

More articles from Life Sciences:

nachricht Researchers identify how bacterium survives in oxygen-poor environments
22.11.2017 | Columbia University

nachricht Researchers discover specific tumor environment that triggers cells to metastasize
22.11.2017 | University of California - San Diego

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

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

Researchers at IST Austria define function of an enigmatic synaptic protein

22.11.2017 | Life Sciences

Fine felted nanotubes: CAU research team develops new composite material made of carbon nanotubes

22.11.2017 | Materials Sciences

Women and lung cancer – the role of sex hormones

22.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>