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 Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

Hope to discover sure signs of life on Mars? New research says look for the element vanadium

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>