Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cells from amniotic fluid used to tissue-engineer a new trachea

10.10.2005


Pediatric surgeon looks to fetal cells to repair birth defects

Researchers at Children’s Hospital Boston report using tissue engineering to reconstruct defective tracheas (windpipes) in fetal lambs, first using cells from the amniotic fluid to grow sections of cartilage tube, and then implanting these living grafts into the lambs while still in the womb.

The tracheal repair technique is one of several tissue-engineering approaches pioneered at Children’s that use the fetus’s own cells, drawn from the amniotic fluid that surrounds it, to create patches to fix birth defects -- in this case, even before birth. Pediatric surgeon Dario Fauza, MD, who led the study, will present the team’s work on OOctober 8 at the American Academy of Pediatrics annual conference in Washington, DC.



Amniotic fluid is easily collected during pregnancy and contains unspecialized cells, known as mesenchymal stem cells, that can make many of the tissues needed to perform repairs, Fauza says.

While tracheal defects are rare, they’re life-threatening: babies born with incomplete, malformed or missing tracheas cannot breathe and must immediately go on heart-lung bypass, which can cause neurologic and other complications. Surgeons have tried various fixes, such as grafting in pieces of the baby’s rib or pelvic bone, using synthetic substances like Teflon, or implanting stents (in the hope that tissue would scar around the stents and form a tube), but with limited success.

"These are all makeshift solutions, and they’re fraught with complications – infection, narrowing of the trachea, reoperation," Fauza says. Working with sheep, considered a good model for humans (lambs grow quickly and are similar in size to human babies), Fauza’s team obtained a small quantity of amniotic fluid and isolated mesenchymal stem cells. Mesenchymal stem cells descend directly from embryonic stem cells and are abundant in the amniotic fluid. They specialize in making connective tissues, including muscle, bone, cartilage, fat and tendon.

Fauza’s team multiplied the amniotic mesenchymal cells in culture, then "seeded" them onto biodegradable tubes of the needed dimensions and shape. The tubes and cells were then exposed to growth factors that caused the mesenchymal cells to differentiate into cartilage cells. When the engineered grafts were ready, they were used to reconstruct defective tracheas in seven fetal lambs. Four to five weeks later, the lambs were born, and all five lambs that survived to term were able to breathe spontaneously at birth, four of them with no sign of respiratory distress. (The other two lambs, twins, were born prematurely and did not survive.)

While many congenital defects can be safely repaired after birth, Fauza’s goal is to fix tracheal defects in utero. Once the baby is born, tracheal surgery requires that the baby be intubated and ventilated long after the operation while the trachea heals; this can lead to many complications, including failure of the repair. Fetal surgery would eliminate these interventions and their resulting problems. "The fetus doesn’t need the trachea, so the repair would have time to heal in utero," Fauza explains. "And fetal healing is very good – it’s better than adult healing."

Fauza, whose research lab works closely with Children’s Advanced Fetal Care Center, has been investigating the idea of growing new tissues and organs for these tiny patients for eight years. Since the tissue-engineered grafts are made from the baby’s own cells, taken before birth, there would be no risk of the immune system rejecting the tissues, and since fetal cells are immature and not fully specialized, they can be used to generate a variety of tissues.

Currently, most tissue engineers use adult cells to create their lab-grown tissues. While Fauza has also used cells from the ear and from the bone marrow to derive cartilage cells, amniotic fluid is much more readily available. Millions of pregnant women elect to have amniotic fluid drawn to test for chromosome defects, the procedure known as amniocentesis. And when a prenatal ultrasound exam reveals fetal malformations, amniocentesis is usually recommended. Complications are rare.

"In many cases, the amniotic fluid is collected anyway," says Fauza. "It’s a precious resource that’s thrown out now, but shouldn’t be."

Less than two tablespoons of amniotic fluid provide enough fetal cells to repair a malformation in utero or after birth – potentially, even years later, Fauza says. He envisions a future in which amniotic fluid is banked for everyone’s use. "Fetal cells are the best cells you can have for tissue engineering," he says. "They grow very well, and they’re very plastic – you can coach them to do what you want."

Last year, Fauza reported using similar techniques in newborn lambs to repair congenital diaphragmatic hernia (CDH), or a hole in the diaphragm that separates the lungs from the visceral organs. If the hole is large enough, the stomach and other visceral organs can end up in the chest cavity, crowding the lungs and stunting their growth. Using mesenchymal stem cells from amniotic fluid, Fauza’s team engineered a tendon patch for the diaphragm; a year later, the lambs’ diaphragms showed good healing.

The FDA is now reviewing Fauza’s application to conduct a clinical trial in human babies with a prenatal ultrasound diagnosis of CDH; the amniotic fluid would be collected several months before birth and a tissue-engineered patch made ready for use soon after delivery. His team is also working on stem-cell-based, tissue-engineered grafts to fix spina bifida (in which the spinal column doesn’t close fully during fetal development) and structural cardiac defects, using similar principles.

Mary-Ellen Shay | EurekAlert!
Further information:
http://www.childrenshospital.org

More articles from Life Sciences:

nachricht 'Y' a protein unicorn might matter in glaucoma
23.10.2017 | Georgia Institute of Technology

nachricht Microfluidics probe 'cholesterol' of the oil industry
23.10.2017 | Rice University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Flying: Efficiency thanks to Lightweight Air Nozzles

23.10.2017 | Materials Sciences

Salmonella as a tumour medication

23.10.2017 | Life Sciences

50th Anniversary at JULABO GmbH

23.10.2017 | Press release

VideoLinks
B2B-VideoLinks
More VideoLinks >>>