Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tissue Engineers Steering Stem Cells to Produce Bones, Cartilage

22.08.2002


Placing These Cells in Injectable Hydrogel May Provide New Way to Repair Joints



Johns Hopkins University researchers have caused stem cells from adult goats to grow into tissue that resembles cartilage, a key step toward creating a minimally invasive procedure that may one day be used to repair injured knees, noses and other body parts.

In this method, doctors would inject a fluid filled with stem cells and nutrients into damaged tissue, then use light to harden the liquid into a stable gel. Although human testing remains years away, the researchers believe stem cells within the gel will multiply and form new bone or cartilage to replace the injured tissue.


Paving the way for this technique, the researchers have conducted lab experiments that turned stem cells within a gel into cartilage-like tissue. The team expects to begin testing the process on mice this fall, says Jennifer Elisseeff, assistant professor in the Department of Biomedical Engineering. Elisseeff is leading a multi-disciplinary tissue engineering team that includes a plastic surgeon, an orthopedic surgeon, a polymer chemist and graduate students, all affiliated with the Whitaker Biomedical Engineering Institute at Johns Hopkins.

The team’s goal is to develop a new way to deliver and control the behavior of adult stem cells to restore bone and cartilage that has been damaged by disease or injury or is impaired by a genetic defect. Restoration of cartilage – the tough but elastic tissue in noses, ears and joints – would be particularly helpful because, unlike skin, cartilage does not naturally regenerate. Routine use of this procedure in humans may be many years away, Elisseeff says, but the potential benefits could be significant. For one thing, if the lab results can be replicated in humans, patients would end up with living tissue rather than metal or plastic replacement parts. “If this technique ultimately works the way we believe it will, doctors will have a new and possibly more effective option for treating severe joint injuries,” Elisseeff says. “This procedure would also help people avoid invasive surgery.”

Like many new research projects, this work uses stem cells because they have the ability to renew themselves and also to develop into many types of tissue. Elisseeff’s lab is using adult multipotent cells, meaning they can be stimulated to produce different types of musculoskeletal tissue. Ethical debates surrounding stem cell research have focused on material removed from human embryos and fetuses, not the adult cells used in Elisseeff’s experiments. Adult cells offer another advantage: In theory, patients preparing for cartilage or bone repairs will be able to donate their own stem cells prior to the procedure, reducing the likelihood of infection and tissue rejection.

MIT’s Technology Review magazine recently recognized Elisseeff, 28, as one of the World’s Top 100 Young Innovators in technology and business. Her current project, funded by the Arthritis Foundation, builds on work she began as a graduate student in the Harvard University-MIT Division of Health Sciences and Technology. Elisseeff was lead researcher in developing a polymer fluid–laced with cartilage cells called chondrocytes – that can be injected under the skin. The liquid is then hardened by shining an ultraviolet light or visible laser through the skin. The solid material,called a hydrogel, forms a scaffold or framework upon which cells can reproduce and form new tissue.

“Photopolymerizing hydrogels are very useful because they only harden when light is applied,” Elisseeff says. “Also, primary chondrocytes – cartilage cells – can be encapsulated in these hydrogels and will form cartilage-like tissue. The cells thrive because hydrogels contain plenty of water, which is needed to carry nutrients to these cells and move waste products away from them. The hydrogels also have enough space to allow the new tissue to form.”

Now, in a new lab at Johns Hopkins, Elisseeff and her colleagues are placing stem cells in her hydrogels and coaxing them to produce cartilage and an early form of bone within the polymer framework. Recently, Christopher Williams, a plastic surgery fellow in the lab, has conducted experiments with stem cells derived from the bone marrow of adult goats. By surrounding these cells with a specific growth factor that helps direct cellular differentiation, Williams has prodded the stem cells into forming what lab tests indicate are osteoblasts (cells that develop into bone) or chondrocytes. The cartilage samples show the proper gene expression and a cartilage-specific extracellular matrix. Lab tests show that the bone precursor cells are producing calcium, a first step toward osteogenesis, the formation of bone.

“This means that in the lab we’ve already used adult stem cells to create tissue resembling cartilage by composition and morphology in the photopolymerizing hydrogel, and early tests indicate this technique may work with bones, too,” Elisseeff says. “Other researchers have formed cartilage and bone from stem cells in the laboratory. But by applying this to the injectable hydrogel, we think we’ve come up with a clinically practical way to deliver the cells to the site of an injury, where they can grow to replace injured bone or cartilage. Some difficulties still exist in smoothly joining new cells to the recipient’s own tissue, but we’re working on these problems.”

Elisseeff’s team is now fine-tuning the technique. The researchers are synthesizing a new hydrogel that should degrade harmlessly in the body after the new tissue develops. Also, the team is refining its cell growth methods to more closely mimic the normal development of cartilage and bone cells. Elisseeff and her colleagues have submitted some of their lab results to a peer-reviewed journal.

Phil Sneiderman | EurekAlert!

More articles from Health and Medicine:

nachricht Infants later diagnosed with autism follow adults’ gaze, but seldom initiate joint attention
24.05.2019 | Schwedischer Forschungsrat - The Swedish Research Council

nachricht When wheels and heads are spinning - DFG research project on motion sickness in automated driving
22.05.2019 | Technische Universität Berlin

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: New studies increase confidence in NASA's measure of Earth's temperature

A new assessment of NASA's record of global temperatures revealed that the agency's estimate of Earth's long-term temperature rise in recent decades is accurate to within less than a tenth of a degree Fahrenheit, providing confidence that past and future research is correctly capturing rising surface temperatures.

The most complete assessment ever of statistical uncertainty within the GISS Surface Temperature Analysis (GISTEMP) data product shows that the annual values...

Im Focus: The geometry of an electron determined for the first time

Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.

The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

On Mars, sands shift to a different drum

24.05.2019 | Physics and Astronomy

Piedmont Atlanta first in Georgia to offer new minimally invasive treatment for emphysema

24.05.2019 | Medical Engineering

Chemical juggling with three particles

24.05.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>