Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Way to Repair Cartilage Damage

09.03.2004


The new technique provide support for cartilage cells as they regenerate new cartilage tissue



Duke biomedical engineers have developed a technique to use a natural polymer to fill in and protect cartilage wounds within joints, and to provide supportive scaffolding for new cartilage growth. Their advance offers a potential solution for a central problem in generating new cartilage: providing a support for cartilage cells as they regenerate cartilage tissue.

In tests on rabbits, Lori Setton, associate professor of biomedical engineering at Duke’s Pratt School of Engineering, and her research team stimulated new cartilage growth in knee joint cartilage defects using a light-activated polymer hydrogel composed from a specialized molecule, hyaluronan. The hyaluronan-based polymer creates a protective cap over the wound, enabling joint movement while providing the structural support and chemical environment for new cartilage tissue to grow and fill the defect.


Dana Nettles, a graduate student in Setton’s laboratory, presented the research findings on Monday, March 8, 2004, at the Orthopedic Research Society Annual meeting in San Francisco. A paper titled "In Situ Crosslinkable Hyaluronan for Articular Cartilage Repair" will be published in the March 2004 issue of Annals of Biomedical Engineering.

"We feel that the outcomes from this study suggest that therapies like this one hold promise for future, successful cartilage repair procedures," said Nettles.

Trauma and injuries to the knees and hips commonly involve damage to the articular cartilage, the thin layer lining the ends of articulating joints. If left untreated, the cartilage defects do not repair because the local cells are unable to regenerate new tissue. Patients suffering from cartilage damage will go on to develop osteoarthritis, a degenerative joint disease characterized by the breakdown of the joint’s cartilage, causing pain and loss of movement. Nearly 21 million Americans suffer from osteoarthritis, principally in joints of the hip and knee.

Natural hyaluronan polymer in joints provides strength to cartilage and creates a cushioned self-lubricating surface that enables bones to rub against each other smoothly. Hyaluranon injections are already being used to ease joint pain, but the benefits fade after six months or so. Another approach involves culturing the patient’s own cells in the laboratory and then sewing a "tissue patch" into the injury site. Costing more than $26,000, the tissue patch approach works well for athletic injuries, but isn’t recommended for osteoarthritis treatment, said Setton.

Focusing on an alternative approach that provides for rapid and easy defect repair, Setton and her Duke University Medical Center colleague, T. Parker Vail of Orthopaedic Surgery, are developing a treatment to encourage natural cartilage tissue repair using the locally present cell population.

"Cartilage is a tissue that does not have the ability to heal itself, so there cannot be any healing without outside intervention," Vail continued. "There are still many hurdles and challenges to overcome, but we have been very encouraged by the positive results to date. The bringing together of the expertise of the disparate fields of engineering and medicine will yield the breakthroughs necessary to advance biomedical research."

In their process, the researchers first created a hyaluronan-based solution that easily pours into cartilage tears and fills in ragged wound margins. The hyaluronan was chemically altered to have multiple sticky sites that are used to latch on to each other.

The researchers then treat the polymer gel with laser light, turning the liquid into a solid, a process that takes about 30 seconds.

"The solid polymer creates a scaffold of support that fills the defect, and provides the correct physical and chemical cues to enable cells that move into the defect to differentiate appropriately into cartilage cells," said Setton.

Flexible and tough, the solid polymer has mechanical properties that can be controlled during synthesis for optimal function in the joint.

In a recently completed study, Vail applied the hyaluronan polymer to animal joint wounds in a operative procedure. After two weeks, cross sections showed that the material integrated well with existing cartilage tissue, and also encouraged cells to infiltrate and lay down new cartilage growth. The polymer also showed signs of degrading, something that needs to happen as new tissue grows to replace it, Setton said.

Calling the work a promising proof of concept, Setton said there is much work still to be done. Setton is working with Dana Nettles to optimize the properties that will make the hyaluronan polymer treatment most effective. For example, the researchers need to determine the pore size that optimizes nutrient diffusion and cell movement. They also need to know how much mechanical strength the polymer needs to maintain as new cells grow, and how quickly the polymer needs to degrade.

Ideally, Setton said she would like to develop a treatment that would last for at least 10 years.

"If we can heal lesions in joint cartilage with this type of bridge therapy, we could prevent end stage osteoarthritis that leads to knee replacements," she said.

Setton’s collaborators include Vail and Mark Grinstaff of Boston University. This research was funded by support from the National Institutes of Health, the Orthopaedic Research and Education Foundation, and a pre-doctoral National Science Foundation fellowship.

Deborah Hill | Duke University
Further information:
http://www.dukenews.duke.edu/news/repair_0304.html
http://settonlab.pratt.duke.edu/index.htm/

More articles from Life Sciences:

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht New antbird species discovered in Peru by LSU ornithologists
15.12.2017 | Louisiana State 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: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>