June 4, 2013 Cartilage injuries are difficult to repair. Current surgical options generally involve taking a piece from another part of the injured joint and patching over the damaged area, but this approach involves damaging healthy cartilage, and a person's cartilage may still deteriorate with age.

Bioengineers are interested in finding innovative ways to grow new cartilage from a patient's own stem cells, and, thanks to a new study from the University of Pennsylvania, such a treatment is a step closer to reality.

The research was conducted by associate professor Jason Burdick of the Department of Bioengineering in the School of Engineering and Applied Science and associate professor Robert Mauck of the Department of Orthopaedic Surgery in Penn's Perelman School of Medicine. Liming Bian and Murat Guvendiren, members of Burdick's lab, also took part.

It was published in the Proceedings of the National Academy of Sciences.

"The broad picture," Burdick said, "is trying to develop new therapies to replace cartilage tissue, starting with focal defects -- things like sports injuries -- and then hopefully moving toward surface replacement for cartilage degradation that comes with aging. Here, we're trying to figure out the right environment for adult stem cells to produce the best cartilage."

"As we age, the health and vitality of cartilage cells declines," Mauck said, "so the efficacy of any repair with adult chondrocytes is actually quite low. Stem cells, which retain this vital capacity, are therefore ideal."

Burdick and his colleagues have long studied mesenchymal stem cells, a kind of adult stem cell found in bone marrow that is capable of turning into bone, fat or cartilage cells. His group has been particularly interested in deducing the microenvironmental signals that tell these cells which way to differentiate. A recent paper from his group investigated conditions that can preferentially coax these stem cells into becoming either fat-like or bone-like cells while encapsulated in hydrogels, polymer networks that simulate some of the environmental conditions in which stem cells naturally grow.

The first step in growing new cartilage is initiating chondrogenesis, or convincing the mesenchymal stem cells to differentiate into chondrocytes, which in turn generate the spongy matrix of collagen and sugars that cushions joints. One challenge in prompting this differentiation is that, despite the low density of adult chondrocytes in tissues, the actual formation of cartilage begins with cells in close proximity.

"In typical hydrogels used in cartilage tissue engineering," Burdick said, "we're spacing cells apart, so they're losing that initial signal and interaction. That's when we started thinking about cadherins, which are molecules that these cells use to interact with each other, particularly at the point they first become chondrocytes."

To simulate that environment, the researchers used a peptide sequence that mimics these cadherin interactions, which they bound to the hydrogels used to encapsulate the mesenchymal stem cells.

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New way to improve stem cells' cartilage formation

Can belly fat prevent blindness? New research says for diabetics it might.

Right now there is no cure for degenerative eye disease in people who have diabetes but researchers at the University of Virginia School of Medicine may be on the brink of changing that result. They are using stem cells from belly fat of the same person with the eye disease to prevent and reverse blindness.

The leading cause of blindness in the United States today is retinopathy, a degenerative eye disease resulting from diabetes.

"The functional effect on these people's lives is dramatic. They lose their vision and they lose their job so the effects it can have on both them and their families are dramatic," Dr. Paul Yates, an assistant professor of ophthalmology and biomedical engineering at UVA stated.

Yates explains that 40 percent of diabetics will develop retinopathy. Treatment requires either a shot of medicine directly in the eye every month or surgery.

"Right now we don't have a lot of great treatment. We have techniques we were using back in the 1950s. One option is to take a laser and destroy most of the back of the eye in order to save some of the eye," he said.

But neither procedure prevents blindness, the eventual result, they just slow the process down. Now, there is new promise.

In a paper published Friday, Yates along with other researchers at UVA show that taking stem cells from belly fat and injecting them into the same person's eye may prevent the blood vessels from decay.

Tom Mendal is a M.D. / Ph.D.student at UVA who isinvolved in the research and publication. "One way that this could happen is that down the line, after lots of trials, we might be able to take your own adult stem cells and take them out and grow them in the lab and introduce them into your eye and potentially treat and even prevent the disease from occurring in the first place. Because we know that you get diabetes before the disease starts to happen," he stated.

Yates and Mendal say that if favorable results continue on mice and then in clinical trials, this discovery may be available to the public within the next 10 years.

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Stem Cells Show Potential to Treat Leading Cause of Blindness

Australian scientists have created a test to work out whether certain types of stem cells are unsafe.

The CSIRO has spent five years developing a safety test for induced pluripotent (iPS) stem cells.

iPS stem cells do not require a human embryo and are considered an important research advance.

Last month, scientists were able to .

There is much debate in the scientific community about the advantages of iPS stem cells over their embryonic counterparts.

The CSIRO's Andrew Laslett says there is still a number of question marks about the long term stability and safety of iPS cells.

"At this stage it appears that human embryonic stem cells may be slightly safer, but it's early days," he said.

Dr Laslett says the new test will provide more information about the quality of iPS and help identify unwanted cells that can mutate.

"Sometimes the cells that are made from the iPS cells change back into stem cells which are unwanted because these cells can form tumours called teratomas," he said.

Dr Laslett is hoping the research will be used to ensure stem cell therapies are safe for humans.

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CSIRO scientists develop safety test for induced pluripotent stem cells