Joint study raises questions about treatments for arthritis

August 3, 2018 by Lachlan Gilbert, University of New South Wales

A study examining how molecules are transported into knee-joint tissue could have major implications for understanding and treating arthritis.

UNSW biomedical engineers have shown for the first time that a mixture of variously-sized in the bloodstream can be separated by the constituent tissues of a healthy knee-joint.

And an arthritic joint was observed to disrupt the of the molecules, but interestingly, not halt them altogether.

School of Biomedical Engineering Professor Melissa Knothe Tate and PhD trainee Lucy Ngo wanted to build on the Professor's previous research that "showed for the first time that the different calibre porosities of bone act as a molecular sieve".

"This time, Lucy and I studied what would happen if we mixed all the different sizes together and delivered them as a single bolus," Professor Knothe Tate said.

"We were startled to see that the tissues separated out the different sizes of molecules."

The researchers used guinea pigs, literally, for their study, because like humans, they naturally get arthritis with age. They injected a mixture of colour-coded molecules of different sizes into the hearts of young (eight to 10 months) and aged (17 to 19 months) guinea pigs to observe where in the joints those molecules ended up, if at all.

They observed differences in the molecular transport between the young and the old, with major disruption of the transport in the aged guinea pigs' joints due to tissue degeneration associated with arthritis.

"This could have major implications for our understanding of how arthritis and associated degeneration progress as well as how we might use this knowledge to preferentially treat areas of degeneration, for example through targeted pharmaceutical delivery strategies," Professor Knothe Tate said.

A surprising turnup in the study was that very little fluorescence showed up in the muscle, meaning the coloured molecules were easily transported into bone, cartilage, meniscus and ligament, but not muscle. Professor Tate suggested this may have been because the guinea pigs were anaesthetised before being injected with the dye.

"Our working hypothesis is that muscle needs physical activity (flexion or extension) to pump the molecules," Professor Knothe Tate said.

Professor Knothe Tate said she is working towards exploring this idea further in a future study using MRI to observe the transport of molecules in real time while mechanically loading the limb during the procedure.

"This will let us to determine the time course of transport as well as the role of active muscle activity on transport, which has implications well beyond arthritis."

The results of the most recent work have prompted the Professor to re-evaluate former assumptions about molecule transportation to damaged joints.

She said she has always wondered whether the positive anecdotes about orally administered glycosaminoglycans (available commercially as Glucosamine) on people with arthritic joints made sense at all, as there were no guarantees the polysaccharides could even get to the targeted areas.

But her latest study suggest this may still be possible.

"Of course, we have to follow up with further studies, but the data showing massive disruption to transport pathways may actually indicate opening up of new transport pathways."

Professor Knothe Tate and Lucy Ngo's work was documented in a paper titled "Knee Joint Tissues Effectively Separate Mixed Sized Molecules Delivered in a Single Bolus to the Heart" which appeared on www.nature.com last month.

Explore further: 'Google Maps' for the body: A biomedical revolution

More information: Lucy Ngo et al. Knee Joint Tissues Effectively Separate Mixed Sized Molecules Delivered in a Single Bolus to the Heart, Scientific Reports (2018). DOI: 10.1038/s41598-018-28228-w

Related Stories

'Google Maps' for the body: A biomedical revolution

March 30, 2015
A world-first UNSW collaboration that uses previously top-secret technology to zoom through the human body down to the level of a single cell could be a game-changer for medicine, an international research conference in the ...

Using stem cells from hip replacements to help treat ageing adults

January 30, 2014
(Medical Xpress)—The tissue normally discarded during routine hip replacements could be a rich new source of adult stem cells for use in regenerative medicine, UNSW-led research has found.

It's all in the wrapping: Mimicking periosteum to heal traumatic bone injury

December 13, 2011
A manmade package filled with nature's bone-building ingredients delivers the goods over time and space to heal serious bone injuries faster than products currently available, Cleveland researchers have found.

Researchers use nature's weaving formula to engineer advanced functional materials

January 11, 2017
For the first time, UNSW biomedical engineers have woven a 'smart' fabric that mimics the sophisticated and complex properties of one nature's ingenious materials, the bone tissue periosteum.

Researchers use natural and artificial sheaths to mend traumatic bone loss

March 9, 2010
A husband and wife research team has found a way to use the sleeve-like cover on bone to heal serious bone injuries faster and more simply than current methods. And they've developed an artificial sleeve that spurs fast healing ...

Better than a pill: Team to develop new arthritis treatment via silk

February 10, 2017
A twisted ankle, broken hip or torn knee cartilage are all common injuries that can have medical ramifications long after the initial incident that causes them. Associated pain, inflammation, joint degeneration and even osteoarthritis ...

Recommended for you

Research shows diet has little influence on precursor to gout

October 11, 2018
Dietary factors have a far smaller influence on urate levels (a precursor to gout) than previously envisaged, new University of Otago research reveals.

More doctor visits lead to less suicide attempts for fibromyalgia patients

September 19, 2018
Fibromyalgia patients who regularly visit their physicians are much less likely to attempt suicide than those who do not, according to a new Vanderbilt University Medical Center study published in Arthritis Care & Research.

Antioxidant found to be effective in treating mice with osteoarthritis

September 14, 2018
A team of researchers in Belgium and the Netherlands has found that feeding a common antioxidant to test mice was effective in treating osteoarthritis. In their paper published in Science Translational Medicine, the group ...

Researchers find answers as to why some people are at risk of gout

September 12, 2018
University of Otago researchers have helped characterise a genetic variant that enables new understanding of why some people are at risk of gout, a painful and debilitating arthritic disease.

Emotions like anger and sadness may cause pain as well as being a result of it

September 10, 2018
While emotions such as anger or sadness are often thought of as being a result of stress or pain, findings recently published by Penn State researchers suggest that negative or mixed emotions could function as stressors themselves.

Dietary carbohydrates could lead to osteoarthritis, new study finds

August 9, 2018
Do your knees ache? According to new findings from the Oklahoma Medical Research Foundation, your diet could be a culprit.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.