Medical

Hydrogel that outperforms cartilage could be in human knees in 2023

Hydrogel that outperforms cartilage could be in human knees in 2023
A new hydrogel material that outperforms natural cartilage could make for better knee replacements
A new hydrogel material that outperforms natural cartilage could make for better knee replacements
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A new hydrogel material that outperforms natural cartilage could make for better knee replacements
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A new hydrogel material that outperforms natural cartilage could make for better knee replacements
A sample of the new cartilage-replacing hydrogel, attached to its titanium base for an implantable device
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A sample of the new cartilage-replacing hydrogel, attached to its titanium base for an implantable device

Joint pain is a common ailment of aging, thanks to cartilage’s tendency to wear out. Now, researchers at Duke University have developed a new hydrogel that’s stronger and more durable than the real thing, which could make for longer lasting knee implants.

Natural cartilage plays an important role in cushioning joints, but unfortunately it doesn’t regenerate itself very well after damage by age or injury. Current treatment options are usually limited to pain medication, physical therapy, or if things progress too far, a total knee reconstruction. But if the Duke team’s new work pans out, a better option might soon be available.

Soft and flexible, hydrogels have been investigated as potential cartilage replacement materials, but most of them have been too weak to support much weight. In 2020 the Duke team created a hydrogel that had properties that were as good as natural cartilage – and now they’ve developed a version that surpasses the real thing.

The new hydrogel is made up of cellulose fibers, which make the material strong while being stretched, infused with polyvinyl alcohol that helps it return to its original shape. The team also tweaked its manufacturing method too – rather than freezing and thawing it like most hydrogels, they annealed it like glass, which triggers more crystal formation in the polymer network.

The end result is a hydrogel with a tensile strength (withstanding stretching) of 51 Megapascals (MPa), and a compressive strength (withstanding pressure) of 98 MPa. That’s 26% higher tensile strength and 66% higher compressive strength than natural cartilage, the team says. It’s also five times the tensile strength and twice the compressive strength of other hydrogels made by freezing and thawing.

A sample of the new cartilage-replacing hydrogel, attached to its titanium base for an implantable device
A sample of the new cartilage-replacing hydrogel, attached to its titanium base for an implantable device

In other tests, the team used a machine to rub their artificial cartilage against natural cartilage a million times, under pressure similar to that on the knee during walking. And again, the artificial version proved to be three times more wear-resistant than natural cartilage.

Hydrogels have historically been tricky to anchor to bone in a knee joint, so the team also experimented with an implantable device to fix that. The hydrogel is cemented and clamped to a titanium base, which is then attached to a hole left by the damaged cartilage. This boasted a shear strength of 2 MPa, which is 68% stronger than natural cartilage’s grasp on bone.

The team says that implants made of the material are currently being tested in sheep, with human clinical trials to follow as soon as April 2023.

The research was published in the journal Advanced Functional Materials.

Source: Duke University

9 comments
9 comments
William
Hello Michael,have they done humam trials yet
Aross
Will it be tried on other joints?
Dr.Glove136
@William
According to the article, "...human clinical trials to follow as soon as April 2023." I hope this is sufficient to satisfy your curiosity.
Perr_M
Will a similar process be tested for hips also? What is the timeline there? Thanks. :)))
Pete0097
Where will the human trials be and what will the criteria be to be in them.
Smokey_Bear
Pete - It sounds like they partnered up with Sparta Biomedical, so if your looking to be a guinea pig, I'd start there.
ash
3 times more resistant maybe, but does it spontaneously regenerate / repair like human tissue ?
Matthew Corbett
@ash Cartilage has practically zero regenerative potential in adulthood, so once it's injured or gone, what we can do for patients has been very limited,” said assistant professor of surgery Charles K.F. Chan, PhD
LooseSends
@Pete0097

I'd imagine being in relatively good shape with a regular activity regimen would be favoured. They don't give new hearts and lungs to smokers for obvious reasons, so one would think that if you aren't already doing your best to take care of yourself then they would favour someone who is.