New Lab-Made Cartilage to Rebuild Your Knees Efficiently

Over-the-counter pain relievers, physical therapy, steroid injections — some people have tried it all and are still dealing with knee pain. Often knee pain comes from the progressive wear and tear of cartilage known as osteoarthritis, which affects nearly one in six adults — 867 million people — worldwide. For those who want to avoid replacing the entire knee joint, there may soon be another option that could help patients get back on their feet fast, pain-free, and stay that way.

Writing in the journal Advanced Functional Materials, a Duke University-led team says they have created the first gel-based cartilage substitute that is even stronger and more durable than the real thing. Mechanical testing reveals that the Duke team’s hydrogel — a material made of water-absorbing polymers — can be pressed and pulled with more force than natural cartilage, and is three times more resistant to wear and tearImplants made of the material are currently being developed by Sparta Biomedical and tested in sheep. Researchers are gearing up to begin clinical trials in humans next year.

Duke researchers have developed a gel-based cartilage substitute to relieve achy knees that’s even stronger and more durable than the real thing. Clinical trials to start next year

If everything goes according to plan, the clinical trial should start as soon as April 2023,” said Duke chemistry professor Benjamin Wiley, who led the research along with Duke mechanical engineering and materials science professor Ken Gall.

To make this material, the Duke team took thin sheets of cellulose fibers and infused them with a polymer called polyvinyl alcohol — a viscous goo consisting of stringy chains of repeating molecules — to form a gel. The cellulose fibers act like the collagen fibers in natural cartilage, Wiley said — they give the gel strength when stretched. The polyvinyl alcohol helps it return to its original shape. The result is a Jello-like material, 60% water, which is supple yet surprisingly strong.

Natural cartilage can withstand a whopping 5,800 to 8,500 pounds per inch of tugging and squishing, respectively, before reaching its breaking point. Their lab-made version is the first hydrogel that can handle even more. It is 26% stronger than natural cartilage in tension, something like suspending seven grand pianos from a key ring, and 66% stronger in compression — which would be like parking a car on a postage stamp. “It’s really off the charts in terms of hydrogel strength,” Wiley said.

The team has already made hydrogels with remarkable propertiesIn 2020, they reported that they had created the first hydrogel strong enough for knees, which feel the force of two to three times body weight with each step.

Source: https://today.duke.edu/
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https://www.spartabiomedical.com/

Amputee Feels In Real-Time With Bionic Hand

Nine years after an accident caused the loss of his left hand, Dennis Aabo Sørensen from Denmark became the first amputee in the world to feel – in real-time – with a sensory-enhanced prosthetic hand that was surgically wired to nerves in his upper arm. Silvestro Micera and his team at EPFL Center for Neuroprosthetics (Ecole Polytechnique Fédérale de Lausanne in Switzerland) and SSSA (Italy) developed the revolutionary sensory feedback that allowed Sørensen to feel again while handling objects. A prototype of this bionic technology was tested in February 2013 during a clinical trial in Rome under the supervision of Paolo Maria Rossini at Gemelli Hospital (Italy). The study is published in the February 5, 2014 edition of Science Translational Medicine, and represents a collaboration called Lifehand 2 between several European universities and hospitals.
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The sensory feedback was incredible,” reports the 36 year-old amputee from Denmark. “I could feel things that I hadn’t been able to feel in over nine years.” In a laboratory setting wearing a blindfold and earplugs, Sørensen was able to detect how strongly he was grasping, as well as the shape and consistency of different objects he picked up with his prosthetic. “When I held an object, I could feel if it was soft or hard, round or square.

Micera and his team enhanced the artificial hand with sensors that detect information about touch. This was done by measuring the tension in artificial tendons that control finger movement and turning this measurement into an electrical current. But this electrical signal is too coarse to be understood by the nervous system. Using computer algorithms, the scientists transformed the electrical signal into an impulse that sensory nerves can interpret. The sense of touch was achieved by sending the digitally refined signal through wires into four electrodes that were surgically implanted into what remains of Sørensen’s upper arm nerves.

This is the first time in neuroprosthetics that sensory feedback has been restored and used by an amputee in real-time to control an artificial limb,” says Micera. “We were worried about reduced sensitivity in Dennis’ nerves since they hadn’t been used in over nine years,” says Stanisa Raspopovic, first author and scientist at EPFL and SSSA. These concerns faded away as the scientists successfully reactivated Sørensen’s sense of touch.

Source: https://actu.epfl.ch/