This soluble implant could revolutionize pain management | Innovation

Millions of Americans live in pain. Pain can be an important indicator of health, but it can also cause debilitation, fatigue, depression, and poor quality of life.Researchers at Johns Hopkins University and George Washington University estimated that the pain would affect the United States. $ 560 billion to $ 635 billion In 2011.

In the 1990s, pharmaceutical companies claimed that there was an answer: opioids. After these drugs were guaranteed to be non-addictive, doctors were free to prescribe opioids in hopes of relieving the patient’s pain.

However, opioids are highly addictive and substance abuse has escalated as doctors increasingly prescribe them. Some patients turned to heroin and synthetic opioids when prescription drugs were not available and almost died from opioid overdose between 1999 and 2019. 500,000 people In the United States, in 2017, the US Department of Health and Human Services declared an opioid epidemic. Public health emergencies..

Since discovering opioid addiction, scientists have been looking for safer alternatives to relieve pain. John A. Rogers, a biomedical engineer at Northwestern University, believes he may have created an implantable, soluble device that cools nerves in the body.

“Pain management is an important aspect of patient care in many situations, which is currently achieved with various types of analgesics, and opioids are probably the most prominent,” he says. “These schemes are very effective in relieving pain, but they have different types of side effects. Among them, the tendency for addiction is prominent.”

Instead, Rogers and his team thought they could design a device that would allow for more targeted pain relief, depending on the intensity of the pain. Using cooling, the implant paralyzes certain peripheral nerves that connect the brain and spinal cord to the rest of the body. This measure blocks the pain signal to the brain and effectively regulates pain in certain parts of the body.

“Anyone who has been outdoors on a cold day knows that if their hands and fingers get too cold, they start to lose their sense of touch,” he explains. “Your fingertips are almost numb, and what we’re trying to take advantage of is just that cooling effect.”

The team created what Rogers called a “rubber band” with embedded small channels slightly larger than human hair. One side of the 5mm wide device ends with a cuff-like structure that surrounds the nerve. The other comes out of the skin and is attached to the pumping device. This is similar to how an IV drip works. Coolant that boils at low temperatures is pumped into one of the narrow channels of the band to the nerve. It encounters dry nitrogen flowing through another channel and quickly evaporates to produce a cooling effect. The gas flows back through another channel and then recondenses and passes through the device again, forming a closed-loop system. This device is described in a new study published today. Chemistry..

A small temperature sensor inside the device allows the user to monitor and control nerve temperature by adjusting the flow of coolant. Overcooling the nerves can damage the tissue. The temperature sensor consists of four layers. The magnesium layer is encapsulated by two layers of silicon dioxide, the insulating material, and a layer below it that acts as an adhesive.

“Current can flow through that magnesium layer (metal), and the resistance of that metal changes as a function of temperature,” Rogers explains.

The device is also completely soluble in the body, eliminating the risks associated with surgical removal. The time it takes to dissolve (usually days or weeks) depends on the material used and its thickness.Rogers Number of electronic devices What the body can absorb Temporary pacemaker In 2021. In 2013 he won Smithsonian magazine American Ingenuity Award For his work.

Researchers tested the device on the rat’s sciatic nerve, which carries sensory signals from nerves that end in the foot. By applying pressure to the rat’s paw, we measured the force required for the rat to retract its appendages.

“The idea is that when you create a numbing sensation in your foot, you need to push harder and harder to create that contractile response,” Rogers says. “Therefore, cooling sciatica can increase the threshold pressure that needs to be applied to the foot by about 10 times.”

Now, Rogers says the next step is to look at the biological aspects of the human body and improve the functionality of the device. It is important to understand the limits of the body, as supercooling can lead to nerve damage.

“After stopping cooling, how long does it take for my nerves to recover so that I can resume cooling?” He says. “These are the types of research that I consider to be the most important research that humans do before using the device.”

John woodA neurobiologist at the University College London, is more skeptical of this pain reliever. Wood is studying pain pathways, including Nav1.8, which is important for relaying pain signals from nerves throughout the body to the spinal cord.

“Given the global nature of many chronic pain syndromes, I don’t think this approach is attractive,” Wood wrote in an email, adding that implantable devices are “problematic.”

According to Wood, drugs like the Nav1.8 inhibitor from pharmaceutical company Vertex, which are given in the form of tablets, have shown a strong pain-relieving effect on humans.Recently, the top publication The Nav1.8 inhibitor VX-548 outperformed placebo in two post-surgical acute pain phase II trials.

“This is a much bigger step forward,” he writes.

Rogers agrees that every implant carries risks, but his team sought to minimize the risks through engineering. A soft rubber band-like structure as thick as a piece of paper moves naturally with the muscle tissue surrounding the nerve, and the solubility of the device minimizes the risk of nerve damage due to removal. He says.

This device allows users to adjust their pain relief. This is described by Rogers as the main advantage.

“It doesn’t have any kind of drug-based approach, it provides all sorts of engineering controls that are offered in a very targeted way,” he explains. “Therefore, instead of running around the whole body as in many types of painkillers, this device actually works only on the parts of the body that are associated with suppressing the sensation of pain.”

Laura Bohn, a biochemist at the University of Florida’s Scripps Biomedical Research, calls the device “innovative” and “innovative.” She says pain needs to be approached from different angles. “There are so many kinds of mechanisms to adjust it, just as there are so many kinds of pain,” she explains.

Bonn is studying how receptors in the body, such as opioids, serotonin, and cannabinoids, work in the hope of finding new ways to treat pain and addiction. “The more tools we have, the more opportunities we have to improve our treatment,” she adds. “I think everyone is trying to replace opioids, but with proper use, I personally still have room for opioids, so this is another step in building a toolbox. I think.”

Rogers believes the device can be used in hospitals for acute post-surgery pain. The surgeon inserts the device towards the end of the surgery (if the patient has already been opened), sutures the surgical site, pulls the tube out of the skin and keeps it attached to the pump. The patient is then connected to an external pumping device for a period of time.

In the distant future, he believes that the system can be adapted for use at home by patients, although more engineering will be required.

“We’re pretty excited, but at the same time we understand that there’s additional work we need to do,” he says. “I think it’s great to be able to switch pain on and off. Perhaps this is one approach to doing that.”