The skin is remarkably good at keeping things out of the body, which becomes a problem when medicine needs to get in. A pill taken for a skin condition must pass through the stomach and bloodstream and travel throughout the body just to reach the skin. Applying a drug directly to the skin seems simpler, but the skin’s outer layer blocks most of the medicines meant to treat it. Microneedle patches can help drugs get through, but they work best on small areas and are impractical for conditions such as eczema and psoriasis, which can cover broad or irregularly shaped…

Brushing is the most common way people care for their teeth each day, yet the basic toothbrush has changed little beyond its scrubbing action in more than a thousand years. Dental plaque is a complex film of bacteria protected by a sticky matrix, which makes it hard for brushing alone to clear bacteria from deep layers and the spaces between teeth. Brushing also leaves no lasting protection on the tooth surface, so bacteria can recover and recolonize within hours. Antibacterial toothbrushes that add chemical agents such as metal ions to their bristles may not stay effective over time, and ionic…

Gastrointestinal fistulas are abnormal passages that form between the digestive tract and another organ or tissue. They are a common complication of surgery, trauma, inflammatory diseases, and cancerous tumors, and severe cases can be life-threatening. Doctors often treat them endoscopically, but current methods have drawbacks. Stents can migrate out of place, fistulas closed with titanium clips can come back, and endoscopic suturing is technically difficult. Unwanted tissue adhesions after treatment add further complications. Researchers at the Institute of Process Engineering of the Chinese Academy of Sciences have developed a sealant inspired by slugs that can be injected through a standard…

Our sense of smell helps us find our way through the world and plays a key role in perception, flavor, and emotion, yet it is notoriously hard to recreate digitally. Losing it is linked to many neurological diseases and infections. Interfaces that connect people with machines, used in fields ranging from medical research to online gaming, mostly rely on touch, sound, and sight, leaving smell out of the picture. Researchers at The Ohio State University have developed a system that detects and analyzes odors and releases scents through wearable devices, a step toward bringing smell into digital experiences and toward…

Inside every healthy eye, a clear lens focuses incoming light onto the retina. When proteins within that lens become damaged or clump together, the lens grows cloudy and can no longer focus light properly, a condition known as a cataract. Cataracts are among the leading causes of vision loss and blindness, affecting an estimated 94 million people worldwide, and surgery is currently the only treatment. Researchers at Anglia Ruskin University in the United Kingdom have now grown realistic miniature human lenses in the lab from stem cells for the first time, opening a potential new route for understanding and eventually…

Rebuilding strength in the muscles used for speaking often depends on exercises that patients with voice disorders must practice largely on their own. Speech pathologists can prescribe muscle-strengthening routines, but they may see patients for only 30 minutes a week or even once a month, leaving patients with no way to tell whether they are using the right muscles correctly while practicing at home. Researchers at McGill University have developed a putty-like electrode that molds to the skin and could help close that gap by improving the treatment and monitoring of voice disorders and upper airway diseases. Sensors that measure…

An estimated 18,000 spinal cord injuries occur in the United States each year, most often from vehicle accidents. After the surgery that typically follows such an injury, patients recover in the intensive care unit, where they remain at risk for serious complications such as stroke, blindness, or further loss of movement control. Getting a picture of what is happening at the injury site often means imaging that requires moving patients who cannot move on their own, and it captures only single moments in time. Engineers and surgeons at Johns Hopkins Medicine have now completed a first proof-of-concept study showing that…

Continuous glucose monitors give millions of people with diabetes a real-time view of their glucose levels, helping them make decisions about medication, diet, and daily activities. Yet these devices remain out of reach for some patients because of their cost. Researchers at Texas A&M University have taken a step toward solving that problem by identifying a lower-cost component for an experimental injectable glucose sensor. The new sensing material costs roughly one-tenth as much as a commonly used alternative while delivering similar performance. Many glucose-monitoring systems depend on enzymes to detect glucose. The approach developed by the research team works without…

For decades, scientists have been developing neuroprosthetic limbs, which use signals from the muscles left after an amputation to guide an artificial limb. Information about how far a muscle stretches, how fast it moves, and how strongly it activates can be fed into the limb’s control system, helping people with leg amputations walk more naturally and helping those with arm amputations handle objects more effectively. These devices have traditionally relied on electrodes placed on the skin to measure muscle activity, but those readings have not been reliable enough to keep someone safe while walking on a neuroprosthetic leg. Researchers at…

Type 2 diabetes is on the rise around the world. Unlike type 1 diabetes, it often stems from obesity, inactivity, and taking in more energy than the body needs over many years. Insulin injections can bring blood sugar down, but they do nothing about the body’s long-term energy surplus. Researchers at ETH Zurich have now developed an implantable system that relies on an electrically powered catalyst to reduce blood glucose. The research team has spent years exploring systems that regulate blood sugar. Their earlier designs were built on custom genetic networks, but because those systems depend on biological parts, they…