There are many kinds of bandages, aside from the Band-Aids and stretchy cloth wraps for sprains we all know. However, in recent years, applications have gotten so futuristic that they can even accelerate healing inside the body by converting movement energy into electrical currents that zap wounds, healing broken bones, and repairing injured muscles. Furthermore, scientists have created internal healing bandages for organs, a complicated task since the inside of our bodies is always wet and contains acids and enzymes that can break down foreign materials.

The following studies have found ways to deal with the hostile environment under our skin to materialize impressive new internal bandages and implants, furthering the medical field into the previously impossible territory.

Scientists at the National University of Ireland Galway’s Center CURAM developed an implantable stimulator device that combines with the body to accelerate the internal healing of damaged tendons. People can use the motion-powered mesh to treat disease or damage, like a sports injury. The technology acts as a switch to turn on highly targeted regenerative processes of tendons.

This research uses piezoelectric materials, which have formed the basis of many studies of forward-thinking technologies. The material is a fabric-like mesh that generates electrical currents when subjected to mechanical pressure. Other studies have developed specialized roads, shoes, and objects like chin straps that harvest energy from chewing. The CÚRAM team sought to investigate its potential in regenerating damaged tendons.

Study author Dr. Marc Fernandez, who carried out the principal study research, said:

“We presented an implantable, electrically active device capable of controlling tendon regeneration and healing. Importantly, our research improved the therapeutic performance of the device by enhancing its structure, piezoelectric characteristics, and biological compatibility. We also evaluated the individual influence of mechanical, structural, and electrical cues on tendon cell function and were able to show that bioelectric cues contribute significantly in promoting tendon repair.

Successful treatment of tendon damage and disease represents a critical medical challenge. Our discovery shows an electrical charge produced in the treatment target area – the damaged or injured tendon – when the implanted device is stretched during walking. The potential gamechanger here is like a power switch in a cell – the electrical stimulus turns on tendon-specific regenerative processes in the damaged tendon.”

Their experiments coupled electrical therapy with exercise. They fabricated the stimulation device by weaving nanoscale fibers of piezoelectric material into a flexible mesh.

Their study demonstrates how simply walking is enough to power an implantable stimulator device and speed up the treatment of musculoskeletal diseases. In addition, their findings establish the engineering foundations for further developments of devices that enable musculoskeletal tissue regeneration control without external stimulation or drugs.

CÚRAM Investigator and lead researcher Dr. Manus Biggs explained:

“One of the most exciting parts of our study is that these implantable devices may be tailored to individual patients or disorders and may show promise in accelerating the repair of sport-related tendon injuries, particularly in athletes.

This unique strategy of combining a device which is powered through body-movement and which can induce accelerated tendon healing is expected to significantly impact the field of regenerative devices, specifically in the area of sports or trauma associated injuries. These devices are cost-effective, relatively easy to implant, and may pave the way for a whole new class of regenerative electrical therapies.”

The team hopes this study can lead to new options for orthopedic surgeons, ones that allow them to sidestep the need for drug treatments or tendon grafting.

Scientists from Switzerland’s Empa research institute designed a polymer patch for the digestive tract to better internal healing of wounds by stably bonding and sealing injuries. Closing digestive tract wounds is a considerable challenge, so this is a significant accomplishment.

Reattaching tissue from the digestive tract isn’t easy because sutures alone can’t keep food waste and digestive fluids from leaking out into the abdominal cavity. Furthermore, emergencies like a burst appendix or intestinal volvulus have to be treated by surgeons immediately.

However, current biodegradable protein patches applied over stitched-closed digestive tract wounds often dissolve too quickly when exposed to stomach acids or don’t remain adhered long enough. Resultantly, surgeries run the risk of post-surgical complications such as sepsis or peritonitis.

Inge Herrmann, an Empa researcher who is also a professor for nanoparticulate systems at ETH Zurich, said:

“Leaks after abdominal surgery are still one of the most feared complications today.”

Fortunately, Empa’s new hydrogel patch may be the perfect solution, thoroughly sealing such injuries up. The team collaborated with a colleague from Britain’s Queen Elizabeth University Hospital on the development of the patch, which is a synthetic composite material made of four biocompatible substances: acrylic acid, acrylamide, bis-acrylamide, and methyl acrylate.

Together, these acrylic substances form a chemically stable hydrogel. As a patch, the hydrophobic (water-repelling) composite molecules actively cross-link with those of the intestinal tissue so no fluid can pass through. The result is a robust and long-lasting bond. The material even expands if digestive juices leak out beneath the wound patch, closing onto the tissue tighter.

Empa researcher Dr. Alexandre Anthis, who co-led the study, said:

“Adhesion is up to 10 times higher than with conventional adhesive materials. Further analysis also showed that our hydrogel can withstand five times the maximum pressure load in the intestine.”

Furthermore, the biocompatible super is inexpensive because it primarily consists of water. Thus, it could shorten hospital stays and save healthcare costs simultaneously.

Electrical devices to speed healing made of piezoelectric material have had a downside; they often can’t be implanted in soft tissue. But thanks to a new development by scientists led by Prof. Xudong Wang at the University of Wisconsin, that could soon change.

The team made a piezoelectric wafer, a patch-like tissue-stimulating implant made of non-toxic amino acid lysine crystals that form between two polyvinyl alcohol (PVA) sheets via a self-assembly process. PVA is a flexible, biocompatible, and biodegradable polymer. In addition, the crystals are piezoelectric, so they generate an electrical charge when subjected to mechanical stress.

In experiments with rats, the crystal/PVA wafers implanted in the animals’ chests and legs produced a measurable electrical output from regular muscle movements. In addition, the wafers had no harmful effects when dissolved. The team proved this with blood tests. The group says the currents could stimulate adjacent injured biological tissue, aiding in the healing process.

“We believe the technology opens a vast array of possibilities including real-time sensing, accelerated healing of wounds and other types of injuries, and electrical stimulation to treat pain and other neurological disorders. Importantly, our rapid self-assembling technology dramatically reduces the cost of such devices, which has the potential to greatly expand the use of this promising form of medical intervention.”

This isn’t Prof. Wang’s first creation. His previous accomplishments include a wound-stimulating external bandage powered by breathing movements of the chest and a triboelectric patch placed on broken bones to hasten their healing.

Nagoya City University researchers developed a 3D bio-printed drug delivery system: a polymer hydrogel implantable healing patch made primarily of fish gelatin. The gelatin is relatively low-cost, and fish as a material doesn’t tend to clash with any religious or personal beliefs. Plus, the patch has a photosensitive component so that the researchers can control the release rates of drugs by varying UV exposure times.

Rice University researchers developed an innovative way to repair heart tissue and reduce scarring by implanting capsules filled with stem cells near the damaged heart. In experiments, they filled alginate hydrogel capsules, a biocompatible material made from brown algae, with mesenchymal stem cells (MSCs) and implanted them in mouse models. After four weeks, the hearts of the animals that received the ‘coated’ stem cells had healed 2.5 times more effectively than those with non-coated stem cells.

A research team at North Carolina State University and UNC-Chapel Hill developed a cell-free “off-the-shelf” artificial cardiac patch that improved internal healing in mice and pigs. A cardiac patch works by helping the heart regenerate healthy tissue post-injury and restore the organ to proper function. The “off-the-shelf” patch differs from a standard cardiac patch in that it doesn’t use living cells, which makes them more reliable. The result is a patch that contains all the therapeutic benefits secreted by the cells but without the living cells that could trigger an unwanted immune response. When they tested the artificial cardiac patch on a rat model of a heart attack, it resulted in a 50% improvement in cardiac function over three weeks compared to non-treatment and a 30% reduction in scarring at the site of injury.

Meanwhile, other scientists from Imperial College London developed a “pumping” patch containing millions of living and beating stem cells that help repair the damage caused by a heart attack. The patches are intended to physically support the damaged heart muscle and help it pump more efficiently. It also releases chemicals that stimulate the heart cells to repair and regenerate. First, one or more thumb-sized (3cm x 2cm) patches of heart tissue are grown in a lab from a sample of the patient’s own cells. Next, it’s sewn onto the patient’s heart, where it turns into a healthy working muscle, preventing or even reversing damage to the organ. In the lab, tests show that the patches start to beat after three days and begin to mimic mature heart tissue within a month. In animals, the patches improved the heart’s function after a heart attack, and blood vessels from the heart even grew into the patches.

Lastly, Scientists in Switzerland and China joined forces to develop an implantable internal healing medical device that imitates blood vessels’ primary function but beyond its natural counterparts’ capabilities. For the study, the researchers demonstrated on rabbits how these electronic blood vessels could be used to facilitate blood flow, and assist in drug delivery, gene therapy, and wound healing. The devices are also flexible, biodegradable, and can coordinate with other electronic devices to take on tasks, including drug delivery, via its built-in circuitry.