All Patched Up: Space-Based Research to Help Heal Wounds on Earth

February 5, 2020 • By Amelia Williamson Smith, Staff Writer

With any cut or scratch, there’s a risk of harmful bacteria, fungi, and toxins finding their way into a person’s bloodstream and causing sepsis—a condition that occurs when infection spreads that may result in life-threatening systemic inflammation. When soldiers are wounded in battle, medics in the field are often working with limited supplies and in less-than-sterile conditions, making wounds even more dangerous.

Tympanogen is developing a novel wound-healing patch that promotes tissue growth and provides a sustained release of antibiotics to reduce the risk of sepsis. A patch able to lower the risk of infection and support tissue repair could significantly improve treatment outcomes in wounded soldiers and reduce combat mortality rates. To gain a better understanding of the characteristics of the patch’s hydrogel material and its drug-release capabilities, Tympanogen sent an experiment to the International Space Station (ISSInternational Space Station) U.S. National Laboratory.

Tympanogen Co-founder and CEO Elaine Horn-Ranney spoke about the company’s spaceflight project at the 2018 ISS Research and Development Conference in a session highlighting medical innovations on the space station. “Through our flight experiment, we’re looking at how microgravityThe condition of perceived weightlessness created when an object is in free fall, for example when an object is in orbital motion. Microgravity alters many observable phenomena within the physical and life sciences, allowing scientists to study things in ways not possible on Earth. The International Space Station provides access to a persistent microgravity environment. affects the structure of these gels and the bulk release of drugs so we can take a look at very basic material behavior,” Horn-Ranney explained during the session. “The goal for us is to start toward the development of a wound-healing model by understanding these material behaviors.”

A Patch that Promotes Healing

Tympanogen’s wound-healing patch contains a hydrogel (an extremely absorbent and porous gel) formed by a network of polymer chains that dissolve in water. The hydrogel has inherent antimicrobial properties and provides controlled release of antibiotics or other drugs. The hydrogel also serves as a scaffold (or support) for healthy tissue growth. The goal is for the patch to destroy pathogens such as bacteria before they can infect healthy cells by releasing a steady dose of antibiotic, thereby protecting against sepsis and promoting wound healing.

For Tympanogen, the first step in developing an effective wound-healing model is to better understand the mechanical and structural properties of their hydrogel material and its rate of drug release. By conducting studies in microgravity conditions onboard the ISS National Lab, the research team can examine the material’s characteristics and ability to release an antibiotic without the influences of gravity-driven phenomena. For example, the team can study drug diffusion from one medium to another without the differences in density between the media affecting diffusion.

In future studies, the ISS could also provide an ideal platform to assess the ability of a wound to heal under stressful conditions. Spaceflight studies have shown that microgravity can negatively affect immune function and the body’s ability to fight pathogens. The stressful microgravity conditions on the ISS can mimic high-stress environments back on Earth such as the battlefield.

Examining Hydrogel in Microgravity

In Tympanogen’s ISS National Lab experiment, the research team sought to determine whether hydrogel polymerized in microgravity differs from hydrogel polymerized on Earth in its mechanical and structural properties. The team also compared the hydrogel’s drug-release capabilities during spaceflight and on the ground.

The team found that although there were differences in the appearance of the spaceflight and ground hydrogels, analysis for stiffness and viscosity revealed that the gels exhibited very similar mechanical properties. The team did note some structural differences between the spaceflight and ground gels in terms of pore size and the structure of the polymer network. The team also found significant differences in the drug-release profiles of the spaceflight and ground hydrogels—both small and large molecules diffused much more slowly in the spaceflight gels than in ground controls.

Tympanogen is continuing development of their wound-healing patch, applying knowledge gained from their spaceflight research. There are currently no wound dressings that both act as a scaffold for tissue regeneration and provide a sustained release of antibiotics directly to a wound. Tympanogen’s patch could one day revolutionize the treatment of combat wounds on the battlefield and could also be an important part of wound healing in astronauts on future long-duration spaceflight missions.