Smart wound dressings deliver antibiotics for faster healing

In a new study, researchers show that the ingredient can help clear up wound infections faster while reducing the unnecessary use of antibiotics — a major driver of antibiotics. resistance and difficult-to-treat “superbug” infections that claim thousands of lives worldwide each year.

The new material is a smart hydrogel loaded with an antibiotic cargo that can be placed directly on the wound under a bandage. The hydrogel is sensitive to an enzyme produced by a variety of harmful bacteria. When enzymes are present, the hydrogel begins to degrade, releasing the antibiotics trapped inside. But when no harmful bacteria are present, the hydrogel remains intact, safely locking in its antibiotic cargo.

“Antimicrobial resistance is a major problem worldwide, so we need better approaches to how we use antibiotics,” said Anita Shukla, professor at Brown University’s School of Engineering, who led the development of the smart hydrogel.

“We’ve developed a material that releases antibiotics only when harmful bacteria are present, so it limits exposure to antibiotics when they’re not needed but delivers these important drugs when they’re needed.”

for study Science advancesThe researchers put their hydrogel material to the test, showing that it is highly selective for the presence of enzymes produced by common wound infection-causing bacteria, and that it can promote improved infection clearance and wound healing compared to a hydrogel dressing that is commonly used in clinical settings.

Hydrogels are gel-like materials made primarily of water and long, spaghetti-like polymer molecules. The polymers are held together by small molecules called crosslinkers, which keep the hydrogel intact. For this new material, the researchers used a crosslinker that degrades when exposed to enzymes called beta-lactamases, which are produced by a variety of bacteria. This degradation allows the hydrogel structure to disintegrate and release the antibiotic cargo inside.

In petri dish experiments, the researchers confirmed that the material degrades only when harmful, beta-lactamase-producing bacteria are present. When only harmful bacteria that do not produce beta-lactamase, the material remains intact and does not develop antibiotic resistance during long-term exposure to the hydrogel dressing.

That selectivity is important for beta-lactamases, the researchers say. Ensuring beta-lactamase specificity means that antibiotic release occurs only in the presence of harmful infection-causing bacteria, and exposure to healthy skin microbiota can be greatly reduced.

The study also showed that the material held tightly to its antibiotic cargo until degradation was triggered.

“It’s really a very stable formulation that doesn’t allow the drug to leach out,” says Shukla. “It’s really stuck there until there’s a significant amount of beta-lactamase production that can degrade the hydrogel.”

In a series of experiments on mice, the researchers showed that a single application of the hydrogel could completely eradicate the bacterial infection in the abrasion wound. The new material also outperformed an antimicrobial dressing commonly used for both bacterial eradication and wound healing.

Taken together, the results suggest a promising new way to combat wound infections while conserving critical antibiotics. Studies show that infections resistant to common antibiotics kill more than 1 million people worldwide each year. The problem is expected to worsen unless action is taken to reduce antibiotic overuse, with 10 million deaths linked to antimicrobial resistance annually by 2050.

“Our findings suggest that these bacterial enzyme-responsive smart hydrogels have the potential for targeted, on-demand eradication of infections while reducing unnecessary exposure to antibiotics,” the researchers concluded.

“By releasing antibiotics only in the presence of beta-lactamase-producing bacteria, our hydrogel system provides effective treatment by reducing susceptibility to antibiotic resistance.”

The research team has patented the new material and is working towards further advancement of the technology for possible future commercialization.

The work was supported by the Dr Ralph and Marian Falk Medical Research Trust.

Source: Brown University