Smart wound dressing delivers antibiotics on-demand, accelerating healing and reducing resistance

In petri dish experiments, the researchers confirmed that the material only degraded when harmful, beta-lactamase-producing bacteria were present. When only harmless bacteria that do not produce beta-lactamases were present, the material stayed intact and did not lead to antibiotic resistance development over a long-term exposure to the hydrogel dressing.

That selectivity for beta-lactamases is critical, the researchers said. Confirming beta-lactamase specificity means that release of antibiotics only happens in the presence of harmful infection-causing bacteria, and exposure to the healthy skin microbiota can be greatly reduced.

The study also showed that until degradation is triggered, the material holds on tightly to its antibiotic cargo.

"This really is a very stable formulation that doesn't allow the drug to leach out," Shukla said. "It's truly trapped in there until there is a significant amount of beta-lactamase production that can cause hydrogel degradation."

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

Taken together, the results suggest a promising new way to fight wound infections while conserving critical antibiotics. Studies suggest that more than 1 million people worldwide die each year as a result of infections that are resistant to common antibiotics. The problem is expected to get worse, nearing 10 million annual deaths associated with antimicrobial resistance by 2050, if steps are not taken to reduce antibiotic overuse.

"Our findings suggest that these bacterial enzyme-responsive smart hydrogels have the potential to provide targeted, on-demand infection eradication while minimizing unnecessary exposure to antibiotics," the researchers conclude. "By releasing the antibiotic only in the presence of beta-lactamase-producing bacteria, our hydrogel system provides effective treatment while minimizing susceptibility to antibiotic resistance."

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

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