A flexible biodegradable microneedle array contains calcium peroxide. The microneedles pierce the biofilm layer of a wound and deliver the medicine to oxygenate the tissue and effectively eradicate biofilm infections on the wound. (Credit: Purdue University photo/Vincent Walter)

A flexible polymer composite microneedle array can overcome the physicochemical bacterial biofilm present in chronic, nonhealing wounds and deliver both oxygen and bactericidal agents simultaneously.

The biofilm acts as a shield, hindering antibiotics from reaching infected cells and tissues. When these microneedles pierce through the shield, they absorb the fluid underneath and dissolve, which delivers the antibiotic directly to the ulcerated cells and tissues.

The traditional method to bypass biofilm is for physicians to peel it off, which is painful to patients and doesn't discriminate unhealthy tissue from healthy tissue. The microneedles don’t cause pain because they are not long enough to touch nerve endings in the foot. In this study, the team assessed the microneedles on ex vivo porcine wound models. In fewer than five minutes, the microneedles dissolved, the antibiotic was delivered, and the patch was removed.