Bacterial bioflms are made up of colonies of bacteria that stick together by building up a slimy polymer matrix. Unfortunately, topically applied antibiotics and other medications have difficulty penetrating that matrix, so they can't reach the infected tissue underneath.
As a result, doctors will often peel off the biofilms before treating the wounds. Not only is this painful to the patient, but some healthy tissue will often come off along with the biofilm, setting back the healing process. With these limitations in mind, scientists at Indiana's Purdue University have developed a biodegradable polymer composite patch with an array of tiny medication-laden "microneedle" studs on its underside.
When the patch is applied to a chronic wound, those microneedles penetrate the biofilm and absorb fluid from the tissue underneath. This causes them to harmlessly dissolve, releasing their medication into that tissue.