I presume this is intended for wounds in areas with poor circulation, like a diabetic foot or a walled off abscess. The bloodstream is damn good at delivering antibiotics and immune cells to infected areas.
One of the problems is that the bloodstream is good at delivering antibiotics everywhere, which encourages resistance and many of the side effects of antibiotics.
That, plus wounds with poor circulation, or as the article notes, infections that are protected by biofilms.
