Photodynamic therapy using intra‐articular photofrin for murine MRSA arthritis: Biphasic light dose response for neutrophil‐mediated antibacterial effect

PDT for murine MRSA arthritis requires appropriate light dosimetry to simultaneously maximize bacterial killing and neutrophil accumulation into the infected site, while too little light does not kill sufficient bacteria and too much light kills neutrophils and damages host tissue as well as bacteria and allows bacteria to grow unimpeded by host defense.