Antimicrobial Photodynamic Therapy for the Remote Eradication of Bacteria

The emergence of multi-drug resistant bacteria strains has been an uphill battle in modern healthcare worldwide, due to the increasing difficulty of killing them. The evolving pathogenicity of bacteria has led to researchers searching for more effective antimicrobial therapeutics to successfully eliminate them without undesirable consequences to the human body. In recent years, antimicrobial photodynamic therapy (APDT), an obsolete technique for cancer treatments, has been reported to eradicate bacteria and biofilm-related infections. The principle of antimicrobial photodynamic therapy solely relies on the photosensitizers (PSs) generating reactive oxygen species, in the presence of oxygen and light, to destroy pathogens. Thus, it can target a broad spectrum of microorganisms, owing to the indirect interaction between PSs and the bacteria, resulting in the less likelihood for the development of drug resistant bacteria strains. This review will focus on the recent progress of APDT in the last five years and some future perspectives of APDT. The mechanism of APDT against bacteria and biofilms, various PSs used for APDT, and some common multidrug-resistant bacteria strains will be briefly introduced. The reported in vivo applications of APDT in the several types of bacterial infections that includes periodontitis, wound infections, keratitis, endophthalmitis and tuberculosis in the last five years will be summarized in detail.