Antimicrobial photodynamic therapy: from basis to clinical applications

Antimicrobial photodynamic therapy (APDT) combines the use of light with a photosensitizer (PS) and oxygen to kill microbial cells. Even though this technique was first reported in the beginning of the 20th century, APDT never took off as antimicrobial chemotherapy did. However, microbial resistance to chemotherapy is currently expanding in faster rates than drug discovery. Therefore, introduction of therapeutic alternatives that bypass mechanisms of drug resistance now presents an urgent status. Fortunately, the scientific and technological development related to APDT made it far more feasible for mainstream clinical applications. Our research group has been working on mechanisms and applications of APDT for almost 20 years. We have already reported that successful APDT results depend on a number of factors, such as PS and light parameters, cell type, and oxygen abundance, among others. We have also demonstrated that APDT is an effective adjuvant in endodontics and periodontics and can be a non-invasive treatment for caries, candidiasis and cutaneous leishmaniasis. In Veterinary Medicine, we have reported effective treatment for penguin pododermatitis, snake stomatitis and dog otitis. This presentation will give an integrated perspective from the basic APDT mechanisms, preclinical and clinical trials to protocol optimization and future perspectives.