Can Nanotechnology Shine a New Light on Antimicrobial Photodynamic Therapies

Recent developments in light‐controlled therapies (e.g., photodynamic and photother‐ mal therapies) provide promising strategies to prevent and suppress bacterial infections, which are a leading cause of morbidity and mortality. Antibacterial photodynamic ther‐ apy (aPDT) has drawn increasing attention from the scientific society for its potential to kill multidrug‐resistant pathogenic bacteria and for its low tendency to induce drug resistance. In this chapter, we summarize the mechanism of action of aPDT, the pho‐ tosensitizers, as well the current developments in terms of treating Gram‐positive and Gram‐negative bacteria. The chapter also describes the recent progress relating to pho‐ tomedicine for preventing bacterial infections and biofilm formation. We focus on the laser device used in aPDT and on the light‐treatment parameters that may have a strong impact on the results of aPDT experiments. In the last part of this chapter, we survey on the various nanoparticles delivering photoactive molecules, and photoactive‐nanopar‐ ticles that can potentially enhance the antimicrobial action of aPDT.