PhotoCORM-based nanomaterials for antimicrobial therapeutics

Antibiotic-resistant bacteria are threatening a worldwide resurgence of deadly infections in men and animals. This growing global concern is accompanied by an ever-increasing void in the arsenal of clinicians. Alternative solutions are urgently needed. Over the last decade, carbon monoxide (CO) has been identified as an inhibitor of bacteria proliferation and a potent antibacterial agent. It diffuses freely through membranes and may be particularly active when generated close to some bacteria. However, at high concentrations, CO is an anthropogenic poison, quite dangerous to handle as a gas. For this reason, there has been great interest in photochemically CO-releasing molecules (photoCORMs), which can deliver CO in a timely- and spatially controlled way when excited by light. Remarkably, photoCORMs have proved to be much more efficient bactericides than CO gas alone, possibly due to the concomitant generation of reactive oxygen species (ROS), and to a direct bactericidal effect of these molecules. Therefore, they have raised high hopes as novel antimicrobial agents in the post-antibiotic era [1].