Recent Advances in Metal Complexes for Antimicrobial Photodynamic Therapy

Area of Science:

• Medicinal Chemistry
• Photochemistry
• Microbiology

Background:

• Antimicrobial resistance (AMR) is a critical global health threat, causing over a million deaths annually.
• Novel therapeutic strategies are urgently needed to combat drug-resistant pathogens.
• Antimicrobial photodynamic therapy (aPDT) offers a light-activated approach with high selectivity to kill microbes.

Purpose of the Study:

• To review recent advancements in small-molecule metal complex photosensitizers (PSs) for aPDT.
• To highlight the potential of metal complexes in overcoming AMR.
• To consolidate research on metal-based PSs for aPDT applications in the last five years.

Main Methods:

• Literature review focusing on studies published within the last five years.
• Analysis of metal complexes investigated as photosensitizers in aPDT.
• Synthesis and characterization of metal complex photosensitizers (as reported in the literature).

Main Results:

• Metal complexes exhibit favorable optoelectronic properties for aPDT applications.
• Several metal-based PSs have demonstrated efficacy against various microbial strains.
• The generation of reactive oxygen species (ROS) by activated PSs is the primary mechanism of action.

Conclusions:

• Small-molecule metal complexes represent a promising class of photosensitizers for aPDT.
• aPDT utilizing metal complexes offers a viable strategy to combat AMR by circumventing existing resistance mechanisms.
• Continued research into metal complex design and aPDT protocols is essential for clinical translation.