Two-Photon-Active Organotin(IV) Complexes for Antibacterial Function and Superresolution Bacteria Imaging

Area of Science:

• Medicinal Chemistry
• Biomedical Science
• Materials Science

Background:

• Two-photon absorption (TPA) antibacterial agents are crucial for advanced biomedical applications.
• Organometallic compounds offer unique properties for therapeutic development.

Purpose of the Study:

• To design and synthesize novel coumarin-based organotin complexes with TPA properties.
• To evaluate the antibacterial efficacy and mechanism of action of these complexes.
• To explore their potential in superresolution bacterial imaging and diagnostics.

Main Methods:

• Synthesis and characterization of two novel organotin complexes (HLSn1 and HLSn2).
• Determination of two-photon absorption cross-sections in the near-infrared region.
• Minimum inhibitory concentration (MIC) assays against Gram-negative (Escherichia coli) and Gram-positive (Bacillus subtilis) bacteria.
• Two-photon imaging and superresolution microscopy to investigate cellular interactions and mechanisms.

Main Results:

• Both HLSn1 and HLSn2 exhibited significant two-photon activity.
• HLSn1 demonstrated potent antibacterial activity against E. coli and B. subtilis, with a notably low MIC for B. subtilis (2 μg mL⁻¹).
• Mechanism involves interaction with bacterial membranes, generation of reactive oxygen species (ROS), and subsequent cell death, visualized via superresolution imaging.

Conclusions:

• The synthesized organotin complexes possess promising two-photon properties and potent antibacterial capabilities.
• HLSn1 is a potential candidate for superresolution bacterial imaging, diagnostics, and treatment of infections.
• This research opens avenues for developing advanced antimicrobial agents and imaging tools.