Croconaine conjugated cationic polymeric nanoparticles for NIR enhanced bacterial killing

Area of Science:

• Biomaterials Science
• Antimicrobial Therapy
• Nanotechnology

Background:

• Light-triggered therapies offer noninvasive sterilization with reduced drug resistance and side effects.
• Developing effective antimicrobial agents for broad-spectrum bacterial infections remains a critical challenge.

Purpose of the Study:

• To design and synthesize a functionalized cationic polymer, CR-PQAC, for photothermal enhanced antimicrobial therapy.
• To evaluate the antimicrobial efficacy and biocompatibility of CR-PQAC under near-infrared (NIR) irradiation.

Main Methods:

• CR-PQAC was synthesized incorporating a croconaine bridging agent and quaternary ammonium groups.
• The polymer self-assembled into micellar nanoparticles with strong NIR absorption and high photothermal conversion efficiency (43.8%).
• Antibacterial activity was tested against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria using 808 nm laser irradiation. Cytotoxicity and hemolytic compatibility were assessed.

Main Results:

• CR-PQAC nanoparticles demonstrated significant antibacterial activity against both tested bacterial strains.
• The material exhibited excellent photostability and a high photothermal conversion efficiency.
• CR-PQAC showed negligible dark cytotoxicity and good hemolytic compatibility with mammalian cells.

Conclusions:

• CR-PQAC nanoparticles are effective for photothermal enhanced antimicrobial therapy under NIR irradiation.
• The developed material shows promise as a safe and effective antimicrobial agent for treating bacterial infections.
• Further in vitro and in vivo studies confirm the desirable antibacterial efficacy of CR-PQAC.