Polydopamine-functionalized selenium nanoparticles as an efficient photoresponsive antibacterial platform.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Photodynamic Therapy

Background:

• Antibiotic resistance necessitates novel antibacterial strategies.
• Nanoparticle-based drug delivery systems offer targeted therapeutic potential.
• Photo-activated therapies provide spatiotemporal control over treatment.

Purpose of the Study:

• To design and construct a photoresponsive therapeutic antibacterial platform using polydopamine-functionalized selenium nanoparticles loaded with indocyanine green (Se@PDA-ICG).
• To evaluate the antibacterial efficacy of Se@PDA-ICG against *Staphylococcus aureus* and *Escherichia coli* under laser irradiation.
• To assess the wound healing capabilities of Se@PDA-ICG in a mouse wound infection model.

Main Methods:

• Synthesis and characterization of Se@PDA-ICG nanoparticles.
• In vitro antibacterial assays against *S. aureus* and *E. coli* under 808 nm laser irradiation.
• In vivo study using a mouse wound infection model to evaluate wound closure rates.

Main Results:

• Se@PDA-ICG demonstrated 100% antibacterial activity against *E. coli* and *S. aureus* at 125 μg mL⁻¹ under 808 nm laser irradiation.
• In a mouse model, Se@PDA-ICG treatment resulted in an 88.74% wound closure rate after 8 days, significantly higher than the control group (45.8%).
• The platform effectively killed bacteria and accelerated the wound healing process.

Conclusions:

• Se@PDA-ICG serves as a potent photo-activated antibacterial agent.
• The developed platform significantly enhances wound healing, offering a promising solution for infected wounds.
• Se@PDA-ICG represents a viable candidate material for future biomedical applications in combating bacterial infections.