Antibacterial nanofiber materials activated by light

Area of Science:

• Materials Science
• Biotechnology
• Photochemistry

Background:

• Photodynamic therapy utilizes photosensitizers to generate reactive oxygen species for antimicrobial applications.
• Electrospun nanofibers offer high surface area and tunable properties for advanced material development.

Purpose of the Study:

• To develop and characterize electrospun polymeric nanofibers doped with 5,10,15,20-tetraphenylporphyrin (TPP) photosensitizer.
• To evaluate the light-activated antibacterial efficacy of these nanofiber materials against E. coli.

Main Methods:

• Preparation of TPP-doped nanofibers using polyurethane (PUR), polystyrene (PS), polycaprolactone (PCL), and polyamide 6 (PA6).
• Characterization via microscopy, steady-state, and time-resolved fluorescence and absorption spectroscopy.
• Assessment of antibacterial activity against E. coli under visible light irradiation.

Main Results:

• All TPP-doped nanofiber materials demonstrated light-activated antibacterial activity against E. coli.
• Antibacterial efficacy correlated with oxygen permeability and nanofiber diameter.
• Prolonged antibacterial properties were observed, including a post-irradiation effect in the dark attributed to photogenerated H₂O₂.

Conclusions:

• Electrospun TPP-doped polymeric nanofibers are effective antimicrobial agents activated by visible light.
• The materials exhibit sustained antibacterial action due to singlet oxygen generation and subsequent H₂O₂ photogeneration.
• These findings highlight the potential of TPP-doped nanofibers for developing novel antibacterial surfaces and materials.