Related Experiment Video
Updated: Aug 6, 2026
05:13
LED-Based In Vitro Screening for Assessing Photoactivable Molecules in Bacterial Photodynamic Inactivation
Published on: January 24, 2025
Cellulose Acetate Nanoparticles as Eco-Friendly Photosensitizers for Antimicrobial Photodynamic Inactivation
Raphael S Flores1, Gabriella Miessi1, Priscila S Cavalheri1
1Optics and Photonics Group, Institute of Physics, Federal University of Mato Grosso do Sul, P.O. Box 549, Campo Grande, Mato Grosso do Sul 79070-900, Brazil.
ACS Omega
|July 24, 2026
Summary
Cellulose acetate nanoparticles (NPs-CA) show promise as eco-friendly photosensitizers for antimicrobial photodynamic inactivation. These safe, light-activated nanoparticles effectively inactivated E. coli, offering a sustainable alternative for combating resistant bacteria.
Area of Science:
- Materials Science
- Biotechnology
- Environmental Science
Background:
- Antimicrobial resistance (AMR) is a growing global health threat, necessitating novel therapeutic strategies.
- Conventional antibiotics face limitations due to resistance development.
- Sustainable and eco-friendly alternatives are crucial for effective antimicrobial treatments.
Purpose of the Study:
- To develop and assess cellulose acetate nanoparticles (NPs-CA) as photosensitizers for antimicrobial photodynamic inactivation (aPDI).
- To evaluate the efficacy of NPs-CA against specific bacterial strains and assess their safety profile.
Main Methods:
- Cellulose acetate nanoparticles (NPs-CA) were synthesized using nanoprecipitation.
- Characterization included UV-vis, SEM, and DLS for morphology and photophysical properties.
- Antimicrobial efficacy was tested against *Escherichia coli* and *Staphylococcus aureus* using aPDI.
- ROS generation and acute toxicity were evaluated using DHE and *Artemia* sp. assays, respectively.
Main Results:
- Synthesized NPs-CA were spherical with a hydrodynamic diameter of 268 ± 8 nm.
- NPs-CA absorbed visible light at 450 nm and generated reactive oxygen species (ROS) upon irradiation.
- Significant *E. coli* inactivation (>3 log10 CFU reduction) was achieved at 500 ppm, with complete photoinactivation at 1000 ppm under blue light.
- *S. aureus* showed limited sensitivity to the aPDI treatment.
- Toxicity assays indicated a non-toxic profile (LC50 = 320.56 ppm, TU < 0.4).
Conclusions:
- NPs-CA function as effective light-activated photosensitizers for inactivating *E. coli*.
- The developed cellulose-based nanomaterials demonstrate safety in ecotoxicological assessments.
- NPs-CA present a sustainable and biocompatible platform for antimicrobial photodynamic therapy, particularly against Gram-negative bacteria.
