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LED-Based In Vitro Screening for Assessing Photoactivable Molecules in Bacterial Photodynamic Inactivation
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In vitro inactivation of Enterococcus faecalis with a led device
S D'Ercole1, G Spoto2, P Trentini2
1Microbiology and Paediatric Dentistry Unit, Department of Medical, Oral and Biotechnological Sciences, University of Chieti, Via dei Vestini 31, 66013, Italy.
Journal of Photochemistry and Photobiology. B, Biology
|April 25, 2016
Summary
Near-infrared LED (NIR-LED) irradiation effectively reduces Enterococcus faecalis viability. Combining NIR-LED with sodium hypochlorite (NaOCl) achieved total bacterial inhibition, demonstrating a potent antibacterial effect.
Area of Science:
- Biomedical Engineering
- Microbiology
- Photomedicine
Background:
- Non-coherent light-emitting diodes (LEDs) have diverse clinical applications, but their bactericidal effects remain largely unexamined.
- No prior studies have investigated the impact of Near-Infrared LED (NIR-LED) irradiation on bacterial viability.
Purpose of the Study:
- To determine the antibacterial activity of 880-nm LED irradiation against Enterococcus faecalis suspensions.
- To compare the efficacy of NIR-LED treatment alone, sodium hypochlorite (NaOCl) alone, and their combined use.
Main Methods:
- Preliminary tests assessed the influence of irradiation distance, energy density, time, and photosensitizers on LED antimicrobial effects.
- Bacterial viability was quantified by colony-forming units per milliliter (CFU/mL) post-treatment.
- Statistical analysis included ANOVA and Bonferroni post hoc tests with a significance level of 5%.
Main Results:
- 880-nm LED irradiation significantly reduced E. faecalis viability in vitro.
- Concurrent treatment with NIR-LED and 1% NaOCl for 5 minutes resulted in complete inhibition of E. faecalis.
- No statistically significant differences in antimicrobial activity were observed when varying irradiation distance, energy density, irradiation time, or adding toluidine blue O.
Conclusions:
- 880-nm LED irradiation possesses significant antibacterial properties against E. faecalis.
- Combining NIR-LED with NaOCl offers a highly effective strategy for bacterial eradication.
- LED parameters like distance, energy density, and time, as well as the addition of TBO, did not significantly alter the observed antimicrobial effects within the tested ranges.
