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In vitro study on the effects of photodynamic inactivation using methyl pheophorbide a, PhotoMed, PhotoCure, and
Keun-Dol Yook1, Ji-Won Kim2, Young-Kyu Song3
1Department of Clinical Laboratory Science, Daejeon Health Institute of Technology, Daejeon, Republic of Korea.
Background:
Candida albicans (C. albicans) is the most common fungal pathogen that causes clinical infections in humans. This study aimed to evaluate the effects of photodynamic inactivation (PDI) using a 660 nm diode laser along with methyl pheophorbide a, PhotoMed, and PhotoCure as photosensitizer for analyzing the viability of in vitro inactivation of C. albicans Methods: In the PDI group, 20 μL of C. albicans suspension and 20 μL of photosensitizer were inoculated in a 90 mm petri dish (63.6 cm2). The samples were placed in an incubator at 37 °C for 30 min, and then they were irradiated with light (660 nm diode laser, 3 J/cm2). After laser irradiation, the cells were stored for 48 h at 37 °C in an incubator with 5% CO2, and the number of colonies was counted.
Results:
The highest reduction in the number of colony-forming units per milliliter (CFU/mL) after PDI was observed in the presence of methyl pheophorbide a and PhotoMed, followed by PhotoCure. One-way analysis of variance (ANOVA) demonstrated a significant inhibition (F = 384.717; P < 0.05) for each PDI.
Conclusions:
In this study, we demonstrated that the application of PDI to C. albicans using methyl pheophorbide a and PhotoMed resulted in 100% death rates. PDI could be a treatment method because conventional antifungals have limited effects, and they may not eliminate C. albicans completely.
Insights
Photodynamic inactivation (PDI) with methyl pheophorbide a and PhotoMed effectively eliminated Candida albicans in vitro. This PDI approach offers a promising alternative to conventional antifungals with limited efficacy.
Area of Science:
- Microbiology
- Biophysics
- Photomedicine
Background:
- Candida albicans is a common human fungal pathogen.
- Conventional antifungal treatments can be limited in their effectiveness.
- There is a need for alternative methods to eradicate C. albicans.
Purpose of the Study:
- To evaluate the efficacy of photodynamic inactivation (PDI) against Candida albicans.
- To assess the effectiveness of specific photosensitizers (methyl pheophorbide a, PhotoMed, PhotoCure) with a 660 nm diode laser.
Main Methods:
- C. albicans cultures were treated with photosensitizers.
- Samples were incubated and then irradiated with a 660 nm diode laser at 3 J/cm².
- Colony-forming units (CFU/mL) were counted after incubation.
Main Results:
- Photodynamic inactivation (PDI) significantly inhibited C. albicans growth (P < 0.05).
- Methyl pheophorbide a and PhotoMed demonstrated the highest reduction in CFU/mL.
- 100% death rates of C. albicans were achieved with methyl pheophorbide a and PhotoMed.
Conclusions:
- PDI using methyl pheophorbide a and PhotoMed is highly effective for in vitro C. albicans inactivation.
- PDI presents a viable alternative treatment strategy for C. albicans infections.
- This method may overcome limitations associated with conventional antifungal therapies.
