Antifungal efficacy of lasers against dermatophytes and yeasts in vitro. (September 2013)

• Record Type: Journal Article
• Authors: Paasch, Uwe; Mock, Andrea; Grunewald, Sonja; Bodendorf, Marc O.; Kendler, Michael; Seitz, Anna-Theresa; Simon, Jan C.; Nenoff, Pietro
• Is Part Of: International journal of hyperthermia. Volume 29:Number 6(2013)
• Page Start: 544
• Page End: 550
• Publication Date: 2013-09
• Subjects: Thermotherapy -- Periodicals; 615.832
• DOI: 10.3109/02656736.2013.823672
• Languages: English
• ISSNs: 0265-6736

Abstract

<abstract> <title>Abstract</title> <p> <italic>Purpose</italic>: Approximately 2–13% of the world population suffers from onychomycosis. Recently, lasers have been introduced for treatment. However, no effect was found with <italic>in vitro</italic> laser irradiation of pathogens on agar plates. This study aimed to investigate the efficacy of laser irradiation against fungi using an alternative <italic>in vitro</italic> approach.</p> <p> <italic>Materials and methods</italic>: Lasers of 808, 980 and 1064 nm were used to heat cell culture media and a nail clipping. <italic>Trichophyton rubrum. T. interdigitale. Microsporum gypseum. Candida albicans. C. parapsilosis</italic>, and <italic>C. guilliermondii</italic> species were subcultured and subjected to laser treatments (808/980 nm: 9–27 J/cm<sup>2</sup>, 6 ms, 12 × 12 or 12 × 50 mm and 1064 nm: 50–240 J/cm<sup>2</sup>, 90 ms, 5–10 mm). After irradiation, the fungal elements were transferred onto agar plates using conventional and Drigalski spatulas and were incubated for 6 days.</p> <p> <italic>Results</italic>: The highest increase in temperature was found using a 980-nm laser with a pulse duration of 6 ms and a fluence of 27 J/cm<sup>2</sup>. The histology work-up revealed a dissection of the nail plate from the nail bed tissue after laser irradiation. Growth inhibition was only found for <italic>C. guilliermondii</italic> and <italic>T. interdigitale</italic>. All other pathogens presented only reduced growth, and <italic>C. albicans</italic> growth was unaffected.</p> <p> <italic>Conclusions</italic>: This study demonstrates a clear thermal effect for linear scanning 980-nm and long-pulsed 1064-nm laser systems on either nail clippings or cell culture media. Complete pathogen growth impairment was achieved if temperatures were measured above 50 °C. The results for the 1064-nm system were almost comparable to 980 nm results.</p> </abstract>