Efficacy of photodynamic inactivation against Pseudomonas aeruginosa with pulsed light and CW light excitation

Tohru Yamaguchi, Shunichi Sato, Satoko Kawauchi, Mitsuhiro Terakawa, Nariyoshi Shinomiya, Daizoh Saitoh, Hiroshi Ashida, Minoru Obara

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

We compared methylene blue (MB)-mediated photobactericidal efficacies against Pseudomonas aeruginosa when using nanosecond pulsed light and CW light. In the intensity range of 10-200 mW/cm 2, there was no significant difference between two cases, while photobactericidal efficacy with nanosecond pulsed light was significantly lower than that with CW light at an intensity of 250 mW/cm 2. This is attributable to the saturated absorption of MB molecules due to high peak intensity of nanosecond pulsed light. On the basis of these results, we estimated the depth dependence of bacterial killing, showing that in the skin tissue region deeper than 1.5 mm, photobactericidal efficacy with nanosecond pulsed light was higher than that with CW light. This suggests that the advantage of using high-peak-intensity pulsed light for deep tissue treatment.

Original languageEnglish
Title of host publicationOptical Methods for Tumor Treatment and Detection
Subtitle of host publicationMechanisms and Techniques in Photodynamic Therapy XV
DOIs
Publication statusPublished - 2006 Jun 30
Externally publishedYes
EventOptical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XV - San Jose, CA, United States
Duration: 2006 Jan 212006 Jan 22

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume6139
ISSN (Print)1605-7422

Other

OtherOptical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XV
CountryUnited States
CitySan Jose, CA
Period06/1/2106/1/22

Keywords

  • Cw laser
  • Methylene blue
  • PDT
  • Pseudomonas aeruginosa
  • Pulsed laser
  • Saturated absorption

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Biomaterials
  • Radiology Nuclear Medicine and imaging

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  • Cite this

    Yamaguchi, T., Sato, S., Kawauchi, S., Terakawa, M., Shinomiya, N., Saitoh, D., Ashida, H., & Obara, M. (2006). Efficacy of photodynamic inactivation against Pseudomonas aeruginosa with pulsed light and CW light excitation. In Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XV [61390V] (Progress in Biomedical Optics and Imaging - Proceedings of SPIE; Vol. 6139). https://doi.org/10.1117/12.653078