Ethne L Nussbaum1, Facundo Las Heras2, Kenneth P H Pritzker2, Tony Mazzulli3, Lothar Lilge4. 1. Departments of Physical Therapy, Mount Sinai Hospital, University of Toronto, 500 University Ave, Toronto, ON M5G 1X5, Canada. 2. Department of Laboratory Medicine and Pathobiology, Mount Sinai Hospital, University of Toronto, 500 University Ave, Toronto, ON M5G 1X5, Canada. 3. Department of Microbiology, Mount Sinai Hospital, University of Toronto, 500 University Ave, Toronto, ON M5G 1X5, Canada. 4. Department of Medical Biophysics, University of Toronto, 610 University Avenue, Rm. 7-418, Toronto ON M5G 2M9, Canada.
Abstract
BACKGROUND AND OBJECTIVE: Low intensity laser irradiation remains a controversial treatment for non-healing wounds. This study examines the effect of low intensity light on healing of infected skin wounds in the rat. MATERIALS AND METHODS: Wounds on the rat dorsum were inoculated with Pseudomonas aeruginosa. Wounds were irradiated or sham-irradiated three times weekly from day 1 to 19 using 635-nm or 808-nm diode lasers delivering continuous wave (CW) or intensity modulated (3800 Hz) laser radiation, all at radiant exposures of 1 and 20 J/cm2. Wound area and bacterial growth on the wound surface were evaluated three times a week. Histological and immunohistochemical analyses were performed at day 8 and 19. RESULTS: Wounds that were irradiated using a wavelength of 635 nm (1 and 20 J/cm2) or intensity modulated 808-nm laser light at 20 J/cm2 were smaller in area at day 19 than the sham-irradiated controls (achieved significance level=0.0105-0.0208) and were similar to controls in respect of bacterial growth. The remaining light protocols had no effect on wound area at day 19 although they increased Staphylococcus aureus growth across the time line compared with controls (p<0.0001 to p<0.004). CW 808-nm light at 20 J/cm2 significantly delayed half-heal time. Histological and immunohistochemical analyses supported wound closure findings: improved healing was associated with faster resolution of inflammation during the acute phase and increased signs of late repair at day 19. Significant inflammation was seen at day 19 in all irradiated groups regardless of radiant exposure, except when using 635 nm at 1 J/cm2. CONCLUSIONS: Red light improved healing of wounds. Only one 808-nm light protocol enhanced healing; lack of benefit using the remaining 808-nm light protocols may have been due to stimulatory effects of the light on S. aureus growth.
BACKGROUND AND OBJECTIVE: Low intensity laser irradiation remains a controversial treatment for non-healing wounds. This study examines the effect of low intensity light on healing of infected skin wounds in the rat. MATERIALS AND METHODS: Wounds on the rat dorsum were inoculated with Pseudomonas aeruginosa. Wounds were irradiated or sham-irradiated three times weekly from day 1 to 19 using 635-nm or 808-nm diode lasers delivering continuous wave (CW) or intensity modulated (3800 Hz) laser radiation, all at radiant exposures of 1 and 20 J/cm2. Wound area and bacterial growth on the wound surface were evaluated three times a week. Histological and immunohistochemical analyses were performed at day 8 and 19. RESULTS: Wounds that were irradiated using a wavelength of 635 nm (1 and 20 J/cm2) or intensity modulated 808-nm laser light at 20 J/cm2 were smaller in area at day 19 than the sham-irradiated controls (achieved significance level=0.0105-0.0208) and were similar to controls in respect of bacterial growth. The remaining light protocols had no effect on wound area at day 19 although they increased Staphylococcus aureus growth across the time line compared with controls (p<0.0001 to p<0.004). CW 808-nm light at 20 J/cm2 significantly delayed half-heal time. Histological and immunohistochemical analyses supported wound closure findings: improved healing was associated with faster resolution of inflammation during the acute phase and increased signs of late repair at day 19. Significant inflammation was seen at day 19 in all irradiated groups regardless of radiant exposure, except when using 635 nm at 1 J/cm2. CONCLUSIONS: Red light improved healing of wounds. Only one 808-nm light protocol enhanced healing; lack of benefit using the remaining 808-nm light protocols may have been due to stimulatory effects of the light on S. aureus growth.
Authors: Ge Zhao; Phillip C Hochwalt; Marcia L Usui; Robert A Underwood; Pradeep K Singh; Garth A James; Philip S Stewart; Philip Fleckman; John E Olerud Journal: Wound Repair Regen Date: 2010-08-19 Impact factor: 3.617
Authors: Ethne L Nussbaum; Tony Mazzulli; Kenneth P H Pritzker; Facundo Las Heras; Fang Jing; Lothar Lilge Journal: Lasers Surg Med Date: 2009-07 Impact factor: 4.025
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Authors: Andrezza Maria Côrtes Thomé Lima; Luiz Philippe da Silva Sergio; Larissa Alexsandra da Silva Neto Trajano; Bianca Paschoal de Souza; João Pedro da Motta Mendes; Adriano Fonseca Ribeiro Cardoso; Caroline Pisa Figueira; Beatriz Dos Anjos Tavares; Daniella Sousa Figueira; André Luiz Mencalha; Eduardo Tavares Lima Trajano; Adenilson de Souza da Fonseca Journal: Lasers Med Sci Date: 2019-08-31 Impact factor: 3.161
Authors: João Paulo Mardegan Issa; Bianca Ferreira Trawitzki; Edilson Ervolino; Ana Paula Macedo; Lothar Lilge Journal: Lasers Med Sci Date: 2017-05-30 Impact factor: 3.161