The effects of low power laser light at 661 nm on wound healing in a scratch assay fibroblast model

Abstract

Wound treatment, especially for chronic and infected wounds, has been a permanent socio-economical challenge. This study aimed to investigate the ability of red light at 661 nm to accelerate wound healing an in vitro wound model using 3T3 fibroblasts. The purpose is further specified in clarifying the mechanisms of wound closure by means of intracellular ROS production, proliferation and migration of cells, and cellular orientation. Illumination effects of red light from a diode laser (661 nm) at different doses on 3T3 cell viability was assessed via MTT assay and tested in a scratch wound model. Wound closure rates were calculated by image analysis at 0, 24, and 48 h after laser treatment. ROS production was monitored and quantified immediately and 24 h after the treatment by fluorescence microscopy. Cellular orientation was quantified by image analysis. No phototoxic energy doses used and increased cell viability in most of the groups. Scratch assay revealed an energy interval of 3 – 4.5 J/cm2 that promote higher wound healing rate 24 h post treatment. An increase in ROS production was also observed 24 h post irradiation higher in the group with the highest wound healing rate. Also, cellular orientation toward the margin of the wound was observed and quantified after irradiation. Low power laser light at 661 nm activated both the migration and proliferation in the in vitro model used, providing evidence that it could also accelerate wound healing in vivo. Also, ROS production and cellular orientation seem to play an important role in wound healing process.

Photobiomodulation and Wound Healing: Low-Level Laser Therapy at 661 nm in a Scratch Assay Keratinocyte Model

“…In another study conducted also in our laboratory [ 31 ], with the same laser source and the same experimental conditions using 3T3 fibroblasts instead of keratinocytes, the wound closure was faster compared to our scratch models. All wounds, including controls, were totally closed within 2 days, whereas in keratinocytes total wound closure was observed in only 2 experimental groups 3 days after irradiation.…”

Fabrication of novel nanofiber composed of gelatin/alginate with zirconium oxide NPs regulate orthodontic progression of cartilage degeneration on Wnt/β-catenin signaling axis in MC3T3-E1 cells

“…In addition, the group exposed to 10 mW/cm 2 for 8 min (4.8 J/cm 2 ) had a significantly higher wound healing rate 24 h later compared to the other groups. Wound closure in the irradiated groups was nearly identical to that in the control group 48 h after the treatment ended [ 26 ]. A reliable scratch apparatus for conducting in vitro scratch assays with high levels of consistency and repeatability.…”

“…Previous research suggested that mandible advancement (MA) appliances might deliver effective orthopaedic forces to the inframaxillary condyle, and modify cartilage development then bone construction. However, the primary diseased alteration in TMJ-OA is the degradation of condylar cartilage due to overload stress [ 26 ]. As a result, TMJ OA contributes to the overloading of articular cartilage and the subchondral bone.…”

Glucose Improves the Efficacy of Photobiomodulation in Changing ATP and ROS Levels in Mouse Fibroblast Cell Cultures

“…One feature that was clear from all of our measures, but particularly from the cell viability test, was that the dosage of the photobiomodulation treatment at 15 mW/cm 2 for 120 s twice a day over 24 h for 2 days was not detrimental to the fibroblast cells; this dosage regime equated to 7.2 J/cm 2 . Many previous in vitro studies have also reported that photobiomodulation is not detrimental to cells, whether they be fibroblasts [37][38][39][40][41] or neurones [42][43][44], across a wide range of doses, for example from 3 to 50 J/cm 2 . Our dosage regime of 7.2 J/cm 2 was well within this range and confirms the widely held view that photobiomodulation is an entirely safe treatment option, with little or no evidence for cytotoxicity, across an extensive range of therapeutic dose applications [2].…”