Cell lineage responses to photobiomodulation therapy

Area of Science:

• Biomedical Engineering
• Cell Biology
• Photomedicine

Background:

• Photobiomodulation (PBM) therapy utilizes light to stimulate cellular processes, showing promise in wound healing and tissue regeneration.
• Current PBM protocols often overlook the distinct cellular responses within target tissues, potentially impacting treatment outcomes.

Purpose of the Study:

• To determine the maximal laser dose thresholds for oral keratinocytes and fibroblasts.
• To investigate the differential responses of these cell types to near-infrared laser therapy.
• To explore the role of reactive oxygen species (ROS) and catalase in cellular sensitivity to PBM.

Main Methods:

• In vitro exposure of oral keratinocytes and fibroblasts to varying near-infrared laser irradiances.
• Measurement of cell survival and reactive oxygen species (ROS) production.
• Assessment of catalase expression and activity, with induced catalase activity using melatonin.

Main Results:

• Oral keratinocytes demonstrated higher sensitivity to laser therapy than fibroblasts, with lower maximal tolerance doses.
• Increased ROS levels were observed in keratinocytes post-laser treatment, inversely correlating with basal catalase expression.
• Melatonin-induced catalase activity significantly enhanced keratinocyte survival against phototoxic laser doses.

Conclusions:

• Clinical PBM dosing strategies should consider the differential sensitivities of individual cell types, such as keratinocytes and fibroblasts.
• Accounting for cell-specific responses can optimize the safety and efficacy of PBM therapies.
• Targeting cellular mechanisms like catalase activity may mitigate phototoxicity and improve PBM treatment outcomes.