In vitro effects of 635 nm photobiomodulation under hypoxia/reoxygenation culture conditions

Early cases of acute infectious respiratory syndrome treated with photobiomodulation, diagnosis and intervention: Two case reports

“…A neat increase of 1.6 times in local tissue oxygen tension was previously described with HeNe laser (633 nm, 1 mW, 10 mn irradiation), without production of singlet oxygen in the process of molecular oxygen photodissociation from haemoglobin 34 . A parallel can be drawn with the findings of a study that evaluated in vitro the effects of RL 635 nm on cellular function in hypoxia and reoxygenation conditions, concluding enhanced mitochondrial activity when ATP levels were challenged: weaker initial ATP inducing higher stimulative effects 35,36 . Recent investigations from the French National Institute for Medical Research (INSERM) have identified at electron microscopy 3.7 million cell‐free functional mitochondria per ml of plasma in human blood acting as cellular respiration organelles and potential diagnostic biomarkers 37 .…”

“…34 A parallel can be drawn with the findings of a study that evaluated in vitro the effects of RL 635 nm on cellular function in hypoxia and reoxygenation conditions, concluding enhanced mitochondrial activity when ATP levels were challenged: weaker initial ATP inducing higher stimulative effects. 35,36 Recent investigations from the French National Institute for Medical Research (INSERM) have identified at electron microscopy 3.7 million cell-free functional mitochondria per ml of plasma in human blood acting as cellular respiration organelles and potential diagnostic biomarkers. 37 An earlier study discussed the correspondence between platelet mitochondrial respiration and impaired ATP levels in depressed individuals, describing erythrocytes illumination with RL as a possible systemic therapy in depression.…”

Interplay between epithelial and mesenchymal cells unveils essential proinflammatory and pro‐resolutive mediators modulated by photobiomodulation therapy at 660 nm

“…At last, our VEGF mRNA analyses showed a remarkable boost at 5 J/cm 2 (17 times greater than the controls)—exclusively in the co‐culture system—corroborating the previously demonstrated proangiogenic nature of PBMT 8,15,46–48 . Angiogenesis involves the growth of new vessels, where VEGF stands as a key pro‐angiogenic modulator for endothelial cells 49 .…”

“…9 At last, our VEGF mRNA analyses showed a remarkable boost at 5 J/cm 2 (17 times greater than the controls)-exclusively in the coculture system-corroborating the previously demonstrated proangiogenic nature of PBMT. 8,15,[46][47][48] Angiogenesis involves the growth of new vessels, where VEGF stands as a key pro-angiogenic modulator for endothelial cells. 49 In recent years, much attention has been drawn also to the role of pericytes in vascular function, as they interact not only with endothelial cells but with epithelial, haematopoietic, and mesenchymal cells promoting wound healing and tissue regeneration.…”

“…Mimicking in vitro conditions that resemble the interplay between epithelial and mesenchyme components could help understand the effectual role of light stimuli in an injured milieu. Considering that PBMT is known to produce stimulatory effects mostly when cells and tissues are under any physical or chemical stress, [14][15][16] our goal was to comprehensively analyse light stimuli at the energy densities of 1, 5, and 50 J/cm 2 (at 660 nm) on essential functions of KC cells cultivated under serum-deprived conditions. We further validated the PBMT effects at 5 J/cm 2 parameters on more complex microenvironments using the co-culture and ex vivo models.…”