Theoretic, Experimental, Clinical Bases of the Water Oscillator Hypothesis in Near-Infrared Photobiomodulation

Huang

Biochimica et Biophysica Acta (BBA) - General Subjects

et al. 2017

153

Photobiomodulation (PBM) using red or near-infrared (NIR) light has been used to stimulate the proliferation and differentiation of adipose-derived stem cells. The use of NIR wavelengths such as 810nm is reasonably well accepted to stimulate mitochondrial activity and ATP production via absorption of photons by cytochrome c oxidase. However, the mechanism of action of 980nm is less well understood. Here we study the effects of both wavelengths (810 nm and 980 nm) on adipose-derived stem cells in vitro. Both wavelengths showed a biphasic dose response, but 810nm had a peak dose response at 3J/cm2 for stimulation of proliferation at 24 hours, while the peak dose for 980nm was 10–100 times lower at 0.03 or 0.3 J/cm2. Moreover, 980nm (but not 810nm) increased cytosolic calcium while decreasing mitochondrial calcium. The effects of 980nm could be blocked by calcium channel blockers (capsazepine for TRPV1 and SKF96365 for TRPC channels), which had no effect on 810nm. To test the hypothesis that the chromophore for 980nm was intracellular water, which could possibly form a microscopic temperature gradient upon laser irradiation, we added cold medium (4°C) during the light exposure, or pre-incubated the cells at 42°C, both of which abrogated the effect of 980nm but not 810nm. We conclude that 980nm affects temperature-gated calcium ion channels, while 810nm largely affects mitochondrial cytochrome c oxidase.

Section: Discussionmentioning

confidence: 99%

Photobiomodulation of human adipose-derived stem cells using 810 nm and 980 nm lasers operates via different mechanisms of action

Huang

Biochimica et Biophysica Acta (BBA) - General Subjects

et al. 2017

153

“…39 The chromophore in these situations is almost certainly water, possible present in biological membranes in some nanostructured form, that is different from bulk water allowing biological effects without gross heating of the tissue. 94,95 It is at present not clear at which wavelength CCO absorption ceases and water absorption commences to be important.…”

Section: Light Sources and Dosimetrymentioning

confidence: 99%

The Nuts and Bolts of Low-level Laser (Light) Therapy

et al. 2011

Soon after the discovery of lasers in the 1960s it was realized that laser therapy had the potential to improve wound healing and reduce pain, inflammation and swelling. In recent years the field sometimes known as photobiomodulation has broadened to include light-emitting diodes and other light sources, and the range of wavelengths used now includes many in the red and near infrared. The term “low level laser therapy” or LLLT has become widely recognized and implies the existence of the biphasic dose response or the Arndt-Schulz curve. This review will cover the mechanisms of action of LLLT at a cellular and at a tissular level and will summarize the various light sources and principles of dosimetry that are employed in clinical practice. The range of diseases, injuries, and conditions that can be benefited by LLLT will be summarized with an emphasis on those that have reported randomized controlled clinical trials. Serious life-threatening diseases such as stroke, heart attack, spinal cord injury, and traumatic brain injury may soon be amenable to LLLT therapy.

Photomedicine - Advances in Clinical Practice

“…In another study, laser irradiation of mitochondria increased cytochrome c oxidase activity, polarographically measured levels of oxygen uptake, and subsequent ATP production [56]. Many other in vitro and in vivo studies of laser-induced cell growth have reported changes in cytochrome c oxidase activity and ATP production following irradiation [57][58][59][60][61][62][63][64][65].…”

Section: Cytochrome C Oxidasementioning

confidence: 99%

Biological Function of Low Reactive Level Laser Therapy (LLLT)

Kubota¹,

Ishihara²

2017

Low reactive level laser therapy (LLLT) and photobiomodulation are mainly focused on the activation of intracellular or extracellular photoabsorbable molecule (chromophore) and the initiation of cellular signaling using low power lasers and lights. Over the past 40 decades, a number of basic and clinical researches were reported that the laser therapy had the potential to improve wound healing and reduce pain and inflammation. In recent years, the term "LLLT" has become widely recognized. In this review, the mechanisms of action of LLLT at a cellular level are described. Finally, our recent research results that LLLT enhanced the cells differentiation are also described.