Aging Is a Sticky Business

Sommer, Andrei P.

doi:10.1089/pho.2017.4393

Cited by 5 publications

(3 citation statements)

References 19 publications

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“…When thawing, the water layer temperature is lower than normal, which increases the viscosity 34 . Higher viscosity during ATP synthesis decreases ATP generation 35 , 36 . Thus, the viscosity around the ATP synthase can increase due to the low temperature of the thawing cell, resulting in a reduced ATP generation rate relative to normal cells.…”

Section: Discussionmentioning

confidence: 99%

Photobiomodulation as an antioxidant substitute in post-thawing trauma of human stem cells from the apical papilla

Choi

Baik

Jeong

et al. 2021

Sci Rep

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Cryopreservation, the most common method of preserving stem cells, requires post-processing because it produces trauma to the cells. Post-thawing trauma typically induces cell death, elevates reactive oxygen species (ROS) concentration, and lowers mitochondrial membrane potential (MMP). Although this trauma has been solved using antioxidants, we attempted to use photobiomodulation (PBM) instead of chemical treatment. We used a 950-nm near-infrared LED to create a PBM device and chose a pulsed-wave mode of 30 Hz and a 30% duty cycle. Near-infrared radiation (NIR) at 950 nm was effective in reducing cell death caused by hydrogen peroxide induced-oxidative stress. Cryodamage also leads to apoptosis of cells, which can be avoided by irradiation at 950 nm NIR. Irradiation as post-processing for cryopreservation had an antioxidant effect that reduced both cellular and mitochondrial ROS. It also increased mitochondrial mass and activated mitochondrial activity, resulting in increased MMP, ATP generation, and increased cytochrome c oxidase activity. In addition, NIR increased alkaline phosphatase (ALP) activity, a biomarker of differentiation. As a result, we identified that 950 nm NIR PBM solves cryodamage in human stem cells from the apical papilla, indicating its potential as an alternative to antioxidants for treatment of post-thawing trauma, and further estimated its mechanism.

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Section: Discussionmentioning

confidence: 99%

Photobiomodulation as an antioxidant substitute in post-thawing trauma of human stem cells from the apical papilla

Choi

Baik

Jeong

et al. 2021

Sci Rep

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“…Whenever cells are void of their native environment (in vitro) or in the vicinity of injured tissues (in vivo), they experience stress, manifesting itself in the form of extended bursts of mitochondrial ROS. An inescapable physical consequence of the associated increase in IWL viscosity in the predominantly hydrophilic intramitochondrial space is the decrease in the speed of rotation of the mitochondrial rotary motor (ATP synthase), 11 which must react sensitively to changes in viscosity because of its small inertia and very high speed of rotation (under normal conditions the nanomotor operates at ca. 9000 rpm).…”

Section: Biological Effect Of Viscosity Variationmentioning

confidence: 99%

Revisiting the Photon/Cell Interaction Mechanism in Low-Level Light Therapy

Sommer¹

2019

Photobiomodulation, Photomedicine, and Laser Surgery

Self Cite

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Objective: Several reports claim that the enzyme cytochrome c oxidase (CCO) is the primary absorber for redto-near-infrared (R-NIR) light in cells and causal for mitochondrial adenosine triphosphate (ATP) upregulation, and that pulsed R-NIR light has frequent therapeutic effects, which are superior to those of the continuous wave (CW) mode used in low-level light therapy (LLLT). Background data: Convincing evidence that the absorption of R-NIR photons by CCO is involved in mitochondrial ATP upregulations as well as a coherent explanation for the superiority of the pulsed irradiation mode is presently lacking in the literature. Methods: A comprehensive literature search and rigorous analysis of the data published on the idea that CCO is the primary absorber for R-NIR light, and of the claim that the effectivity of the pulsed irradiation mode can be derived from the absorption of R-NIR photons by CCO, reveal a number of severe inconsistencies. Results: A systematical analysis covering both the theory that CCO is the primary acceptor for R-NIR light and of its use to interpret differences between the biological effect of pulsed light and CW casts doubt on the general validity of the CCO-based hypothesis. Instead, we are offered a simple and conflict-free model accounting for both ATP upregulation and superiority of the pulsed mode in LLLT, which is in agreement with the results of recent laboratory experiments. Conclusions: CCO is not the primary acceptor for R-NIR light.

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“…It should be noted that some consumer devices use continuous irradiation, most notably the 670 nm LED device WARP10. 17,49…”

Section: Pulsingmentioning

confidence: 99%

Therapeutic Efficacy of Home-Use Photobiomodulation Devices: A Systematic Literature Review

Gavish

Houreld

2019

Photobiomodulation, Photomedicine, and Laser Surgery

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Objective: Perform systematic literature review on photobiomodulation (PBM) devices used at home for nonesthetic applications. Background: Home-use PBM devices have been marketed for cosmetic and therapeutic purposes. This is the first systematic literature review for nonesthetic applications. Methods: A systematic literature search was conducted for PBM devices self-applied at home at least thrice a week. Two independent reviewers screened the articles and extracted the data. Treatment dosage appropriateness was compared to the World Association for Laser Therapy (WALT) recommendations. The efficacy was evaluated according to the relevant primary end-point for the specific indication. Results: Eleven studies were suitable. Devices were applied for a range of indications, including pain, cognitive dysfunction, wound healing, diabetic macular edema, and postprocedural side effects, and were mostly based on near-infrared, pulsed light-emitting diodes with dosages within WALT recommendations. Regarding efficacy, studies reported mostly positive results. Conclusions: Home-use PBM devices appear to mediate effective, safe treatments in a variety of conditions that require frequent applications. Conclusive evaluation of their efficacy requires additional, randomized controlled studies.

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Aging Is a Sticky Business

Abstract: An understanding of the mechanism of interaction of red-to NIR light with mitochondria, cells, and tissues safeguards progress in the field of low-level light therapy (LLLT) and puts us in the position to design better therapies.

Cited by 5 publications

References 19 publications

Photobiomodulation as an antioxidant substitute in post-thawing trauma of human stem cells from the apical papilla

Photobiomodulation as an antioxidant substitute in post-thawing trauma of human stem cells from the apical papilla

Revisiting the Photon/Cell Interaction Mechanism in Low-Level Light Therapy

Therapeutic Efficacy of Home-Use Photobiomodulation Devices: A Systematic Literature Review

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