Homeostatic photobiomodulation

The use of LED therapy to treat synovial joints disorders: scoping review

The aim of this scoping review was to assess the extent of the literature on the use of LED therapy to treat synovial joint disorders. The JBI methodology for scoping reviews was followed. The databases used were PUBMED, EMBASE, Scopus, Web of Science, LILACS, PEDro, Cochrane Database, Google Scholar and ProQuest. To be included, studies should have used LED as therapy, and include at least one measure related to the structures of any synovial joint. The search strategy included all keywords and indexed terms identified in the articles. Studies in any language and in any year, whether published or not, were included. The analysis of the studies was carried out by two independent reviewers. Data were extracted from articles using a data extraction tool developed by the reviewers. After carrying out the definitive search and selection, 47 publications were included: 15 clinical trials, 8 clinical protocols, 12 animal studies, 4 in vitro studies and 8 reviews on the topic. Studies have shown great variability from the device and number of diodes used, to the parameters and dosimetry chosen. Some positive effects were observed: on cell proliferation (in vitro); on anti-inflammatory biomarkers (murine models) and on pain scale (clinical trials - TMD). Although, the cause of non-significant results in clinical trials was rarely discussed: depth of penetration, dosimetry, follow-up time? Thus, future studies should focus on answering more elementary aspects about the LED effect when used alone in different synovial joints.

Photobiomodulation as a promising new tool in the management of psychological disorders: A systematic review

Photobiomodulation is a brain modulation technique that has become a promising treatment for multiple pathologies. This systematic review collects studies up to 2019 about the beneficial effects of photobiomodulation as a therapy for treating psychological disorders and a tool for modulating cognitive processes. This technique is mostly used for the treatment of depression and stress, as well as to study its effects on psychological variables in healthy subjects. Despite the lack of parameters used, photobiomodulation seems to achieve enough brain penetration to produce beneficial effects in healthy subjects and patients with multiple pathologies. The best parameters are the wavelengths of 810 nm for the treatment of depression and 1064 nm for cognitive enhancement, along with a scalp irradiance of 250 mW/cm² and a scalp yield of 60 J/cm². It weekly application on the bilateral prefrontal area and the default mode network seems to be ideal for the maintenance of the effects. Photobiomodulation could be used as an effective and safe therapy for the treatment of multiple psychological pathologies.

Neuroprotective Effects Against POCD by Photobiomodulation: Evidence from Assembly/Disassembly of the Cytoskeleton

Postoperative cognitive dysfunction (POCD) is a decline in memory following anaesthesia and surgery in elderly patients. While often reversible, it consumes medical resources, compromises patient well-being, and possibly accelerates progression into Alzheimer's disease. Anesthetics have been implicated in POCD, as has neuroinflammation, as indicated by cytokine inflammatory markers. Photobiomodulation (PBM) is an effective treatment for a number of conditions, including inflammation. PBM also has a direct effect on microtubule disassembly in neurons with the formation of small, reversible varicosities, which cause neural blockade and alleviation of pain symptoms. This mimics endogenously formed varicosities that are neuroprotective against damage, toxins, and the formation of larger, destructive varicosities and focal swellings. It is proposed that PBM may be effective as a preconditioning treatment against POCD; similar to the PBM treatment, protective and abscopal effects that have been demonstrated in experimental models of macular degeneration, neurological, and cardiac conditions.

Shifting wavelengths of ultraweak photon emissions from dying melanoma cells: their chemical enhancement and blocking are predicted by Cosic's theory of resonant recognition model for macromolecules

During the first 24 h after removal from incubation, melanoma cells in culture displayed reliable increases in emissions of photons of specific wavelengths during discrete portions of this interval. Applications of specific filters revealed marked and protracted increases in infrared (950 nm) photons about 7 h after removal followed 3 h later by marked and protracted increases in near ultraviolet (370 nm) photon emissions. Specific wavelengths within the visible (400 to 800 nm) peaked 12 to 24 h later. Specific activators or inhibitors for specific wavelengths based upon Cosic's resonant recognition model elicited either enhancement or diminishment of photons at the specific wavelength as predicted. Inhibitors or activators predicted for other wavelengths, even within 10 nm, were less or not effective. There is now evidence for quantitative coupling between the wavelength of photon emissions and intrinsic cellular chemistry. The results are consistent with initial activation of signaling molecules associated with infrared followed about 3 h later by growth and protein-structural factors associated with ultraviolet. The greater-than-expected photon counts compared with raw measures through the various filters, which also function as reflective material to other photons, suggest that photons of different wavelengths might be self-stimulatory and could play a significant role in cell-to-cell communication.