Good, better, best? The effects of polarization on photobiomodulation therapy

Abstract

Photobiomodulation therapy (PBMT) is a widely adopted form of phototherapy used to treat many chronic conditions that effect the population at large. The exact physiological mechanisms of PBMT remain unsolved; however, the prevailing theory centres on changes in mitochondrial function. There are many irradiation parameters to consider when investigating PBMT, one of which is the state of polarization. There is some evidence to show that polarization of red and nearinfrared light may promote different and/or increased biological activity when compared to otherwise identical non-polarized light. These enhanced cellular effects may also be present when the polarized light is applied linear to the tissue direction. Herein, we synthesize the current experimental and clinical evidence pertaining to polarized photobiomodulation therapy; ultimately, to better inform future research into this area of phototherapy.

Photobiomodulation reduces neuropathic pain after spinal cord injury by downregulating CXCL10 expression

“…12 The absorption of red/near-infrared light enhances mitochondrial ATP production, cell signaling and growth factor synthesis, and attenuates oxidative stress and inflammation responses. 13,14 PBM is used clinically and provides therapeutical effects on diseases including Alzheimer's disease 15 and wound care. 16 Although no clinical studies have reported the therapeutic effects of PBM for the treatment of NP after SCI, effective relief for NP in rats after SCI has been reported in several preclinical studies.…”

“…Photobiomodulation (PBM) is a treatment performed using very low energy light, which is sufficient to produce stimulation, but does not damage the target system 12 . The absorption of red/near‐infrared light enhances mitochondrial ATP production, cell signaling and growth factor synthesis, and attenuates oxidative stress and inflammation responses 13,14 . PBM is used clinically and provides therapeutical effects on diseases including Alzheimer's disease 15 and wound care 16 .…”

Patellar Tendinopathy: Critical Analysis Review of Current Nonoperative Treatments

“…Low-level laser therapy (LLLT) is an emerging treatment modality that consists of local application of a nonionizing light source to stimulate photobiomodulation (PBM) in the target tissue 82,83 . While understanding of the exact physiological mechanism remains limited, the general principle is that PBM can lead to a reduction of inflammation and promotion of tissue regeneration 82,83 . Current theories suggest an interplay of red and near-infrared light with cytochrome c oxidase within the mitochondria to enhance adenosine triphosphate production 84 .…”

Regeneration of taste through sonic hedgehog upregulation by photobiomodulation

“…Photobiomodulation (PBM) therapy uses light at visible, infrared, and near‐infrared wavelengths to modulate biological reactions that are not thermal or cytotoxic through photochemical photophysical events, leading to physiological changes [12]. Even though the underlying action mechanism of PBM has not been entirely explained yet, the widely accepted theory is that light stimulates the enzyme cytochrome C oxidase (CcOX) in the mitochondrial respiratory chain by facilitating electron transport [13]. This stimulation increases adenosine triphosphate (ATP) [14] and activates the cell signaling pathways.…”