The positive effects of photobiomodulation (PBM) on a variety of conditions or illnesses are often reported. Most of these studies focus on local effects: tissue that is directly exposed to red or near-infrared (NIR) light benefits. Our work takes the PBM effect a step further: a double-blind, placebo-controlled clinical study on a group (n=56) of generally healthy people shows significant (p<0.05) positive effects on health and well-being. These systemic (i.e. whole body) effects resulted from only partial exposure of their body (participants were exposed to NIR light with their face and neck only). Different doses were tested to find an optimum in terms of both effectiveness and energy usage, and the study was done in both summer and winter to verify the effect of season. In a world where most people are deprived of natural NIR light, our study shows the importance of NIR light integration in the indoor environment to enhance the health and well-being of people.

This study proposes a treatment to improve post-trauma corneal wound healing through application of short-lived bursts of reactive oxygen species obtained via ionization of interstitial water by an ultrafast laser-induced low-density plasma. Laser irradiation has been restricted to intensities below the optical breakdown threshold and applied onto interleukin-1β (IL-1β) in aqueous solution, and rabbit corneas in vivo with epithelium removed to simulate external trauma. Quantitative ELISA assays have shown lowered binding affinity of the laser-treated IL-1β to receptor IL1-R1 in aqueous solutions. Laser application on epithelium removed in-vivo rabbit corneas resulted in a preservation of stromal keratocytes and accelerated healing.

The gut microbiome has been increasingly recognised as crucial to health and has been shown to be disrupted in such diverse diseases and conditions as cardiovascular disease, renal disease, liver disease, lung infections, osteoarthritis. In addition, the microbiome-gut-brain axis has been shown to be a vital link in the neurological and neurodegenerative disorders of Alzheimer’s disease, Parkinson’s disease, autism spectrum disorder and depression. We have previously demonstrated the effect that PBM can have on the microbiome of healthy mice. In this presentation, results from a number of case studies from human trials will be presented, suggesting the potential of PBM to influence the microbiome in a positive manner. These changes correspond to improvements in a number of measures of human health in cancer treatment, Parkinson’s disease and metabolic syndrome. The interaction between light and the microbiome will be explored.

BACKGROUND: Fibromyalgia (FM) is a chronic musculoskeletal pain condition characterized by sensory hypersensitivity, widespread pain and fatigue. AIMS: To evaluate the effects of NovoTHOR® whole-body PBM on fibromyalgia.   METHOD: Forty-Two patients in a triple-blind, placebo-controlled trial were randomized to receive active or placebo NovoTHOR whole-body PBM, three times a week for four weeks.   RESULTS: There were statistically significant differences in pain and quality of life in favour of the active treatment group at the end of 4-weeks. 
CONCLUSION: NovoTHOR whole-body PBM significantly reduces pain and improves quality of life in patients with fibromyalgia.

Anaerobic exercise can gradually increase muscle mass over time as a result of adaptive responses of muscle cells to ensure metabolic homeostasis in the tissue. We found that hypoxia, which occurs during prolonged anaerobic exercise, significantly impeded myotube differentiation from myoblasts. The impediment could be prevented significantly by photobiomodulation (PBM). PBM can mitigate exercise-induced impairment of mitochondrial functions and significantly improve muscle function and exercise performance if appliable adequately. The observation provides valuable guidance with respect to the timing of PBM and its potential effects on muscle strengths in concert with anaerobic exercise.

Near-infrared photobiomodulation has been reported to have therapeutic effects in several murine Alzheimer’s disease models. As a translational institution we sought to confirm and elaborate on these findings in a blind experiment study following GLP principles. 5xFAD mice were subjected to 810 nm transcutaneous LED photobiomodulation from one to six months of age with 0 (sham), 6 or 600 mW/cm2 power density. The effects - including dependence on light power values - were investigated with a battery of memory tests (novel object recognition, Y-maze and Morris water maze) and immunohistochemical and biochemical analyses (including ABeta plaque burden, neuronal count and inflammatory markers).

Previous meta-analyses of photobiomodulation (PBM) parameters have reported correlations between effect size and emitter parameters, but the trends are not robust enough to prospectively predict doses that will yield a significant effect. A meta-analysis of PBM dosing protocols on peripheral nerves with 800 – 840 nm wavelength light was performed using Monte Carlo photon propagation models to elucidate clearer trends between dose and effect. We then tested various doses of PBM applied directly at exposed hindlimb nerve in a rodent pain model. A single application of PBM at the nerve reduced pain associated with heat-sensitive fibers for approximately 7 days.

The long-term photobiomodulation of 810 nm LED light on the IMR-32 human neuroblastoma cell line was investigated. Daily light treatments of 1.26 J/cm2 and 1.755 J/cm2 both increase resistance to doxorubicin, sodium azide, and FCCP toxicity. However, 1.26 J/cm2 increases the mitochondrial DNA copy number, alters cell cycle-related pathways’ RNA expression, and promotes cell division. Operating differently, 1.755 J/cm2 decreases the mitochondrial DNA copy number and activates the oxidative phosphorylation pathway at the RNA, protein, and functional levels. The 810 nm light treatment shows two different long-term dose-dependent effects on cellular and mitochondrial activities.

This conference presentation was prepared for the Mechanisms of Photobiomodulation Therapy XVII conference at SPIE BiOS, SPIE Photonics West 2023.

Several therapeutic effects of photobiomodultion (PBM) on variable mucosal lesions of the upper aerodigestive tract has been reported. However, the biomodulatory effect of PBM are rarely reported on tracheostomy and tracheal fenestration, which has been increased with the spread of coronavirus disease (COVID-19). In this study, we developed a translaryngeal PBM therapy by using a basket-integrated diffusing applicator (BIDA) to ameliorate the wound healing of fenestrated tracheostoma after surgery. Tracheostomy was performed by using an electrocautery unit (Bovie) to develop an in vivo porcine model of fenestrated tracheostoma with impaired wounds. A 635 nm laser light (200 mW/cm² for 3 min, 36 J/cm²) was applied to the wounds by using BIDA once daily for five days. BIDA was inserted in tracheostomy tube and emitted homogeneous circumferential light into the fenestrated wound without thermal damage. Control highly induced fibrotic expressions of alpha-smooth muscle actin and type-1 collagen with acute inflammation. In contrast, PBM reduced the expressions up to less than 82% of control. Histological scores presented that PBM significantly decreased acute inflammation and overgranulation to two-thirds of control with a small portion of abscess. In addition, a substantial difference in the lumen area was observed between the control and PBM due to the thickened wall. The current study demonstrated that the proposed PBM therapy could ameliorate the impaired wound healing of fenestrated tracheostoma as a result of modulated inflammation and fibrotic responses. Therefore, the translaryngeal PBM with BIDA can be an effective adjuvant therapy for managing the fenestrated wound after tracheostomy.

In response to the COVID-19 pandemic, we developed an innovative antimicrobial pulsed blue light technology and demonstrated that it is antiviral against HCoV-OC43 and HCoV-229E—two surrogates of SARS-CoV-2. In further studies, we developed an antiviral light panel with multiple colors—including white— using Pulsed Blue light at 450 nm that could replace commercial light fixtures. We demonstrated a 39.5% decline in viral RNA after 10hr (p <.05). This study indicates that it is possible to develop and deploy a commercial cost-effective light fixture as an environmentally safe decontaminant that can inactivate viruses and other microorganisms.

Transcranial infrared light stimulation (TILS) has been shown to improve the performance of cognitive tests in adults with subjective memory complaints. Here we study whether long-term TILS benefits the cognitive functions of the elders. Through cognitive tests including card sorting test and delayed match-to-sample test, and functional near-infrared spectroscopy, we compared the cognitive tests performance and hemodynamics at the prefrontal cortex of healthy elders before and after two-to-four weeks of daily 10-mins TILS sessions. Results showed decreased hemodynamic responses after TILS, and greater cognitive enhancements in subjects receiving longer TILS. This may be explained by elevated efficiency of oxygen metabolism after TILS.

Recently, we developed an antimicrobial light panel with multiple colors—including white—that could commercially replace light fixtures in farms and other environments that harbor deadly microorganisms. The panel emits blue 450 nm light pulsed at 33 KHz, with 6.85 W average power and 11 mW/cm2 mean irradiance. We demonstrated optimum 100% inactivation of Salmonella enterica serovar Heidelberg following 3hr of illumination with 450 nm wavelength. This finding indicates that it is possible to develop and deploy a safe commercial cost-effective light fixture that can inactivate Salmonella and decontaminate food products.