Photobiomodulation in the infrared spectrum reverses the expansion of circulating natural killer cells and brain microglial activation in Sanfilippo mice.

Sanfilippo syndrome results from inherited mutations in genes encoding lysosomal enzymes that catabolise heparan sulfate (HS), leading to early childhood-onset neurodegeneration. This study explores the therapeutic potential of photobiomodulation (PBM), which is neuroprotective and anti-inflammatory in several neurodegenerative diseases; it is also safe and PBM devices are readily available. We investigated the effects of 10-14 days transcranial PBM at 670 nm (2 or 4 J/cm2/day) or 904 nm (4 J/cm2/day) in young (3 weeks) and older (15 weeks) Sanfilippo or mucopolysaccharidosis type IIIA (MPS IIIA) mice. Although we found no PBM-induced changes in HS accumulation, astrocyte activation, CD206 (an anti-inflammatory marker) and BDNF expression in the brains of Sanfilippo mice, there was a near-normalisation of microglial activation in older MPS IIIA mice by 904 nm PBM, with decreased IBA1 expression and a return of their morphology towards a resting state. Immune cell immunophenotyping of peripheral blood with mass cytometry revealed increased pro-inflammatory signalling through pSTAT1 and p-p38 in NK and T cells in young but not older MPS IIIA mice (5 weeks of age), and expansion of NK, B and CD8+ T cells in older affected mice (17 weeks of age), highlighting the importance of innate and adaptive lymphocytes in Sanfilippo syndrome. Notably, 670 and 904 nm PBM both reversed the Sanfilippo-induced increase in pSTAT1 and p-p38 expression in multiple leukocyte populations in young mice, while 904 nm reversed the increase in NK cells in older mice. In conclusion, this is the first study to demonstrate the beneficial effects of PBM in Sanfilippo mice. The distinct reduction in microglial activation and NK cell pro-inflammatory signalling and number suggests PBM may alleviate neuroinflammation and lymphocyte activation, encouraging further investigation of PBM as a standalone, or complementary therapy in Sanfilippo syndrome.

Enhancing Osteoblast Differentiation from Adipose-Derived Stem Cells Using Hydrogels and Photobiomodulation: Overcoming In Vitro Limitations for Osteoporosis Treatment.

Osteoporosis represents a widespread and debilitating chronic bone condition that is increasingly prevalent globally. Its hallmark features include reduced bone density and heightened fragility, which significantly elevate the risk of fractures due to the decreased presence of mature osteoblasts. The limitations of current pharmaceutical therapies, often accompanied by severe side effects, have spurred researchers to seek alternative strategies. Adipose-derived stem cells (ADSCs) hold considerable promise for tissue repair, albeit they encounter obstacles such as replicative senescence in laboratory conditions. In comparison, employing ADSCs within three-dimensional (3D) environments provides an innovative solution, replicating the natural extracellular matrix environment while offering a controlled and cost-effective in vitro platform. Moreover, the utilization of photobiomodulation (PBM) has emerged as a method to enhance ADSC differentiation and proliferation potential by instigating cellular stimulation and facilitating beneficial performance modifications. This literature review critically examines the shortcomings of current osteoporosis treatments and investigates the potential synergies between 3D cell culture and PBM in augmenting ADSC differentiation towards osteogenic lineages. The primary objective of this study is to assess the efficacy of combined 3D environments and PBM in enhancing ADSC performance for osteoporosis management. This research is notably distinguished by its thorough scrutiny of the existing literature, synthesis of recent advancements, identification of future research trajectories, and utilization of databases such as PubMed, Scopus, Web of Science, and Google Scholar for this literature review. Furthermore, the exploration of biomechanical and biophysical stimuli holds promise for refining treatment strategies. The future outlook suggests that integrating PBM with ADSCs housed within 3D environments holds considerable potential for advancing bone regeneration efforts. Importantly, this review aspires to catalyse further advancements in combined therapeutic strategies for osteoporosis regeneration.

Photobiomodulation transiently increases the spontaneous firing in the superficial layer of the rat spinal dorsal horn.

The therapeutic benefits of photobiomodulation (PBM) in pain management, although well documented, are accompanied by concerns about potential risks, including pain, particularly at higher laser intensities. This study investigated the effects of laser intensity on pain perception using behavioral and electrophysiological evaluations in rats. Our results show that direct laser irradiation of 1000 mW/cm2 to the sciatic nerve transiently increases the frequency of spontaneous firing in the superficial layer without affecting the deep layer of the spinal dorsal horn, and this effect reverses to pre-irradiation levels after irradiation. Interestingly, laser irradiation at 1000 mW/cm2, which led to an increase in spontaneous firing, did not prompt escape behavior. Furthermore, a significant reduction in the time to initiate escape behavior was observed only at 9500 mW/cm2 compared to 15, 510, 1000, and 4300 mW/cm2. This suggests that 1000 mW/cm2, the laser intensity at which an increase in spontaneous firing was observed, corresponds to a stimulus that did not cause pain. It is expected that a detailed understanding of the risks and mechanisms of PBM from a neurophysiological perspective will lead to safer and more effective use of PBM.

Photobiomodulation inhibits neuronal firing in the superficial but not deep layer of a rat spinal dorsal horn.

Photobiomodulation (PBM) has attracted attention as a treatment for chronic pain. Previous studies have reported that PBM of the sciatic nerve inhibits neuronal firing in the superficial layers (lamina I-II) of the spinal dorsal horn of rats, which is evoked by mechanical stimulation that corresponds to noxious stimuli. However, the effects of PBM on the deep layers (lamina III-IV) of the spinal dorsal horn, which receive inputs from innocuous stimuli, remain poorly understood. In this study, we examined the effect of PBM of the sciatic nerve on firing in the deep layers of the spinal dorsal horn evoked by mechanical stimulation. Before and after PBM, mechanical stimulation was administered to the cutaneous receptive field using 0.6-26.0 g von Frey filaments (vFFs), and vFF-evoked firing in the deep layers of the spinal dorsal horn was recorded. The vFF-evoked firing frequencies were not altered after the PBM for any of the vFFs. The inhibition rate for 26.0 g vFF-evoked firing was approximately 13 % in the deep layers and 70 % in the superficial layers. This suggests that PBM selectively inhibits the transmission of pain information without affecting the sense of touch. PBM has the potential to alleviate pain while preserving the sense of touch.

Inflammation in obsessive-compulsive disorder: A literature review and hypothesis-based potential of transcranial photobiomodulation.

Obsessive-compulsive disorder (OCD) is a disabling neuropsychiatric disorder that affects about 2%-3% of the global population. Despite the availability of several treatments, many patients with OCD do not respond adequately, highlighting the need for new therapeutic approaches. Recent studies have associated various inflammatory processes with the pathogenesis of OCD, including alterations in peripheral immune cells, alterations in cytokine levels, and neuroinflammation. These findings suggest that inflammation could be a promising target for intervention. Transcranial photobiomodulation (t-PBM) with near-infrared light is a noninvasive neuromodulation technique that has shown potential for several neuropsychiatric disorders. However, its efficacy in OCD remains to be fully explored. This study aimed to review the literature on inflammation in OCD, detailing associations with T-cell populations, monocytes, NLRP3 inflammasome components, microglial activation, and elevated proinflammatory cytokines such as TNF-α, CRP, IL-1ß, and IL-6. We also examined the hypothesis-based potential of t-PBM in targeting these inflammatory pathways of OCD, focusing on mechanisms such as modulation of oxidative stress, regulation of immune cell function, reduction of proinflammatory cytokine levels, deactivation of neurotoxic microglia, and upregulation of BDNF gene expression. Our review suggests that t-PBM could be a promising, noninvasive intervention for OCD, with the potential to modulate underlying inflammatory processes. Future research should focus on randomized clinical trials to assess t-PBM's efficacy and optimal treatment parameters in OCD. Biomarker analyses and neuroimaging studies will be important in understanding the relationship between inflammatory modulation and OCD symptom improvement following t-PBM sessions.

Effects of slit lamp-delivered retinal laser photobiomodulation in a rat model of choroidal neovascularization.

Neovascular age-related macular degeneration, also known as exudative or wet age-related macular degeneration, is the leading cause of blindness in the developed world. Photobiomodulation has the potential to target the up-stream hypoxic and pro-inflammatory drivers of choroidal neovascularization. This study investigated whether photobiomodulation attenuates characteristic pathological features of choroidal neovascularization in a rodent model. Experimental choroidal neovascularization was induced in Brown Norway rats with laser photocoagulation. A custom-designed, slit-lamp-mounted, 670 nm laser was used to administer retinal photobiomodulation every 3 days, beginning 6 days prior to choroidal neovascularization induction and continuing until the animals were killed 14 days later. The effect of photobiomodulation on the size of choroidal neovascular membranes was determined using isolectin-B4 immunohistochemistry and spectral domain-optical coherence tomography. Vascular leakage was determined with fluorescein angiography. The effect of treatment on levels of vascular endothelial growth factor expression was quantified with enzyme-linked immunosorbent assay. Treatment with photobiomodulation was associated with choroidal neovascular membranes that were smaller, had less fluorescein leakage, and a diminished presence of inflammatory cells as compared to sham eyes. These effects were not associated with a statistically significant difference in the level of vascular endothelial growth factor when compared to sham eyes. The data shown herein indicate that photobiomodulation attenuates pathological features of choroidal neovascularization in a rodent model by mechanisms that may be independent of vascular endothelial growth factor.

Targeting Wnt/ß-catenin signaling and its interplay with TGF-ß and Notch signaling pathways for the treatment of chronic wounds.

Wound healing is a tightly regulated process that ensures tissue repair and normal function following injury. It is modulated by activation of pathways such as the transforming growth factor-beta (TGF-ß), Notch, and Wnt/ß-catenin signaling pathways. Dysregulation of this process causes poor wound healing, which leads to tissue fibrosis and ulcerative wounds. The Wnt/ß-catenin pathway is involved in all phases of wound healing, primarily in the proliferative phase for formation of granulation tissue. This review focuses on the role of the Wnt/ß-catenin signaling pathway in wound healing, and its transcriptional regulation of target genes. The crosstalk between Wnt/ß-catenin, Notch, and the TGF-ß signaling pathways, as well as the deregulation of Wnt/ß-catenin signaling in chronic wounds are also considered, with a special focus on diabetic ulcers. Lastly, we discuss current and prospective therapies for chronic wounds, with a primary focus on strategies that target the Wnt/ß-catenin signaling pathway such as photobiomodulation for healing diabetic ulcers.

Improving human sperm motility via red and near-infrared laser irradiation: in-vitro study.

Improved sperm motility is necessary for successful sperm passage through the female genital system, efficacious fertilization, and a greater probability of pregnancy. By stimulating the mitochondrial respiratory chain, low-level laser photobiomodulation has been shown to increase sperm motility and velocity. The respiratory chain in mitochondria is the primary site of action for cytochrome c oxidase because it can absorb light in the visible and infrared ranges. The present study aimed to investigate the effects of red laser 650 nm, near infrared laser (NIR) 980 nm, and combination of both on human spermatozoa motility and DNA integrity at different doses. An in-vitro controlled trial was performed in Al Zahraa university hospital laboratory using thirty fresh human semen specimens. Samples were exposed to red laser 650 nm, near infrared laser (NIR) 980 nm, and combination of both for various irradiation times. Sperm motility for the test and control aliquots was assessed as recommended in the manual of WHO-2021. Sperm chromatin integrity was evaluated using the Sperm Chromatin Structure Assay. Results revealed almost 70%, 80% and 100% increase in the total motility after 3 min of the 650-nm, 980-nm and the combined laser irradiation, respectively. Additionally, the Sperm Chromatin Dispersion assay was carried out on sperm heads utilizing human sperm DNA fragmentation, demonstrating that none of the three laser types had any discernible effects.

Antioxidant effects of LEDT in dystrophic muscle cells: involvement of PGC-1α and UCP-3 pathways.

PURPOSE: Reactive oxygen species and mitochondrial dysfunction play a crucial role in the pathophysiology of Duchenne muscular dystrophy (DMD). The light-emitting diode therapy (LEDT) showed beneficial effects on the dystrophic muscles. However, the mechanisms of this therapy influence the molecular pathways in the dystrophic muscles, particularly related to antioxidant effects, which still needs to be elucidated. The current study provides muscle cell-specific insights into the effect of LEDT, 48 h post-irradiation, on oxidative stress and mitochondrial parameters in the dystrophic primary muscle cells in culture. METHODS: Dystrophic primary muscle cells were submitted to LEDT, at multiple wavelengths (420 nm, 470 nm, 660 nm and 850 nm), 0.5 J dose, and evaluated after 48 h based on oxidative stress markers, antioxidant enzymatic system and biogenesis, and functional mitochondrial parameters. RESULTS: The mdx muscle cells treated with LEDT showed a significant reduction of H2O2 production and 4-HNE, catalase, SOD-2, and GR levels. Upregulation of UCP3 was observed with all wavelengths while upregulation of PGC-1α and a slight upregulation of electron transport chain complexes III and V was only observed following 850 nm LEDT. In addition, the mitochondrial membrane potential and mitochondrial mass mostly tended to be increased following LEDT, while parameters like O2·- production tended to be decreased. CONCLUSION: The data shown here highlight the potential of LEDT as a therapeutic agent for DMD through its antioxidant action by modulating PGC-1α and UCP3 levels.

Effects of photobiomodulation on different phases of in vitro osteogenesis.

The present study aimed to evaluate the effect of photobiomodulation therapy (PBM) on different stages of osteogenesis in vitro. For this, osteoblastic-like cells (Saos-2 cell lineage) were irradiated in two different periods: during the Proliferation phase (PP; from the second to the fourth day) and during the Differentiation phase (DP; from the seventh to the ninth day). The energy density used in the study was 1.5 J/ cm2. The following parameters were evaluated: 1) quantification of collagen type 1 (COL 1), osteopontin (OPN), and bone morphogenetic protein 2 (BMP-2); 2) quantification of alkaline phosphatase (ALP) activity; and 3) quantification of  extracellular matrix (ECM) mineralization. Non-irradiated cultures were used as controls. The data were analyzed using the Student's t-test or one-way ANOVA, considering a significance level of 5%. The results indicated that COL 1 and BMP-2 quantification was higher in Saos-2 irradiated during the DP in relation to the control group at day 10 (p < 0.05). No differences were observed for other comparisons at this time point (p > 0.05). OPN expression was greater in PP compared with the other experimental groups at day 10 (p < 0.05). Irradiation did not affect ALP activity in Saos-2 regardless of the exposure phase and the time point evaluated (p > 0.05). At day 14, ECM mineralization was higher in Saos-2 cultures irradiated during the DP in relation to the PP (p < 0.05). In conclusion, the results suggested that the effects of PBM on osteoblastic cells may be influenced by the stage of cell differentiation.

Red light mediates the exocytosis of vasodilatory vesicles from cultured endothelial cells: a cellular, and ex vivo murine model.

We have previously established that 670 nm energy induces relaxation of blood vessels via an endothelium derived S-nitrosothiol (RSNO) suggested to be embedded in vesicles. Here, we confirm that red light facilitates the exocytosis of this vasodilator from cultured endothelial cells and increases ex vivo blood vessel diameter. Ex vivo pressurized and pre-constricted facial arteries from C57Bl6/J mice relaxed 14.7% of maximum diameter when immersed in the medium removed from red-light exposed Bovine Aortic Endothelial Cells. In parallel experiments, 0.49 nM RSNO equivalent species was measured in the medium over the irradiated cells vs dark control. Electron microscopy of light exposed endothelium revealed significant increases in the size of the Multi Vesicular Body (MVB), a regulator of exosome trafficking, while RSNO accumulated in the MVBs as detected with immunogold labeling electron microscopy (1.8-fold of control). Moreover, red light enhanced the presence of F-actin related stress fibers (necessary for exocytosis), and the endothelial specific marker VE-cadherin levels suggesting an endothelial origin of the extracellular vesicles. Flow cytometry coupled with DAF staining, an indirect sensor of nitric oxide (NO), indicated significant amounts of NO within the extracellular vesicles (1.4-fold increase relative to dark control). Therefore, we further define the mechanism on the 670 nm light mediated traffic of endothelial vasodilatory vesicles and plan to leverage this insight into the delivery of red-light therapies.

Transcranial photobiomodulation for neurodevelopmental disorders: a narrative review.

BACKGROUND: Neurodevelopmental disorders (NDDs) such as autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and Down syndrome (DS) significantly impact social, communicative, and behavioral functioning. Transcranial photobiomodulation (t-PBM) with near-infrared light is a promising non-invasive neurostimulation technique for neuropsychiatric disorders, including NDDs. This narrative review aimed to examine the preclinical and clinical evidence of photobiomodulation (PBM) in treating NDDs. METHODS: A comprehensive search across six databases was conducted, using a combination of MeSH terms and title/abstract keywords: "photobiomodulation", "PBM", "neurodevelopmental disorders", "NDD", and others. Studies applying PBM to diagnosed NDD cases or animal models replicating NDDs were included. Protocols, reviews, studies published in languages other than English, and studies not evaluating clinical or cognitive outcomes were excluded. RESULTS: Nine studies were identified, including one preclinical and eight clinical studies (five on ASD, two on ADHD, and one on DS). The reviewed studies encompassed various t-PBM parameters (wavelengths: 635-905 nm) and targeted primarily frontal cortex areas. t-PBM showed efficacy in improving disruptive behavior, social communication, cognitive rigidity, sleep quality, and attention in ASD; in enhancing attention in ADHD; and in improving motor skills and verbal fluency in DS. Minimal adverse effects were reported. Proposed mechanisms involve enhanced mitochondrial function, modulated oxidative stress, and reduced neuroinflammation. CONCLUSIONS: t-PBM emerges as a promising intervention for NDDs, with potential therapeutic effects across ASD, ADHD, and DS. These findings underscore the need for further research, including larger-scale, randomized sham-controlled clinical trials with comprehensive biomarker analyses, to optimize treatment parameters and understand the underlying mechanisms associated with the effects of t-PBM.

Implementation of a light therapy team to administer photobiomodulation therapy: A standardized protocol to prevent and treat oral mucositis in the pediatric hematopoietic stem cell transplant population.

BACKGROUND: Oral mucositis (OM) is a painful and common complication of hematopoietic stem cell transplant (HSCT). The Children's Oncology Group recently published guidelines recommending photobiomodulation (PBM) for preventing and treating OM in pediatric HSCT patients. However, this is a rarely used intervention in pediatric hospitals. PROCEDURE: Patients undergoing allogeneic HSCT, or autologous HSCT for a neuroblastoma diagnosis, had PBM administered from the first day of conditioning to transplant Day +20. We successfully developed a standardized treatment protocol and workflow to ensure consistent and uniform delivery of PBM. In addition, clinical patient data were compared before and after PBM implementation. RESULTS: The administration of PBM at our center was feasible, but required dedicated staff. A registered nurse (RN) was determined to be the best fit to deliver PBM. Sixty-two patients received PBM from October 2022 to September 2023; patients from 2021 before PBM implementation were used for comparison. Patients receiving PBM were more likely (p = .03) to engage in teeth brushing (56/62 = 90%) compared to baseline (61/81 = 75%). Mean days of OM decreased from 11.3 to 9 days; patients who received PBM were less likely (p < .001) to be discharged on total parental nutrition (TPN) (11/62 = 18%) compared to baseline (50/82 = 61%). OM-related supportive care costs (TPN and patient-controlled anesthesia [PCA]) were lower (p = .02) for those who received PBM (median cost = $31,229.87 vs. $37,370.66). CONCLUSION: PBM, as the standard of care in the pediatric HSCT population, is safe, feasible, and well-tolerated. At our center, a dedicated RN was critical to providing standardized treatment and ensuring sustainability.

Photobiomodulation combination therapy as a new insight in neurological disorders: a comprehensive systematic review.

Preclinical and clinical studies have indicated that combining photobiomodulation (PBM) therapy with other therapeutic approaches may influence the treatment process in a variety of disorders. The purpose of this systematic review was to determine whether PBM-combined therapy provides additional benefits over monotherapies in neurologic and neuropsychiatric disorders. In addition, the review describes the most commonly used methods and PBM parameters in these conjunctional approaches.To accomplish this, a systematic search was conducted in Google Scholar, PubMed, and Scopus databases through January 2024. 95 potentially eligible articles on PBM-combined treatment strategies for neurological and neuropsychological disorders were identified, including 29 preclinical studies and 66 clinical trials.According to the findings, seven major categories of studies were identified based on disease type: neuropsychiatric diseases, neurodegenerative diseases, ischemia, nerve injury, pain, paresis, and neuropathy. These studies looked at the effects of laser therapy in combination with other therapies like pharmacotherapies, physical therapies, exercises, stem cells, and experimental materials on neurological disorders in both animal models and humans. The findings suggested that most combination therapies could produce synergistic effects, leading to better outcomes for treating neurologic and psychiatric disorders and relieving symptoms.These findings indicate that the combination of PBM may be a useful adjunct to conventional and experimental treatments for a variety of neurological and psychological disorders.

Improvements in clinical signs and symptoms of Parkinson's disease using photobiomodulation: a five-year follow-up.

BACKGROUND: Parkinson's disease is a progressive neurodegenerative disease characterized by clinical motor signs and non-motor symptoms that severely impact quality of life. There is an urgent need for therapies that might slow, halt or even reverse the progression of existing symptoms or delay the onset of new symptoms. Photobiomodulation is a therapy that has shown potential to alleviate some symptoms of Parkinson's disease in animal studies and in small clinical trials. OBJECTIVE: To assess long-term effectiveness of photobiomodulation therapy in a cohort of Parkinson's disease individuals after five years of continuing therapy. METHODS: Eight participants of the initial 12 in a previously published study agreed to be reassessed after five years. Seven of these participants had continued home-based, self-applied photobiomodulation therapy three times per week for five years. One participant had discontinued treatment after one year. Participants were assessed for a range of clinical motor signs, including MDS-UPDRS-III, measures of mobility and balance. Cognition was assessed objectively, and quality of life and sleep quality were assessed using self-reported questionnaires. A Wilcoxon Signed Ranks test was used to evaluate change in outcome measures between baseline (before treatment) and after five years, with the alpha value set to 0.05. RESULTS: Of the seven participants who had continued photobiomodulation therapy, one had a preliminary diagnosis of multisystem atrophy and was excluded from the group analysis. For the remaining six participants, there was a significant improvement in walk speed, stride length, timed up-and-go tests, tests of dynamic balance, and cognition compared to baseline and nonsignificant improvements in all other measures, apart from MDS-UPDRS-III, which was unchanged and one measure of static balance (single leg stance, standing on the unaffected leg with eyes open) which declined. Five of six participants either improved or showed no decline in MDS-UPDRS-III score and most participants showed improvement or no decline in all other outcome measures. No adverse effects of the photobiomodulation therapy were reported. CONCLUSIONS: This study provides a signal that photobiomodulation therapy might safely reduce important clinical motor signs and non-motor symptoms in some Parkinson's disease patients, with improvements maintained over several years. Home-based photobiomodulation therapy has the potential to complement standard therapies to manage symptoms and potentially delay Parkinson's symptom progression. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, registration number ACTRN12618000038291p, registered on 12/01/2018.

Photobiomodulation CME part II: Clinical applications in dermatology.

Photobiomodulation (PBM) is an emerging treatment modality in dermatology with increasing office and home-based use. PBM is the use of various light sources in the red light (620-700 nm) and near-infrared (700-1440 nm) spectrum as a form of light therapy. PBM is often administered through low-level lasers or light-emitting diodes. Studies show that PBM can be used effectively to treat conditions secondary to cancer therapies, alopecia, ulcers, herpes simplex virus, acne, skin rejuvenation, wounds, and scars. PBM offers patients many benefits compared to other treatments. It is noninvasive, cost-effective, convenient for patients, and offers a favorable safety profile. PBM can be used as an alternative or adjuvant to other treatment modalities including pharmacotherapy. It is important for dermatologists to gain a better clinical understanding of PBM for in-office administration and to counsel patients on proper application for home-use devices to best manage safety and expectations as this technology develops. PBM wavelengths can induce varied biological effects in diverse skin types, races, and ethnicities; therefore, it is also important for dermatologists to properly counsel their skin of color patients who undergo PBM treatments. Future clinical trials are necessary to produce standardized recommendations across conditions and skin types.

Photobiomodulation CME Part I: Overview and Mechanism of Action.

Photobiomodulation (PBM), previously known as low-level laser light therapy, represents a non-invasive form of phototherapy that utilizes wavelengths in the red light (RL, 620-700 nm) portion of the visible light (VL, 400-700 nm) spectrum and the near-infrared (NIR, 700-1440 nm) spectrum. PBM is a promising and increasingly used therapy for the treatment of various dermatologic and non-dermatologic conditions. Photons from RL and NIR are absorbed by endogenous photoreceptors including mitochondrial cytochrome C oxidase (COX). Activation of COX leads to the following changes: modulation of mitochondrial adenosine triphosphate (ATP), generation of reactive oxygen species (ROS), and alterations in intracellular calcium levels. The associated modulation of ATP, ROS and calcium levels promotes the activation of various signaling pathways (e.g., insulin-like growth factors, phosphoinositide 3-kinase pathways), which contribute to downstream effects on cellular proliferation, migration and differentiation. Effective PBM therapy is dependent on treatment parameters (e.g., fluence, treatment duration and output power). PBM is generally well-tolerated and safe with erythema being the most common and self-limiting adverse cutaneous effect.

Effect of photobiomodulation with different wavelengths on periodontal repair in non-hyperglycemic and hyperglycemic rats.

BACKGROUND: Hyperglycemic conditions is associated with more severe periodontitis and poorer outcomes after nonsurgical periodontal treatment (NPT). Then, these patients are candidates for adjunctive therapy associated with NPT. This study evaluates the effect of photobiomodulation (PBMT) at different wavelengths on periodontal repair in non-hyperglycemic/hyperglycemic animals. MATERIALS AND METHODS: Sixty-four rats were submitted to induction of periodontitis by ligatures. Hyperglycemia was induced in half of these animals, whereas the other half remained non-hyperglycemic. The animals were subdivided into 4 groups according to the PBMT protocol applied at the time of ligature removal (n = 8): CTR: Without PBMT; IRL: PBMT with infrared laser (808 nm); RL: PBMT with red laser (660 nm); and RL-IRL: PBMT with red (660 nm) and infrared laser (808 nm). After a period of 7 days, the animals were euthanized. The parameters assessed by microtomography were the bone volume relative to total tissue volume (BV/TV%), distance from the cemento-enamel junction to the top of the bone crest (CEJ-CB), trabecular thickness, space between trabeculae, and number of trabeculae. Additionally, the percentage of inflammatory cells, blood vessels, and connective tissue matrix were assessed by histomorphometric analysis. RESULTS: PBMT reduced bone loss and increased trabecular density in hyperglycemic animals (p < .05), with RL being more effective in reducing linear bone loss (CEJ-CB), whereas RL-IRL was more effective in maintaining BV/TV%. PBMT reduced blood vessels and increased the connective tissue component in hyperglycemic animals (p < .05). RL-IRL reduced inflammatory cells regardless of the systemic condition of the animal (p < .05). CONCLUSION: PBMT (RL, RL-IRL) improves the repair of periodontal tissues in hyperglycemic animals.

Medication-related osteonecrosis of the jaw: evolving research for multimodality medical management.

PURPOSE: Medication-related osteonecrosis of the jaw (MRONJ) is a debilitating side effect of antiresorptive and antiangiogenic agents that can lead to progressive bone destruction in the maxillofacial region. Dental surgery, including tooth extractions, commonly trigger the onset of MRONJ. While guidelines suggest avoiding extraction when possible, complete avoidance is not always feasible, as necrosis can develop from dental and periodontal disease without dental procedures. The goal of this article is to provide an update review of current preventive and therapeutic approaches for MRONJ. METHODS: A comprehensive electronic search was conducted on PubMed/MEDLINE, Embase, and Scopus databases. All English articles encompassing randomized controlled trials, systematic reviews, observational studies, and case studies were reviewed. The current medical treatments and adjuvant therapies for managing MRONJ patients were critically assessed and summarized. RESULTS: Pentoxifylline and alpha tocopherol (PENT-E), teriparatide, photobiomodulation (PBM), photodynamic therapy (PDT), and the use of growth factors have shown to enhance healing in MRONJ patients. Implementing these methods alone or in conjunction with surgical treatment has been linked to reduced discomfort and improved wound healing and increased new bone formation. DISCUSSION: While several adjuvant treatment modalities exhibit promising results in facilitating the healing process, current clinical practice guidelines predominantly recommend antibiotic therapy as a non-surgical approach, primarily addressing secondary infections in necrotic areas. However, this mainly addresses the potential infectious complication of MRONJ. Medical approaches including PENT-E, teriparatide, PBM, and PDT can result in successful management and should be considered prior to taking a surgical approach. Combined medical management for both preventing and managing MRONJ holds potential for achieving optimal clinical outcomes and avoiding surgical intervention, requiring further validation through larger studies and controlled trials.

Oral mucositis management with photobiomodulation, Bidens pilosa L. (Asteraceae) and Curcuma longa L. (Zingiberaceae), the FITOPROT herbal medicine, and its influence on inflammatory cytokine levels: a randomized clinical trial.

PURPOSE: This randomized clinical trial aimed to compare the effects of a mucoadhesive formula, containing curcuminoids from Curcuma longa L. and glycerinated extract of Bidens pilosa L. (FITOPROT), associated with photobiomodulation (PBM), and of PBM exclusively, on the incidence of oral mucositis (OM)-induced by radiotherapy (RT) in the head and neck region, and the salivary expression of inflammatory cytokines, in patients with head neck cancer. METHODS: Patients were randomly assigned into two intervention groups-FITOPROT + PBM (n = 25) or PBM (n = 27). PBM protocol comprised a wavelength of 660 nm, 25 mW, 0.25 J/point, and daily irradiation from the first until the last day of RT. FITOPROT was gargled twice a day. All patients underwent a preventive oral care program throughout the study. OM degree, salivary concentration of nitrite, and inflammatory (IL-1, TNFα, IL-6, IL-8, and IL-12p70), and anti-inflammatory (IL-10) cytokines were assessed at baseline, and at the 7th, 14th, 21st, and 30th RT sessions. RESULTS: There were no differences in the OM degree between groups, but the RT dose significantly affected the OM. The RT significantly affected the salivary nitrite, TNFα, IL-1ß, and IL-10 concentrations. CONCLUSION: FITOPROT associated with PBM showed limited effects on preventing the incidence of severe OM compared to PBM alone. However, FITOPROT + PBM may be associated with nitrite and cytokine balance, which may contribute to the occurrence of fewer cases of severe OM. TRIAL REGISTRATION: Brazilian Clinical Trials database (ReBEC; RBR-9vddmr), registered UTN code: U1111-1193-2066, registered in August 8th, 2017.