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Results for “photobiomodulation therapy”

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PubMed2026

Systematic Review on the Effectiveness of Photobiomodulation Therapy on Enhancing Musculoskeletal Rehabilitation Outcomes after Total Knee and Hip Arthroplasty.

BACKGROUND: Total knee and hip arthroplasty (TKA/THA) effectively alleviate chronic pain and improve joint function and quality of life. However, postoperative recovery is often hindered by pain, edema, restricted range of motion (ROM), and muscle weakness, necessitating structured physical rehabilitation. Photobiomodulation Therapy (PBMT) has been proposed as an adjunct modality to enhance rehabilitation outcomes. This systematic review evaluates the efficacy of PBMT in reducing postoperative pain and edema as well as improving ROM and functional performance compared with placebo or standard physical therapy in post-arthroplasty patients. METHODS: A systematic search of PubMed, ProQuest, ScienceDirect, and Google Scholar was conducted from inception to May 31, 2025. Only prospective controlled trials assessing PBMT effects on postoperative pain, swelling, ROM, or functional performance following TKA or THA were included. Case reports, uncontrolled studies, and trials focusing on unrelated outcomes were excluded. Article selection involved title, abstract, and full-text screening, with additional studies identified through reference lists. The review is registered in PROSPERO (CRD420251123169). RESULTS: Four randomized controlled trials (RCTs; n = 133 participants) met the inclusion criteria, three studies focused on TKA, and one study examined THA. PBMT significantly improved postoperative pain and edema reduction in three trials, while two studies demonstrated enhanced ROM and functional outcomes compared with control or placebo interventions. PEDro scores ranged from 8 to 10, indicating moderate-to-high methodological quality. CONCLUSIONS: PBMT shows promising short-term benefits in reducing postoperative pain and swelling and improving functional performance after knee or hip arthroplasty. However, due to heterogeneity in treatment parameters and limited high-quality trials, conclusive evidence remains insufficient. Future large-scale RCTs with standardized PBMT parameters and extended follow-up are warranted to confirm its clinical efficacy.

Humans↗

PubMed2026

Effects of Photobiomodulation Therapy in Lateral Luxation of Anterior Permanent Teeth: A Randomized, Double-Blind Clinical Trial.

BACKGROUND: Among the traumatic dental injuries (TDIs), lateral luxation may present poor prognosis due to frequent root resorption and consequent tooth loss. Photobiomodulation therapy (PBMT) modulates cellular activities (proliferation, differentiation, growth factor secretion) and may improve outcomes. OBJECTIVE: This randomized, double-blind, placebo-controlled trial evaluated PBMT (660 vs. 808 nm) for post-operative pain and pulp sensitivity recovery in lateral luxation of permanent anterior teeth. METHODS: Initially, 41 patients were included, with a total of 63 teeth traumatized by lateral luxation and were allocated to G1 (n = 21): Splinting + sham PBM (placebo), G2 (n = 21): Splinting + 808 nm infrared PBM and G3 (n = 21): Splinting + 660 nm red PBM. Four weekly sessions (3 J/point, 3 points) were administered. Pain (by numeric rating scale) and pulp sensitivity (by cold test) were assessed weekly. Pain was analyzed using the Kruskal-Wallis test, followed by multiple comparisons using Dunn's method with Bonferroni correction, and pulp sensitivity by a logistic regression model (p < 0.05). RESULTS: Three participants (total of 5 teeth) were excluded due to loss to follow-up. Fifty-eight teeth were analyzed (G1 = 21, G2 = 17, G3 = 20). Pain: All groups showed a significant reduction in pain over time (p < 0.001). Both G2 and G3 demonstrated a significantly greater reduction in pain compared to G1 (p < 0.001 and p = 0.026, respectively). No significant difference in pain reduction was observed between G2 and G3. Pulp sensitivity: G2 showed a significant improvement over time (p < 0.001), despite starting from a more unfavorable baseline. In contrast, no significant change in pulp sensitivity was observed for G1 or G3 between the initial and final assessments. CONCLUSION: Within the limitations of this clinical study, all intervention groups were effective in reducing pain in lateral luxation of permanent anterior teeth, with superior results for laser groups compared to the placebo. However, only the 808 nm laser irradiation protocol demonstrated a significant improvement in pulp sensitivity, suggesting it may offer a more complete therapeutic response.

Humans↗

PubMed2004

Mitochondrial signal transduction in accelerated wound and retinal healing by near-infrared light therapy.

Photobiomodulation by light in the red to near infrared range (630-1000 nm) using low energy lasers or light-emitting diode (LED) arrays has been shown to accelerate wound healing, improve recovery from ischemic injury in the heart and attenuate degeneration in the injured optic nerve. Recent evidence indicates that the therapeutic effects of red to near infrared light result, in part, from intracellular signaling mechanisms triggered by the interaction of NIR light with the mitochondrial photoacceptor molecule cytochrome c oxidase. We have demonstrated that NIR-LED photo-irradiation increases the production of cytochrome oxidase in cultured primary neurons and reverses the reduction of cytochrome oxidase activity produced by metabolic inhibitors. We have also shown that NIR-LED treatment prevents the development of oral mucositis in pediatric bone marrow transplant patients. Photobiomodulation improves wound healing in genetically diabetic mice by upregulating genes important in the promotion of wound healing. More recent studies have provided evidence for the therapeutic benefit of NIR-LED treatment in the survival and functional recovery of the retina and optic nerve in vivo after acute injury by the mitochondrial toxin, formic acid generated in the course of methanol intoxication. Gene discovery studies conducted using microarray technology documented a significant upregulation of gene expression in pathways involved in mitochondrial energy production and antioxidant cellular protection. These findings provide a link between the actions of red to near infrared light on mitochondrial oxidative metabolism in vitro and cell injury in vivo. Based on these findings and the strong evidence that mitochondrial dysfunction is involved in the pathogenesis of numerous diseases processes, we propose that NIR-LED photobiomodulation represents an innovative and non-invasive therapeutic approach for the treatment of tissue injury and disease processes in which mitochondrial dysfunction is postulated to play a role including diabetic retinopathy, age-related macular degeneration, Leber's hereditary optic neuropathy and Parkinson's disease.

Journal Article↗

PubMed2005

Exact action spectra for cellular responses relevant to phototherapy.

OBJECTIVE: The aim of the present work is to analyze available action spectra for various biological responses of HeLa cells irradiated with monochromatic light of 580-860 nm. BACKGROUND DATA: Phototherapy (low-level laser therapy or photobiomodulation) is characterized by its ability to induce photobiological processes in cells. Exact action spectra are needed for determination of photoacceptors as well as for further investigations into cellular mechanisms of phototherapy. METHODS: Seven action spectra for the stimulation of DNA and RNA synthesis rate and cell adhesion to glass matrix are analyzed by curve fitting, followed by deconvolusion with Lorentzian fitting. Exact parameters of peak positions and bandwidths are presented. RESULTS: The peak positions are between 613.5 and 623.5 nm (in one spectrum, at 606 nm), in the red maximum. The far-red maximum has exact peak positions between 667.5 and 683.7 nm in different spectra. Two near infrared maxima have peak positions in the range 750.7-772.3 nm and 812.5-846.0 nm, respectively. CONCLUSIONS: In the wavelength range important for phototherapy (600-860 nm), there are four "active" regions, but peak positions are not exactly the same for all spectra.

Cell Adhesion↗

PubMed2026

Efficacy of high-intensity laser therapy versus ultrasound therapy in patients with knee osteoarthritis: a randomized controlled trial.

PURPOSE: High-intensity laser therapy (HILT) and ultrasound (US) are widely used for knee osteoarthritis (KOA), but comparative efficacy data remain scarce. This study compared HILT and US as exercise adjuncts in patients with KOA. METHODS: In this single-center, assessor-blinded RCT, 66 adults with KOA were randomized 1:1 to HILT or US twice weekly for 6 weeks as exercise adjuncts. The primary outcome was WOMAC total score change from baseline to 12 weeks post-treatment (minimum important change [MIC] = 10 points, applied as an approximation). Secondary outcomes included VAS, OKS, KOOS, and EQ-5D-5L. RESULTS: In ITT analysis (N = 66), the HILT group achieved a mean WOMAC reduction of 40.0 vs 8.2 points (adjusted between-group difference: -27.7 points, 95% CI: - 39.0 to - 16.5; p < 0.001, partial η2 = 0.277). At 12 weeks post-treatment, greater improvements across all secondary outcomes were observed in exploratory analyses (p ≤ 0.012). Furthermore, HILT maintained therapeutic effects up to 12 weeks post-treatment, whereas the US group experienced a gradual loss of post-treatment gains. CONCLUSION: HILT combined with exercise produced greater short-term improvements in WOMAC total score than US in patients with KOA, with exploratory findings suggesting consistent benefits in pain, function, and quality of life, and with benefits maintained up to 12 weeks after the last treatment session.

Humans↗

PubMed2005

Effects of 670-nm phototherapy on development.

OBJECTIVE: The objective of the present study was to assess the survival and hatching success of chickens (Gallus gallus) exposed in ovo to far-red (670-nm) LED therapy. BACKGROUND DATA: Photobiomodulation by light in the red to near-infrared range (630-1000 nm) using low-energy lasers or light-emitting diode (LED) arrays has been shown to accelerate wound healing and improve recovery from ischemic injury. The mechanism of photobiomodulation at the cellular level has been ascribed to the activation of mitochondrial respiratory chain components resulting in initiation of a signaling cascade that promotes cellular proliferation and cytoprotecton. MATERIALS AND METHODS: Fertile chicken eggs were treated once per day from embryonic days 0-20 with 670-nm LED light at a fluence of 4 J/cm2. In ovo survival and death were monitored by daily candling (after Day 4). RESULTS: We observed a substantial decrease in overall and third-week mortality rates in the light-treated chickens. Overall, there was approximately a 41.5% decrease in mortality rate in the light-treated chickens (NL: 20%; L: 11.8%). During the third week of development, there was a 68.8% decrease in the mortality rate in light-treated chickens (NL: 20%; L: 6.25%). In addition, body weight, crown-rump length, and liver weight increased as a result of the 670-nm phototherapy. Light-treated chickens pipped (broke shell) earlier and had a shorter duration between pip and hatch. CONCLUSION: These results indicate that 670-nm phototherapy by itself does not adversely affect developing embryos and may improve the hatching survival rate.

Animals↗

PubMed2006

The role of laser fluence in cell viability, proliferation, and membrane integrity of wounded human skin fibroblasts following helium-neon laser irradiation.

BACKGROUND: In medicine, lasers have been used predominantly for applications, which are broadly termed low level laser therapy (LLLT), phototherapy or photobiomodulation. This study aimed to establish cellular responses to Helium-Neon (632.8 nm) laser irradiation using different laser fluences (0.5, 2.5, 5, 10, and 16 J/cm(2)) with a single exposure on 2 consecutive days on normal and wounded human skin fibroblasts. MATERIALS AND METHODS: Changes in normal and wounded fibroblast cell morphology were evaluated by light microscopy. Changes following laser irradiation were evaluated by assessing the mitochondrial activity using adenosine triphosphate (ATP) luminescence, cell proliferation using neutral red and an alkaline phosphatase (ALP) activity assay, membrane integrity using lactate dehydrogenase (LDH), and percentage cytotoxicity and DNA damage using the Comet assay. RESULTS: Morphologically, wounded cells exposed to 5 J/cm(2) migrate rapidly across the wound margin indicating a stimulatory or positive influence of phototherapy. A dose of 5 J/cm(2) has a stimulatory influence on wounded fibroblasts with an increase in cell proliferation and cell viability without adversely increasing the amount of cellular and molecular damage. Higher doses (10 and 16 J/cm(2)) were characterized by a decrease in cell viability and cell proliferation with a significant amount of damage to the cell membrane and DNA. CONCLUSIONS: Results show that 5 J/cm(2) stimulates mitochondrial activity, which leads to normalization of cell function and ultimately stimulates cell proliferation and migration of wounded fibroblasts to accelerate wound closure. Laser irradiation can modify cellular processes in a dose or fluence (J/cm(2)) dependent manner.

Cell Proliferation↗

PubMed2006

Clinical and experimental applications of NIR-LED photobiomodulation.

This review presents current research on the use of far-red to near-infrared (NIR) light treatment in various in vitro and in vivo models. Low-intensity light therapy, commonly referred to as "photobiomodulation," uses light in the far-red to near-infrared region of the spectrum (630-1000 nm) and modulates numerous cellular functions. Positive effects of NIR-light-emitting diode (LED) light treatment include acceleration of wound healing, improved recovery from ischemic injury of the heart, and attenuated degeneration of injured optic nerves by improving mitochondrial energy metabolism and production. Various in vitro and in vivo models of mitochondrial dysfunction were treated with a variety of wavelengths of NIR-LED light. These studies were performed to determine the effect of NIR-LED light treatment on physiologic and pathologic processes. NIRLED light treatment stimulates the photoacceptor cytochrome c oxidase, resulting in increased energy metabolism and production. NIR-LED light treatment accelerates wound healing in ischemic rat and murine diabetic wound healing models, attenuates the retinotoxic effects of methanol-derived formic acid in rat models, and attenuates the developmental toxicity of dioxin in chicken embryos. Furthermore, NIR-LED light treatment prevents the development of oral mucositis in pediatric bone marrow transplant patients. The experimental results demonstrate that NIR-LED light treatment stimulates mitochondrial oxidative metabolism in vitro, and accelerates cell and tissue repair in vivo. NIR-LED light represents a novel, noninvasive, therapeutic intervention for the treatment of numerous diseases linked to mitochondrial dysfunction.

Animals↗

PubMed2006

Photobiomodulation of pain in carpal tunnel syndrome: review of seven laser therapy studies.

In this review, seven studies using photoradiation to treat carpal tunnel syndrome (CTS) are discussed: two controlled studies that observed real laser to have a better effect than sham laser, to treat CTS; three openprotocol studies that observed real laser to have a beneficial effect to treat CTS; and two studies that did not observe real laser to have a better effect than a control condition, to treat CTS. In the five studies that observed beneficial effect from real laser, higher laser dosages (9 Joules, 12-30 Joules, 32 J/cm(2), 225 J/cm(2)) were used at the primary treatment sites (median nerve at the wrist, or cervical neck area), than dosages in the two studies where real laser was not observed to have a better effect than a control condition (1.8 Joules or 6 J/cm(2)). The average success rate across the first five studies was 84% (SD, 8.9; total hands = 171). The average pain duration prior to successful photoradiation was 2 years. Photoradiation is a promising new, conservative treatment for mild/moderate CTS cases (motor latency < 7 msec; needle EMG, normal). It is cost-effective compared to current treatments.

Carpal Tunnel Syndrome↗

PubMed2026

Photothermal-Activated Platelet-Rich Plasma Versus Conventional Platelet-Rich Plasma for Melasma: A Split-Face, Double-Blind Randomized Controlled Trial.

BACKGROUND: Melasma is a common acquired pigmentary disorder that predominantly affects women with darker skin types and substantially impairs quality of life. Current treatments are limited by variable efficacy, adverse effects, and frequent recurrence. Platelet-rich plasma (PRP) has emerged as a potential regenerative treatment through growth-factor-mediated modulation of melanogenesis. Photothermal activation, which combines photobiomodulation with controlled hypothermic conditioning, has been hypothesized to promote a more sustained growth-factor release than conventional PRP. This study compared the efficacy and safety of photothermal-activated PRP (PT-PRP) and conventional PRP (C-PRP) for melasma treatment. METHODS: This split-face, double-blind, randomized controlled trial included 26 women with epidermal or mixed-type melasma. Each participant received three monthly sessions of intradermal PRP, with PT-PRP and C-PRP injected into opposite facial sides. Outcomes were assessed at weeks 0, 4, 8, and 12 using the modified Melasma Area and Severity Index (mMASI), Mexameter melanin and erythema indices, patient satisfaction, overall improvement, and adverse events. RESULTS: Both treatments significantly reduced mMASI by week 12, with no significant between-group differences at any time point. C-PRP showed significant mMASI improvement from week 4, whereas PT-PRP reached significance from week 8. For the melanin index, PT-PRP produced a significant within-group reduction at week 12, while C-PRP did not. At week 12, PT-PRP showed a significantly lower melanin index than C-PRP. Mild injection-site bruising was the only adverse event. CONCLUSION: PT-PRP and C-PRP produced comparable clinical improvement, but PT-PRP achieved greater objective melanin reduction at week 12. PT-PRP may represent a safe alternative treatment for melasma. TRIAL REGISTRATION: Thai Clinical Trials Registry: TCTR20260318004.

Humans↗

PubMed2005

Light promotes regeneration and functional recovery and alters the immune response after spinal cord injury.

BACKGROUND AND OBJECTIVES: Photobiomodulation (PBM) has been proposed as a potential therapy for spinal cord injury (SCI). We aimed to demonstrate that 810 nm light can penetrate deep into the body and promote neuronal regeneration and functional recovery. STUDY DESIGN/MATERIALS AND METHODS: Adult rats underwent a T9 dorsal hemisection, followed by treatment with an 810 nm, 150 mW diode laser (dosage = 1,589 J/cm2). Axonal regeneration and functional recovery were assessed using single and double label tract tracing and various locomotor tasks. The immune response within the spinal cord was also assessed. RESULTS: PBM, with 6% power penetration to the spinal cord depth, significantly increased axonal number and distance of regrowth (P < 0.001). PBM also returned aspects of function to baseline levels and significantly suppressed immune cell activation and cytokine/chemokine expression. CONCLUSION: Our results demonstrate that light, delivered transcutaneously, improves recovery after injury and suggests that light will be a useful treatment for human SCI.

Animals↗

PubMed2006

Survivorship and mortality implications of developmental 670-nm phototherapy: dioxin co-exposure.

OBJECTIVE: We assessed the effect of 670-nm light therapy on dioxin-induced embryonic mortality in chickens (Gallus gallus). BACKGROUND DATA: Developmental photobiomodulation using 670-nm light-emitting diode (LED) arrays improves hatching success and increases body size in hatchling chickens. Photobiomodulation also stimulates signaling pathways resulting in improved energy metabolism, antioxidant production and cell survival. Dioxin causes embryonic mortality, including increases in the frequency of chicken embryos that pip but can't go to hatch. We hypothesized that 670-nm LED therapy would attenuate dioxin-induced embryo mortality. METHODS: Fertile chicken eggs were injected with control or 2, 20, or 200 ppt 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin) prior to the start of incubation. Half of the eggs in each dose group were treated once per day from embryonic days 0-20 with 670-nm LED light at a fluence of 4 J/cm(2). In ovo survival and hatching success were compared between dose groups and LED treatment. RESULTS: LED therapy decreased the embryonic mortality rate by 41%, resulting in increased embryonic survival and improved hatching success in eggs exposed to 200 ppt dioxin. However, at sub-lethal dioxin concentrations and in oil-treated controls, LED therapy slightly increased mortality. CONCLUSION: Overall survivorship and hatching success of chicks developmentally exposed to dioxin concentrations above the lethality threshold (>100 ppt TCDD) is improved by 670-nm LED treatment administered throughout the gestation period, but the relationship may be complicated by an LED-oil interaction.

Animals↗

PubMed2006

Brief report: embryonic growth and hatching implications of developmental 670-nm phototherapy and dioxin co-exposure.

OBJECTIVE: We assessed the effect of 670-nm light therapy on growth and hatching kinetics in chickens (Gallus gallus) exposed to dioxin. BACKGROUND DATA: Photobiomodulation has been shown to stimulate signaling pathways resulting in improved energy metabolism, antioxidant production, and cell survival. In ovo treatment with 670-nm light-emitting diode (LED) arrays improves hatching success and increases hatchling size in control chickens. Under conditions where developmental dioxin exposure is above the lethality threshold (100 ppt), phototherapy attenuates dioxin-induced early embryonic death. We hypothesized that 670-nm LED therapy would attenuate dioxin-induced developmental anomalies and increase hatching success. METHODS: Fertile chicken eggs were injected with control oil, 2, 20, or 200 ppt dioxin, or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) prior to the start of incubation. Half of the eggs in each dose group were treated once per day from embryonic days 0-20 with 670-nm LED light at a fluence of 4 J/cm2. Hatchling size, organ weights, and energy parameters were compared between dose groups and LED treatment. RESULTS: LED therapy resulted in earlier pip times (small hole created 12-24 h prior to hatch), and increased hatchling size and weight in the 200 ppt dose groups. However, there appears to be an LED-oil interaction within the oil-treated controls that results in longer hatch times and decreased liver weight within the LED control dose groups in comparison to the non-LED control dose groups. CONCLUSION: Size and hatching times suggest that the hatching success and preparedness of chicks developmentally exposed to dioxin concentrations above the lethality threshold is improved by 670-nm LED treatment administered throughout the gestation period, but the relationship may be complicated by an LED-oil interaction.

Animals↗

PubMed2006

Photobiomodulation of pain and inflammation in microcrystalline arthropathies: experimental and clinical results.

OBJECTIVE: This article presents the results of laser therapy in crystal (hydroxyapatite, calcium pyrophosphate, and urates) deposition-induced arthritis in rats and the clinical applications in humans. BACKGROUND DATA: Microcrystalline arthropathies are prevalent among geriatric patients, who are more vulnerable to the side effects of drugs. The effectiveness of laser therapy for pain relief, free of side effects, has been reported in painful conditions. METHODS: Two milligrams of each of the above-mentioned crystals was injected in both joints of the back limbs in three groups of rats; these groups were then treated with laser irradiation. Three other groups received no treatment after the injections. We determined the plasmatic levels of inflammatory markers (fibrinogen, prostaglandin E2, and TNF(alpha)), tissues (prostaglandin E(2)) and conducted anatomopathological studies. Twenty-five patients with acute gout arthritis were randomized into two groups and treated over 5 days: group A, diclofenac 75 mg orally, twice a day; and group B, laser irradiation once a day. Forty-nine patients with knee chronic pyrophosphate arthropathy were randomized into two groups and treated over 21 days; group A, diclofenac 50 mg orally, twice a day; and group B, laser irradiation once a day. Thirty patients with shoulder chronic hydroxyapatite arthropathy were randomized into two groups and treated over 21 days; group A, diclofenac 50 mg orally, twice a day; and group B, laser irradiation once a day. RESULTS: Fibrinogen, prostaglandin E(2), and TNF(alpha) concentrations in the rats injected with crystals and treated with laser decreased significantly as compared with the groups injected with crystals without treatment. Both laser therapy and diclofenac achieved rapid pain relief in patients with acute gouty arthritis without significant differences in efficacy. Laser therapy was more effective than diclofenac in patients with chronic pyrophosphate arthropathy and in patients with chronic apatite deposition disease. CONCLUSION: Laser therapy represents an effective treatment in the therapeutic arsenal of microcrystalline arthropathies.

Animals↗

PubMed2026

Effect of photobiomodulation on pain relief and functional improvement in fractures: a systematic review and meta-analysis.

INTRODUCTION: Fractures, the most common type of trauma, can cause considerable distress to patients. Pain can not only affect the comfort of fracture patients but also delay their participation in rehabilitation training. Photobiomodulation (PBM) has been associated with pain reduction and the promotion of tissue healing. This systematic review and meta-analysis aimed to evaluate the efficacy of PBM in reducing pain and promoting rehabilitation in patients with fractures. METHODS: This study was registered on PROSPERO (CRD42024591373). We systematically searched PubMed, EMBASE, the Cochrane Library and Web of Science for RCTs that investigated PBM in fractures as of August 2025. The primary outcome was the pain score. The secondary outcomes included functional and healing. RESULT: Finally, 12 and 9 studies were ultimately included in the systematic review and meta-analysis, respectively. The pooled analysis showed that the one-week pain score was lower in the PBM group than in the placebo group (MD -0.74, 95% CI -1.00, -0.47, p < 0.0001, I2 = 0%). Subgroup analysis showed that the difference between the two groups was statistically significant regardless of fracture site or acupoint irradiation. Changes in pain scores were statistically significant in both groups at different wavelength combinations. The improvement in grip strength at 4 weeks was significantly greater in PBM than in placebo (MD 5.03, 95% CI 4.29, 5.78; p < 0.0001; I2 = 0%). There were no significant differences in pain and functional scores at 4-26 weeks. Bone healing did not show differences between the two groups. No side effects reported. CONCLUSION: PBM appears to relieve short-term pain in fractures and improve grip strength in patients with upper limb fractures, but does not show significant long-term benefits. Evidence for mandibular functional recovery and bone healing remains inconsistent. Future studies should determine therapeutic parameters and their impact on bone healing and long-term functional outcomes across fracture types.

Humans↗

PubMed2005

Low power laser irradiation alters gene expression of olfactory ensheathing cells in vitro.

BACKGROUND AND OBJECTIVES: Both photobiomodulation (PBM) and olfactory ensheathing cells (OECs) transplantation improve recovery following spinal cord injury. However, neither the combination of these two therapies nor the effect of light on OECs has been reported. The purpose of this study was to determine the effect of light on OEC activity in vitro. MATERIALS AND METHODS: OECs were purified from adult rat olfactory bulbs and exposed to 810 nm light (150 mW; 0, 0.2, or 68 J/cm(2)). After 7-21 days in vitro, cells underwent immunocytochemistry or RNA extraction and RT-PCR. RESULTS: Analysis of immunolabeling revealed a significant decrease in fibronectin expression in the cultures receiving 68 J/cm(2). Analysis of gene expression revealed a significant (P < 0.05) increase in brain derived neurotrophic factor (BDNF), glial derived neurotrophic factor (GDNF), and collagen expression in the 0.2 J/cm(2) group in comparison to the non-irradiated and 68 J/cm(2) groups. OEC proliferation was also found to significantly increase in both light treated groups in comparison to the control group (P < 0.001). CONCLUSIONS: These results demonstrate that low and high dosages of PBM alter OEC activity, including upregulation of a number of neurotrophic growth factors and extracellular matrix proteins known to support neurite outgrowth. Therefore, the application of PBM in conjunction with OEC transplantation warrants consideration as a potential combination therapy for spinal cord injury.

Animals↗

PubMed2026

Photobiomodulation as an Adjunct to Resistance Training in Older Adults: A Systematic Review and Meta-Analysis.

BACKGROUND: Photobiomodulation (PBM) has been proposed as an adjunct to resistance training to enhance strength adaptations; however, findings from randomized controlled trials (RCTs) remain inconsistent. This study aimed to evaluate whether adjunctive PBM improves maximal strength gains when combined with periodized resistance training in older adults. METHODS: RCTs were identified through systematic searches of PubMed, Scopus, Embase, PEDro, Web of Science, the Cochrane Library, and CNKI from inception to January 2026. Eligible studies examined PBM delivered via low-level laser therapy or light-emitting diodes in combination with resistance training or other strength-oriented loading tasks. Prespecified meta-analyses were restricted to trials combining PBM with periodized resistance training that reported one-repetition maximum (1RM) outcomes; other studies were included in a narrative synthesis. RESULTS: Eleven RCTs (n = 456) were included. Five trials (PBM plus resistance training: n = 74; control: n = 72) met the criteria for meta-analysis. PBM combined with resistance training did not significantly improve maximal muscle strength compared with sham PBM (SMD = 0.26, 95% CI -0.08 to 0.59; p = 0.14; I2 = 4%). Subgroup analyses showed a nonsignificant trend favoring PBM for unilateral 1RM, with no effect for bilateral outcomes and no significant subgroup differences. Sensitivity analyses indicated that the unilateral effect was dependent on individual studies. In nonresistance training contexts, some studies reported potential benefits for fatigue-, recovery-, or function-related outcomes, particularly in frail or critically ill older adults, although findings were inconsistent. CONCLUSION: Current evidence does not demonstrate a clear additional benefit of PBM on maximal strength when combined with resistance training in older adults, although a small effect cannot be excluded. PBM may have selective value in improving recovery-related outcomes and supporting training tolerance in vulnerable populations. Larger, well-designed RCTs are needed to clarify its role.

Humans↗

PubMed2026

Transcranial Photobiomodulation Variables Assessment Battery: Development and Validation.

Transcranial photobiomodulation (tPBM) response variability is partly driven by biophysical characteristics such as skin tone and hair properties that attenuate photon penetration, and by lifestyle factors including sleep quality, alcohol use, and nicotine consumption that disrupt the mitochondrial and vascular pathways on which tPBM acts. To date, no validated self-report tool exists to capture these moderators systematically. To address this gap, the tPBM Variables Assessment Battery was developed and psychometrically evaluated. It integrates adapted versions of established measures (Brief Pittsburgh Sleep Quality Index, E-cigarette Dependence Scale, Hair Scale Assessment PRO, Monk Skin Tone Scale, and Heaviness of Smoking Index), validated wellbeing evaluators (Ryff's Psychological Wellbeing), and custom measures (Hairstyle Classification, Hair Color Classification). Face and content validity met recommended expert thresholds, internal consistency was acceptable across adapted subscales, and criterion validity analyses confirmed meaningful associations between the lifestyle components and PROMIS-10 global health outcomes. The battery is low-burden, digitally deployable, and psychometrically defensible, offering a practical tool for characterizing the variables most likely to moderate tPBM response in home-use studies.

Humans↗