Low-level Laser Therapy Research Articles

Development of bacteriostatic central venous port using photobiomodulation: a comparative in vitro study

Photobiomodulation (PBM) occurs when a cell is exposed to low energy intensities. A novel central venous port (CVP) with light-emitting diodes (LEDs) that emits red light with a wavelength of 680 nm via wireless energy transmission technology has been established. This comparative in vitro study examined whether PBM can reduce the growth of methicillin-resistant Staphylococcus aureus (MRSA), a common cause of central venous (CV) infections, in vitro. In this comparative in vitro study, the red light with a wavelength of 680 nm was used to irradiate an MRSA suspension in phosphate-buffered saline for 7.5, 15, 30, or 60 min in a 3.5 cm Petri dish with an area of 8.5 cm2. The total energy was 85 J at 7.5 min, 170 J at 15 min, 340 J at 30 min, and 680 J at 60 min. Six dishes for each time and 6 temperature-controlled samples were prepared. Each sample was incubated overnight at 37℃. The Shapiro-wilk test was used to determine whether the data were normally distributed. The numbers of colonies were counted and compared using one-factor ANOVA and Bonferroni’s post-hoc test. The mean numbers of colonies in the control group were 60.3, where the numbers of colonies in the irradiated group were 51.4 at 7.5 min, 53.5 at 15 min, 44.6 at 30 min, 34.3 at 60 min. The mean number of colonies in the 60 min irradiated group differed significantly from that in the control, 7.5 min, and 15 min groups. The Bonferroni’s post-hoc test showed significant difference in the number of colonies between control vs. 30 min control vs. 60 min, 7.5 min vs. 60 min, 15 min vs. 60 min. PBM with 680 nm LEDs on MRSA for 340 J at 30 min and 680 J at 60 min inhibited the growth of cell colonies. These findings support the use of photobiomodulation in Central venous port to prevent CV access port-Blood stream infection.

Photobiomodulation Enhances the Effect of Strength Training on Insulin Resistance Regardless of Exercise Volume in Mice Fed a High-Fat Diet.

The aim was to investigate the effects of different volumes of strength training (ST) in association with photobiomodulation (PBMt) in mice fed a high-fat diet (HFD) on insulin resistance (IR). Male Swiss albino mice were fed HFD and performed high- or low-volume (one-third) ST (3 days/week), associated with PBMt (660 nm + 850 nm; ~42 J delivered) or not (lights off). ST improved IR, lowered visceral adiposity and circulating cytokines, and increased skeletal muscle hypertrophy and mitochondrial activity. The smaller volume of ST did not interfere with the improvement in IR, mitochondrial activity, or inflammatory profile, but exerted a smaller effect on visceral adiposity and skeletal muscle hypertrophy. Association with PBMt further improved IR, regardless of ST volume, although it did not affect adiposity, mitochondrial activity, and the inflammatory profile. Interestingly, PBMt positively affected quadriceps, but attenuated gluteus maximus hypertrophy. The association with PBMt induced greater improvement than ST alone.

Assessing the Cost-Effectiveness of Photobiomodulation for Oral Mucositis Prevention and Treatment: A Systematic Review.

We report on the cost-effectiveness of photobiomodulation (PBM) for the prevention and treatment of oral mucositis (OM) derived from the cytotoxic effects of antineoplastic therapy. This review followed the PRISMA 2020 guidelines. A search was conducted in PubMed, Scopus, Web of Science, Embase, and OpenGrey. Articles published before 23 July 2024, were included. Randomized controlled trials (RCTs) that included patients with head and neck cancer undergoing chemotherapy and/or radiotherapy and a placebo group compared to an intervention group (PBM) were selected. The risk of bias was evaluated using the Joanna Briggs Institute tools. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach and was rated as moderate. A total of 3 RCTs and 229 patients were included. PBM may represent an additional cost in the short term, but the incremental expenses derived from the cytotoxic effects of antineoplastic therapy are greater in the medium-long term. The intervention group (PBM) showed a lower incidence of severe OM compared to the control group (placebo). PBM is a cost-effective long-term treatment, effective in preventing severe OM and improving the quality of life of cancer patients. More RCTs following the same standardized protocols are needed (registration CDR42024498825).

Dosimetry model for photobiomodulation based on anthropometric and hemodynamic variables in patients with orofacial pain post-Covid-19: Study protocol for randomized clinical trial.

Orofacial pain and tension headache are symptoms that affect a large portion of the population, compromising productivity, social ability, and functional development. The treatment for reducing painful sensation should be chosen carefully, as pharmacological treatment may bring side effects and overload the organism of patients in pain. Low-level laser therapy has been used with local and systemic [vascular] applications for pain control. However, there is still uncertainty in the literature about the ideal dosimetric parameters for photobiomodulation treatment according to patient characteristics. The objective of this project is to validate a dosimetry model based on the relationship between the effects of photobiomodulation with anthropometric and hemodynamic variables, both in local application and systemic application in patients with symptoms of orofacial pain and tension headache. For this purpose, 180 participants with orofacial pain post-covid eligible participants will be randomly assigned to Group 1-Local Photobiomodulation, Group 2-Vascular Photobiomodulation, Group 3-Placebo Local Photobiomodulation, or Group 4-Placebo Vascular Photobiomodulation [Therapy EC-DMC device, São Carlos, Brazil,- 660 nm, 100mW] using stratified block randomization. Before the application, sociodemographic information such as age, skin phototype [classified by the Fitzpatrick scale], weight, height, body mass index [BMI], oxygen saturation [SaO2], blood pressure [BP], heart rate [HR], and thickness of skin, fat, and facial muscles will be collected. During the application, we will collect local temperature, SaO2, BP, and HR. Before and after laser application, blood levels of lactate and hemoglobin, BP, and HR will be measured in the first and last session. In addition to demographic, anthropometric, and hemodynamic variables, the penetrated energy will be quantified using a power meter, and information from orofacial pain and headache symptom questionnaires will be analyzed. The Monte Carlo simulation technique will be used to systematically study the relationship between the light penetration profile into the target tissues and the most relevant variables, namely BMI, tissue layer thicknesses, and skin phototype. Light transmittance, measured in vivo and simulated, will be compared to validate a personalized dosimetry model. The results of this study contribute to validating a Monte Carlo Simulation model to calculate the appropriate dosimetry for photobiomodulation therapies in the control of patients with Post-Covid-19 orofacial pain. Trial registration number: NCT06065969.

Low-Level Laser and LED Therapy in Alopecia: A Systematic Review and Meta-Analysis.

Low-level laser/LED therapy (LLLT) has been described as a treatment option for alopecia, but no study has comprehensively reviewed its efficacy in multiple alopecia types. To review and evaluate LLLT for various alopecia types. A systematic search of PubMed/MEDLINE, Embase, and CENTRAL was conducted to identify studies assessing the effect of LLLT on patients diagnosed with alopecia. Prespecified outcome measure was the change in hair density. Meta-analysis was performed to calculate the standardized mean difference in hair density before and after LLLT compared with placebo. Thirty-eight studies were included that described 3,098 patients with androgenetic alopecia (2,930/3,098), scarring alopecia (49/3,098), alopecia areata (50/3,098), telogen effluvium (17/3,098), and chemotherapy-induced alopecia (32/3,098). The mean change in hair density increased significantly in androgenetic alopecia patients after LLLT for 4 to 26 weeks compared with placebo (<20 weeks: SMD = 1.14; 95% CI [0.51-1.78]; p = .000; I2 = 88.26%; >20 weeks: SMD = 1.44; 95% CI [0.97-1.91]; p = .000; I2 = 80.81%). Change in hair density was reported in 5 studies evaluating other alopecia types; however, statistical information was insufficient for meta-analysis. LLLT is a promising treatment option for patients with androgenetic alopecia, but future studies are needed to better understand its efficacy in other alopecia types.

The Effects of Photobiomodulation Therapy in Cubital Tunnel Syndrome, Clinical Trial.

Aim: We aimed to evaluate the effects of laser therapy together with rest splint and exercise on muscle strength, function, activities of daily living, and pain in individuals suffering from cubital tunnel syndrome (CuTS) by comparing it with placebo treatment. Materials and Methods: This prospective, single-blind, and randomized controlled study was conducted with 64 patients with CuTS in total. They were divided into two groups by randomization: Group 1 (n = 32) was provided with low-energy laser therapy + splint + exercise, and Group 2 (n = 32) was provided with low-energy sham laser therapy + splint + exercise. Patients in both groups received resting splints and nerve release exercises. Pretreatment and posttreatment (3rd week, 3rd month) evaluations were made with the Visual Analog Scale (VAS), the Quick Disability of Arm, Shoulder, and Hand Questionnaire, hand grip strength, fingertip grip strength, the Patient-Rated Ulnar Nerve Evaluation Scale (PRUNES), and Short Form-12. An electrophysiological evaluation was performed at baseline and at the 3rd month. Results: We observed significant improvements in both groups regarding pain, function, muscle strength, health profile, and quality of life in the early posttreatment (3rd week) stage and at the 3rd-month follow-up. When both groups were compared, a significant difference was determined between the VAS-Rest, VAS-Movement, PRUNES-Pain, PRUNES-Function, and PRUNES-Total parameters in the posttreatment (3rd week follow-ups), as well as PRUNES-Pain scores in the post-treatment (3rd month) stage, of the groups in favor of those in Group 1 (p < 0.05). Conclusion: The findings of our study have shown that in the treatment of CuTS, laser treatment is superior to placebo in the short term, but they have equivalent effects in the medium term. Further studies with large patient populations are needed to provide more diverse information about the therapeutic effectiveness of low-intensity laser therapy.

Effect of Photobiomodulation on an Experimental Model ofLower Limb Ischemia.

Photobiomodulation (PBM) has been shown to be promising for the promotion of angiogenesis. The present study investigated the effects of PBM on vascularization in an animal model of peripheral artery disease. Wistar rats were divided into three groups. The control group received no procedures. The ischemia group was submitted to ligation of the femoral artery of the hindleg. The ischemia + PBM group was submitted to ligation of the femoral artery followed by PBM (660 and 808 nm, 100 mW, 4 J) over the site. Animals with ischemia treated with PBM exhibited comparable results to the control group with regards to the diameter of the α-SMA+ vessels, cross-sectional area of muscle fibers, percentage of collagen and serum concentration of IL-17A, as well as similarities in terms of vertical mobility, temperature of the hindleg, number of acts of grooming, and percentage of movement, indicating a condition like that of limbs unaffected by ischemia.

Investigating the Efficacy of Bioactive Sleeves with Embedded Nano-Semiconductors in Alleviating Tendinopathy: An In Vivo Pilot Study

INTRODUCTION Low-level laser therapy (LLLT) utilizes light transmitted at near-infrared wavelengths to induce biochemical changes that promote tissue healing. The Reparel® Sleeve is a Class I Device embedded with nano-semiconductor fibers that mimic LLLT to alleviate joint and tendon pain.The purpose of this study was to determine if bioactive sleeves with nano-semiconductor fibers can objectively affect tendinopathy. METHODS 12 New Zealand white rabbits received 0.2% collagenase injections into the right Achilles tendon. Rabbits were divided into three groups: group I received a sham sleeve (n=4); group II received a Reparel® sleeve I (n=4); and group III received Reparel® sleeve II (n=4). Calf circumference measurements and thermal radiation imaging of the right lower limb were collected on days 7, 14, 21, and 28 post-injection. Two rabbits from each group were sacrificed at 14 and 28 days, and right Achilles tendons were harvested. Histological analysis using Picrosirius red staining was performed to evaluate collagen fiber organization. Immunohistochemical staining was performed to evaluate M1/M2 macrophage activity. # RESULTS A statistically significant difference in calf circumference was found at the 28-day mark between group I versus groups II and III (p &lt; 0.05). Group I displayed an average circumference of 5.2 cm while groups II and III displayed circumferences of 4.9 and 4.6 cm, respectively. A downward trend in pixel density intensity was noted in the thermal radiation imaging for both sleeve groups. Histologic staining showed that group I displayed widespread disorganization and degradation of type I and III collagen fibers, while groups II and III displayed greater organization at the 28-day mark. Immunohistochemical staining revealed greater M1 macrophage activity in group I at the 14-day mark, and greater M2 macrophage activity in groups II and III at the 28-day mark. CONCLUSION The results of our study indicate that application of bioactive nano-semiconductor sleeves had a significant effect in alleviating Achilles tendinopathy, as seen by decreased swelling, temperature, and improved histology.

FOTOBIOMODULAÇÃO NA FISIOTERAPIA PEDIÁTRICA: UMA ANÁLISE DOS ESTUDOS DOS ÚLTIMOS DEZ ANOS

Photobiomodulation (PBM), a technique that uses low-intensity light to stimulate biological processes and promote tissue recovery, has gained prominence in pediatric physiotherapy over the past decade. This study reviews clinical trials conducted in the last ten years, focusing on the positive results obtained with the application of PBM in children. The analyzed research demonstrates that PBM has beneficial effects in various pediatric conditions, such as cerebral palsy, autism spectrum disorder, nocturnal enuresis, muscular dystrophies, and orthopedic injuries. The clinical trials indicate improvements in several aspects, including motor, emotional, and cognitive functions, as well as reductions in pain and inflammation, and acceleration in muscular, skin, and oncological recovery. These findings reinforce the efficacy of photobiomodulation in pediatric physiotherapy, highlighting its potential to integrate therapeutic protocols in a non-invasive manner.

The Current Treatment for Neurodegenerative Diseases

Neurodegenerative diseases (NDs) refer to dysfunction of central nerve system, characterized by progressive loss of neuronal structure and function, ultimately resulting in decline in patients memory, motor ability, language and intelligence. The typical NDs include age related diseases like Aleimers disease (AD) and genetic diseases such as Huntingtons diseases (HD) and amyotrophic lateral sclerosis (ALS). NDs impose heavy economic burden and suffer to the enormous patients over the world, however, many types of NDs do not have a cure; existing treatments only aim to improve their symptoms. Under that condition, Gene therapy has shown potential for transporting some genetic products into the cells and correct faulty genes. Over the years, research have highlighted the promise of gene therapies using AAV vector in treating NDs. At the same time, a number of emerging therapeutic technologies for neurodegenerative diseases, such as epigenetic interventions through acetylation/deacetylation, gene therapies that target specific mRNAs or non-coding RNAs, and photo biomodulation therapies that can act on brain tissue, are also being studied. In this discussion, we explore the historical, present, and future outlook of gene therapies for neurodegenerative conditions.

Photobiomodulation improves functional recovery after mild traumatic brain injury

AbstractMild traumatic brain injury (mTBI) is a common consequence of head injury but there are no recognized interventions to promote recovery of the brain. We previously showed that photobiomodulation (PBM) significantly reduced the number of apoptotic cells in adult rat hippocampal organotypic slice cultures. In this study, we first optimized PBM delivery parameters for use in mTBI, conducting cadaveric studies to calibrate 660 and 810 nm lasers for transcutaneous delivery of PBM to the cortical surface. We then used an in vivo weight drop mTBI model in adult rats and delivered daily optimized doses of 660, 810 nm, or combined 660/810 nm PBM. Functional recovery was assessed using novel object recognition (NOR) and beam balance tests, whilst histology and immunohistochemistry were used to assess the mTBI neuropathology. We found that PBM at 810, 660 nm, or 810/660 nm all significantly improved both NOR and beam balance performance, with 810 nm PBM having the greatest effects. Histology demonstrated no overt structural damage in the brain after mTBI, however, immunohistochemistry using brain sections showed significantly reduced activation of both CD11b+ microglia and glial fibrillary acidic protein (GFAP)+ astrocytes at 3 days post‐injury. Significantly reduced cortical localization of the apoptosis marker, cleaved caspase‐3, and modest reductions in extracellular matrix deposition after PBM treatment, limited to choroid plexus and periventricular areas were also observed. Our results demonstrate that 810 nm PBM optimally improved functional outcomes after mTBI, reduced markers associated with apoptosis and astrocyte/microglial activation, and thus may be useful as a potential regenerative therapy.

Photobiomodulation effects on neuronal transdifferentiation of immortalized adipose-derived mesenchymal stem cells

Adipose-derived mesenchymal stem cells (ADMSCs) possess the ability to transform into various cell types, including neurons. It has been proposed that the optimization of this transformation can be achieved by using photobiomodulation (PBM). The objective of this laboratory-based investigation was to induce the transformation of immortalized ADMSCs (iADMSCs) into neurons with chemical triggers and then evaluate the supportive effects of PBM at two different wavelengths, 525 nm and 825 nm, each administered at a dose of 5 J/cm2, as well as the combined application of these wavelengths. The results revealed that the treated cells retained their stem cell characteristics, although the cells exposed to the green laser exhibited a reduction in the CD44 marker. Furthermore, early, and late neuronal markers were identified using flow cytometry analysis. The biochemical analysis included the assessment of cell morphology, viability, cell proliferation, potential cytotoxicity, and the generation of reactive oxygen species (ROS). The findings of this study indicate that PBM does not harm the differentiation process and may even enhance it, but it necessitates a longer incubation period in the induction medium. These research findings contribute to the validation of stem cell technology for potential applications in in vivo, pre-clinical, and clinical research environments.

Photobiomodulation suppresses allergic contact dermatitis by inhibiting T-cell activation.

Allergic contact dermatitis (ACD) is a dermal inflammatory disease caused by allergic reactions to substances that contact the skin. The hyperactivation of T cells plays an important role in its pathogenesis. Photobiomodulation (PBM) is an efficacious therapeutic approach for suppressing inflammatory diseases. This study aimed to evaluate the potentially beneficial role of PBM in ACD models and investigate its possible mechanisms. In this study, the ACD model of C57BL/6 mice was produced and treated with PBM, and the number of T cells was evaluated. In an in vitro study, naïve T cells were isolated and intervened with PBM. The markers of T cell activation were detected by flow cytometer. Transforming growth factor-β (TGF-β) and reactive oxygen species (ROS) were detected to investigate the mechanism. PBM effectively inhibited the inflammatory response by impeding the number of T cells in the ACD model. And in vitro studies showed that PBM could directly moderate the activation of naïve T cells and possess the capability to impede T cell activation via TGF-beta signaling pathway. Our finding elucidates the potential mechanism underlying the inhibitory effects of PBM in inflammatory diseases and furnishes a theoretical foundation for its clinical application.

Histological Improvement and Cytokine Levels Reduction in Patients with Oral Lichen Planus after Photobiomodulation Therapy.

Background: Oral lichen planus (OLP) is a mucocutaneous disease associated with the formation of symptomatic lesions in the mouth that are often refractory to treatment. An as-yet-unknown antigen triggers an inflammatory reaction in which various immune and non-immune cells release multiple cytokines that contribute to disease progression. The ability of photobiomodulation (PBM) to reduce the symptoms and signs of the disease has been shown, but little is known about its molecular and cellular effects. The aim of this study was to evaluate changes in pro-inflammatory cytokine levels and in histological findings in OLP patients treated with photobiomodulation therapy. Methods: Twenty OLP patients underwent PBM with diode laser (810 nm), (0.50 W, 30 s, 1.2 J/cm2), 3 times weekly for a month. Pain level and clinical scores of lesions were recorded before and after therapy. Salivary levels of IL-1β, IL-6, and TNF-α in OLP patients were measured before and after PBM and compared with those of 10 healthy controls. Biopsies were taken at the beginning and end of treatment to assess pathomorphological changes. Results: PBM significantly reduced the level of pain and clinical scores of the lesions. Salivary levels of IL-1β, IL-6, and TNF-α in OLP patients were significantly higher compared to those in healthy controls and decreased after therapy. 60% of the post-treatment OLP biopsies demonstrated histological improvement, characterized by inflammatory infiltrate reduction (50%), epithelial hyperplasia reduction (30%), epithelial thickening (15%), or epidermal-dermal attachment repair (5%). Conclusion: The effectiveness of PBM therapy in OLP patients was confirmed at the clinical, molecular, and histomorphological levels.

Photobiomodulation Therapy for Serous Pigment Epithelium Detachment in Chronic Central Serous Chorioretinopathy

PURPOSE: To report a case of giant pigment epithelium detachment (PED) secondary to chronic central serous chorioretinopathy (cCSC) successfully treated with photobiomodulation (PBM). METHODS: Case report. RESULTS: A 55-year-old man complained a worsening of vision in the left eye (LE) over the last 18 months. A complete ophthalmological evaluation encompassing best corrected visual acuity (BCVA) measurement, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF), fluorescein angiography (FA) and microperimetry (MP) was performed. SD-OCT showed several small PEDs around the macula in the right eye and a giant macular serous PED with subretinal fluid (SRF) in the LE. FA disclosed multiple hyperfluorescent roundish areas in the posterior pole bilaterally, with a macular pooling in the LE. A diagnosis of cCSC was made, and patient underwent PBM with one session for week for four weeks, followed by one session bi-weekly for two months. SD-OCT of the LE showed a gradual flattening of the macular PED at 3 months, with a complete regression of the latter and of the SRF at 6- and 12-month follow up with no residual signs of chorioretinal atrophy on FAF. BCVA improved from 20/80 at baseline to 20/25 at the last follow up, and this functional improvement was further confirmed by MP. CONCLUSIONS: PBM can be considered a safe and effective treatment strategy for the management of cCSC with SRF and serous PED.

Low-power red laser and blue LED modulate telomere maintenance and length in human breast cancer cells.

Cancer cells have the ability to undergo an unlimited number of cell divisions, which gives them immortality. Thus, the cancer cell can extend the length of its telomeres, allowing these cells to divide unlimitedly and avoid entering the state of senescence or cellular apoptosis. One of the main effects of photobiomodulation (PBM) is the increase in the production of adenosine triphosphate (ATP) and free radicals, mainly reactive oxygen species (ROS). Existent data indicates that high levels of ROS can cause shortening and dysfunctional telomeres. Therefore, a better understanding of the effects induced by PBM on cancer cell telomere maintenance is needed. This work aimed to evaluate the effects of low-power red laser (658nm) and blue LED (470nm) on the TRF1 and TRF2 mRNA levels and telomere length in human breast cancer cells. MCF-7 and MDA-MB-231 cells were irradiated with a low-power red laser (69J cm-2, 0.77W/cm-2) and blue LED (482J cm-2, 5.35W/cm-2), alone or in combination, and the relative mRNA levels of the genes and telomere length were assessed by quantitative reverse transcription polymerase chain reaction. The results suggested that exposure to certain red laser and blue LED fluences decreased the TRF1 and TRF2 mRNA levels in both human breast cancer cells. Telomere length was increased in MCF-7 cells after exposure to red laser and blue LED. However, telomere length in MDA-MB-231 was shortened after exposure to red laser and blue LED at fluences evaluated. Our research suggests that photobiomodulation induced by red laser and low-power blue LED could alter telomere maintenance and length.

Myelodysplasia Rehabilitation in Children: a Review

INTRODUCTION. 1.5 thousand children with myelodysplasia (MD) are born in Russia every year. To improve the quality of life, most of them need lifelong medical supervision and rehabilitation. The topic of medical rehabilitation in MD in children is poorly covered. AIM. To search and analysis published data on the rehabilitation of children with MD identify the most effective methods. MATERIALS AND METHODS. The collection and analysis of publications on this topic from the PubMed and eLibrary databases published from 2014 to 2024 was carried out. Earlier fundamental works on secondary disorders in myelodysplasia and Spina bifida were also included in the review. A total of 512 publications in PubMed and 1096 publications in eLibrary were analyzed, 584 of them were unique. Publications of reviews, systematic reviews and clinical observations were included. RESULTS AND DISCUSSION. Rehabilitation for MD in children is multidisciplinary in nature, a violation of the structure of the nervous system entails, already in utero, the formation of deformities of the musculoskeletal system, combined changes in the functioning of the lower urinary tract and intestines. It is known that rehabilitation started from an early age helps to master motor skills in a timely manner, contributes to the prevention of metabolic syndrome, contractures, pressure sores, urodynamic disorders and constipation. There are different approaches regarding the intensity of physical activity during the day and week, following the recommendations of the World Health Organization (WHO), children should exercise for more than 60 minutes a day. Physical exercises should be carried out from the perspective of the concept of neuroplasticity and enhanced by the influence of magnetic stimulation, low-intensity laser, electromyostimulation, vibration therapy. It will be possible to effectively use acupuncture and massage. In addition, it is important to include urological and orthopedic care in medical rehabilitation from an early age. CONCLUSION. Due to the high disability, there is a question of effective methods for improving rehabilitation potential and improving the standard of living. Among the described methods, physiotherapy is distinguished, including therapeutic exercises, magnetic stimulation, low-intensity laser therapy, electromyostimulation, and ergotherapy. It is necessary to continue to study the effectiveness of the use of various physical factors in children with MD.

The Efficacy of Low-Level Laser Therapy on the Healing of Oral Wounds: A Systematic Review

The Efficacy of Low-Level Laser Therapy on the Healing of Oral Wounds: A Systematic Review

Enhancing osteoblast differentiation and bone repair: The priming effect of photobiomodulation on adipose stromal cells

Cellular therapy using adipose tissue–derived mesenchymal stromal cells (at-MSCs) has garnered attention for the treatment of bone defects. Therefore, preconditioning strategies to enhance the osteogenic potential of at-MSCs could optimize cell therapy outcomes, and photobiomodulation (PBM) therapy has emerged as an effective, noninvasive, and low-cost alternative. This study explored the impacts of PBM on at-MSCs differentiation and the subsequent repair of bone defects treated with cell injection. Rat at-MSCs were cultured and irradiated (at-MSCsPBM) following the PBM protocol (660 nm; 20 mW; 0.714 W/cm2; 0.14 J; 5 J/cm2). Cellular differentiation was assessed based on the expression of gene and protein markers. Reactive oxygen species (ROS) were detected using fluorescence. At-MSCsPBM were injected into 5-mm calvarial lesions, and bone formation was analyzed using micro-CT and histological evaluations. At-MSCs were used as control. Data were analyzed using the ANOVA or t-test. At-MSCsPBM exhibited high levels of gene and protein runt-related transcription factor-2 (Runx2) and alkaline phosphatase (Alp) expression. PBM increased ALP activity and significantly reduced ROS levels. In addition, PBM increased the expression of Wnt pathway–associated genes. In vivo, there was an increase in the morphometric parameters, including bone volume, percentage of bone volume, bone surface area, and trabecular number, in at-MSCsPBM-treated defects compared with those in the control. These findings suggest that PBM enhances the osteogenic potential of at-MSCs, thereby supporting the advancement of improved cellular therapies for bone regeneration.

Low level laser therapy alleviates mechanical allodynia in a postoperative and neuropathic pain model and alters the levels of inflammatory factors in rats.

This study aimed to investigate the analgesic and preventive effect of low-level laser therapy (LLLT) on the incisional pain model and spinal nerve ligation (SNL) model in rats and identify the possible mechanisms of action. Male Sprague-Dawley rats were used, divided into different treatment groups. The single application group received LLLT before or after skin incision or SNL. The consecutive application group received LLLT for six consecutive days post-incision, three days pre-incision, or three consecutive days pre-SNL. The control group underwent skin incision or SNL without LLLT. The von Frey test was used to quantify the pain associated with mechanical allodynia. Pro-inflammatory cytokine level and alterations in nerve growth factor (NGF) expression were measured by using ELISA and immunohistochemistry, respectively in the skin, muscle of the paw, and spinal cord dorsal horn (SCDH). In the incisional pain model, LLLT showed significant analgesic and preventive effect. LLLT ameliorated SNL-induced mechanical allodynia but LLLT had no preventive effect. LLLT decreased interleukin-1β (IL-1β) expression levels in the skin, muscle, and SCDH and reduced the optical density of skin and spinal cord NGF in the incisional pain model. LLLT alleviated incisional pain and neuropathic pain caused by SNL in rats, and reduced the levels of IL-1β and NGF in the peripheral tissue and SCDH in the incisional pain model. LLLT might be effective in patients with post-operative pain and peripheral neuropathic pain.