Effects Of Photobiomodulation Research Articles

Effect of Novel Laser Shoe Photobiomodulation on Neuropathic Pain and Plantar Pressure Profile in Type 2 Diabetes Mellitus with Peripheral Neuropathy.

Photobiomodulation (PBM) or Low-level laser is used to treat diabetic foot complications. The existing method of laser application to the foot did not cover the foot's entire area to improve the foot's microcirculation. Therefore, we have developed a cost-effective Special LASER Shoe device, focusing exclusively on the entire foot region to manage neuropathic pain and other symptoms in individuals with type 2 diabetes mellitus. The main objective of the present study was to evaluate the effect of this newly developed special laser shoe PBM on neuropathic pain and plantar pressure profile in individuals with type 2 diabetes mellitus with neuropathy. We included 60 participants with diabetic peripheral neuropathy of both genders and age more than 20 years. Participants were treated with PBM by a specially designed novel Laser Shoe. Outcomes were clinical variables like Vibration Perception Threshold (VPT), Visual Analogue Scale (VAS), Michigan neuropathy screening instrument A&B, Ankle-Brachial Index (ABI), and Static dynamic gait parameters. Participants were with an average age of 62, and the average duration of diabetes was 11 years. Analysis showed a significant difference in VPT, VAS, Michigan neuropathic screening inventory, and ankle-brachial index. (P < 0.05). We conclude that Novel laser shoe photobiomodulation using 'Laser Shoe' effectively reduces peripheral neuropathic pain. It is also effective in reducing average and maximum plantar pressure. Reduction in neuropathic pain and improvement in plantar pressure distribution can reduce further complications.

Biphasic photobiomodulation of inflammation in mouse models of common wounds, infected wounds, and diabetic wounds

Bidirectional photobiomodulation (PBM) therapy is an active research area. However, most studies have focused on its dependence on optical parameters rather than on its tissue-dependent effects. We constructed mouse models of wounds in three inflammatory states (normal, low, and high levels of inflammations) to assess the bidirectional regulatory effect of PBM on inflammation. Mice were divided into three groups to prepare common wounds, diabetic wounds, and bacteria-infected wounds. The same PBM protocol was used to regularly irradiate the wounds over a 14 d period. PBM promoted healing of all three kinds of wounds, but the inflammatory manifestations in each were significantly different. In common wounds, PBM slightly increased the aggregation of inflammatory cells and expression of IL-6 but had no effect on the inflammatory score. For wounds in a high level of inflammation caused by infection, PBM significantly increased TNF-α expression in the first 3 d of treatment but quickly eliminated inflammation after the acute phase. For the diabetic wounds in a low level of inflammation, PBM intervention significantly increased inflammation scores and prevented neutrophils from falling below baseline levels at the end of the 14 d observation period. Under fixed optical conditions, PBM has a bidirectional (pro- or anti-inflammatory) effect on inflammation, depending on the immune state of the target organism and the presence of inflammatory stimulants. Our results provide a basis for the formulation of clinical guidelines for PBM application.

Effectiveness of 780 nm photobiomodulation as adjunct treatment for bone exposed fractures: A pilot study on radiograph, pain, and cytokines analysis.

The aim of this study was to evaluate the effectiveness of photobiomodulation with a 780 nm laser as an adjunct to surgical treatment in the regeneration of bone fractures. Twenty patients diagnosed with open fractures in the lower limbs were selected and randomly divided into two groups: control and LLLT. LLLT parameter: 780 nm, 0.04 cm2 of light beam diameter, 40 mW of power, 10 s per point, 0.4 J of energy, fluence of 10 J/cm2 and irradiance of 1 W/cm2. The evaluated data were: pain, using McGill scale, use of analgesics and anti-inflammatories, levels of cytokines TNF-α, IFN-γ, IL-1β, IL-10, and IL-17, and bone level regeneration. Data were analyzed using Wilcoxon and Mann-Whitney tests (5%). We can conclude that LLLT was effective as an adjuvant in the bone fracture regeneration process, altered IL-1β levels, reduced the use of analgesics and anti-inflammatories, reducing the pain pattern throughout the sessions.

Effects of low‑power red laser and blue LED on mRNA levels from DNA repair genes in human breast cancer cells.

Photobiomodulation (PBM) induced by non-ionizing radiations emitted from low-power lasers and light-emitting diodes (LEDs) has been used for various therapeutic purposes due to its molecular, cellular, and systemic effects. At the molecular level, experimental data have suggested that PBM modulates base excision repair (BER), which is responsible for restoring DNA damage. There is a relationship between the misfunction of the BER DNA repair pathway and the development of tumors, including breast cancer. However, the effects of PBM on cancer cells have been controversial. Breast cancer (BC) is the main public health problem in the world and is the most diagnosed type of cancer among women worldwide. Therefore, the evaluation of new strategies, such as PBM, could increase knowledge about BC and improve therapies against BC. Thus, this work aims to evaluate the effects of low-power red laser (658nm) and blue LED (470nm) on the mRNA levels from BER genes in human breast cancer cells. MCF-7 and MDA-MB-231 cells were irradiated with a low-power red laser (69Jcm-2, 0.77 W cm-2) and blue LED (482Jcm-2, 5.35 W cm-2), alone or in combination, and the relative mRNA levels of theAPTX,PolB, andPCNAgenes were assessed by reverse transcription-quantitative polymerase chain reaction. The results suggested that exposure to low-power red laser and blue LED decreased the mRNA levels fromAPTX,PolB, andPCNAgenes in human breast cancer cells. Our research shows that photobiomodulation induced by low-power red laser and blue LED decreases the mRNA levels of repair genes from the base excision repair pathway in MCF-7 and MDA-MB-231 cells.

Effect of Photobiomodulation With Laser on The Composition, Production and Quality of The Milk of Cows with Clinical Mastitis

Objective: This study assesses the impact of LASER photobiomodulation (808nm at 1400 mW and 637nm at 100 mW, with a 2-minutes irradiation per wavelength, total dose: 1.4 W/cm² and 1 W/cm², respectively) on milk composition and quality in cows suffering from clinical mastitis. Theoretical Framework: Research indicates LASER photobiomodulation's potential in improving animal health, yet there’s a gap in specific therapeutic protocols for treating clinical mastitis in cows using this technology. Methodology: The study involved 20 cows with clinical mastitis. Their mammary quarters were assessed for fat and protein composition, Somatic Cell Count, Urea Nitrogen levels, Microbiological Culture, and Antibiotic Sensitivity and Milk production. Comparisons were made between two groups over six days: one receiving a combination of antibiotics and LASER photobiomodulation therapy, and a control group receiving only antibiotics. Results and Conclusion: LASER photobiomodulation significantly aided the treatment of clinical mastitis in conjunction with antibiotics. This combination not only helped in curing mastitis but also reduced the Somatic Cell Count and increased milk production, marking it as a viable alternative therapy. Implications of the Research: This study contributes to establishing a more effective treatment protocol for clinical mastitis, combining photobiomodulation with traditional antibiotic methods. Originality/Value: This pioneering research showcases the use of a photobiostimulation device as a supplementary treatment for controlling clinical mastitis in dairy cows, integrated with antibiotic therapy. It underscores the enhanced efficiency of such combined treatments, contributing to the Sustainability.

The Effectiveness of Photobiomodulation Using 940-nm Diode Laser for Reducing Pain, Swelling and Trismus After Third Molar Surgery: A Single-Blinded Randomized Control Trial

The Effectiveness of Photobiomodulation Using 940-nm Diode Laser for Reducing Pain, Swelling and Trismus After Third Molar Surgery: A Single-Blinded Randomized Control Trial

Photobiomodulation Recovers the Submandibular Gland in Vismodegib-Treated Rats.

Objective: The submandibular gland (SMG) produces the most saliva, and factors such as aging and chemotherapy can affect its structure and function. However, there are only temporary treatments available for salivary hypofunction. This study aimed to evaluate the effects of photobiomodulation (PBM) on the function of SMG by using a rat animal model and vismodegib, an antagonist of the sonic hedgehog (SHH) pathway. Methods: Vismodegib (10 mg/kg) drug was gavaged orally for 14 days in rats to significantly decrease the SHH signaling proteins [SHH, protein patched homolog 1 (PTCH1), smoothened protein (SMO), glioma-associated oncogene homolog 1 (GLI1)], induce damage in SMG tissue, and affect salivary functional markers AQP5 and Keratin5. After that, in conjunction with vismodegib administration, PBM was performed using an 850 nm high-power light-emitting diode (LED) device treated daily for 6 days at varying total energy densities of 60, 120, and 180 J/cm2 in at least 3 rats per group. The test results were confirmed by Western blot, immunofluorescence staining, and hematoxylin and eosin staining, and the statistics were t-test or one-way analysis of variance (ANOVA) with Tukey's multiple comparisons tests. Results: Significant decreases in the expression of SHH-related proteins (PTCH1, SMO, GLI1, p < 0.05) with damage of SMG ductal cells were observed with vismodegib administration. However, a significant increase in the expression levels of SHH-related proteins (SHH, SMO, GLI1, p < 0.05) and recovery of SMG ductal cells damaged after vismodegib administration were observed for PBM-treated groups. Salivary functional marker AQP5 also showed the same increase or decrease. Conclusions: This study found that vismodegib damages SMG ductal cells and decreases SHH-related proteins and associated salivary functional markers. Also, 850 nm high-power LED recovered the damaged structure of SMG and increased SHH-related proteins and salivary functional markers. The study results suggest that PBM can restore SMG structure and function through SHH signaling.

The Effects In Vitro of Photobiomodulation Over Fibroblasts and Extracellular Matrix.

Objective: The objective of this study is to evaluate the potential effects of photobiomodulation (PBM) on cell proliferation and extracellular matrix production of human fibroblasts (FN1) cultured in 2D. Background: Patients with healing difficulties suffer injuries that take time to recover. In addition, aging can be seen in our faces daily when we look in the mirror; in both situations, collagen production is reduced. Fibroblasts act in the beginning and at the end of the inflammation phase, signaling to immune agents, and platelets, and producing collagen, coordinating repair. PBM increases cell viability, proliferation, and mRNA production. Methods: Human fibroblasts were irradiated three times after cell seed (after 24, 48, and 72 h) using a gallium-aluminum arsenideGaAlAs low-level laser (LLL). Cell viability, proliferative response, synthesis of collagen types I and III, and soluble collagen production were analyzed. The statistical significance of differences between groups was determined using unpaired one-way analysis of variance (ANOVA) p < 0.05. Results: PBM increased significantly the number of fibroblasts, and the production of collagen types I (Col I) and III (Col III), after three sessions of LLL with 2.5 J per session, every 24 h, for 3 consecutive days; total energy delivered after 72 h is 7.5 J. Conclusions: This energy density of LLL increases fibroblast proliferation and collagen production in vitro without side effects.

Outcomes of whole-body photobiomodulation on pain, quality of life, leisure physical activity, pain catastrophizing, kinesiophobia, and self-efficacy: a prospective randomized triple-blinded clinical trial with 6 months of follow-up.

The management of fibromyalgia (FM) symptoms on a global scale remains a complex endeavor. This study endeavors to assess the impact of whole-body photobiomodulation (PBM) compared to placebo PBM on pain, functionality, and psychological symptoms in individuals afflicted with fibromyalgia. The primary objectives of this research were to conduct a comparative analysis of the effects of whole-body photobiomodulation (PBM) and placebo PBM on pain, functionality, and psychological symptoms in patients suffering from fibromyalgia (FM). A total of 42 subjects were recruited from a private care practice for participation in this triple-blinded, placebo-controlled, randomized clinical trial. Participants underwent 12 treatment sessions, and assessments were conducted at various intervals, including baseline (T0), midway through the 12-session treatment (T1), at the completion of the 12 sessions (T2), and follow-ups at 2 weeks (T3), 3 months (T4), and 6 months (T5). Statistical analysis revealed significant reductions in pain at T2, T3, and T5. Additionally, quality of life exhibited marked improvements after sessions at T1, T2, T3, T4, and T5. Leisure activity also demonstrated statistically significant improvements at T2, T3, T4, and T5. Furthermore, kinesiophobia showed significant differences between groups immediately after treatment at T2, T3, T4, and T5. Self-efficacy, when compared between groups, demonstrated significant differences at T3, T4, and T5 (two weeks after treatment). Lastly, pain catastrophizing exhibited significant differences only at T5. The findings of this study indicate that whole-body PBM treatment for 4 weeks resulted in significant pain reduction and improved quality of life in individuals suffering from FM. Furthermore, kinesiophobia and self-efficacy demonstrated improvements in both short-term and long-term assessments, while pain catastrophizing showed improvement at the 6-month follow-up. Consequently, whole-body PBM emerges as a promising multifactorial treatment option for FM patients, though further studies are required to validate and strengthen these results.Clinical Trial Registration:Clinicaltrials.gov, NCT0424897.

Photobiomodulation and conditioned medium of adipose-derived stem cells for enhancing wound healing in rats with diabetes: an investigation on the proliferation phase.

This investigation tried to evaluate the combined and solo effects of photobiomodulation (PBM) and conditioned medium derived from human adipose tissue-derived stem cells (h-ASC-CM) on the inflammatory and proliferative phases of an ischemic infected delayed healing wound model (IIDHWM) in rats with type I diabetes mellitus (TIDM). The present investigation consisted of four groups: group 1 served as the control, group 2 treated with h-ASC-CM, group 3 underwent PBM treatment, and group 4 received a combination of h-ASC-CM and PBM. Clinical and laboratory assessments were conducted on days 4 and 8. All treatment groups exhibited significantly higher wound strength than the group 1 (p = 0.000). Groups 4 and 3 demonstrated significantly greater wound strength than group 2 (p = 0.000). Additionally, all therapeutic groups showed reduced methicillin -resistant Staphylococcus aureus (MRSA) in comparison with group 1 (p = 0.000). While inflammatory reactions, including neutrophil and macrophage counts, were significantly lower in all therapeutic groups rather than group 1 on days 4 and 8 (p < 0.01), groups 4 and 3 exhibited superior results compared to group 2 (p < 0.01). Furthermore, proliferative activities, including fibroblast and new vessel counts, as well as the measurement of new epidermal and dermal layers, were significantly increased in all treatment groups on 4 and 8 days after the surgery (p < 0.001). At the same times, groups 4 and 3 displayed significantly higher proliferative activities compared to group 2 (p < 0.001). The treatment groups exhibited significantly higher mast cell counts and degranulation phenotypes in comparison with the group 1 on day 4 (p < 0.05). The treatment groups showed significantly lower mast cell counts and degranulation phenotypes than group 1 on day 8 (p < 0.05).The combined and individual application of h-ASC-CM and PBM remarkably could accelerate the proliferation phase of wound healing in the IIDHWM for TIDM in rats, as indicated by improved MRSA control, wound strength, and stereological evaluation. Furthermore, the combination of h-ASC-CM and PBM demonstrated better outcomes compared to the individual application of either h-ASC-CM or PBM alone.

Identification by methods of steady-state and kinetic spectrofluorimetry of endogenous porphyrins and flavins sensitizing the formation of reactive oxygen species in cancer cells.

The question about acceptor molecules of optical radiation that determine the effects of photobiomodulation in relation to various types of cells still remains the focus of attention of researchers. This issue is most relevant for cancer cells, since, depending on the parameters of optical radiation, light can either stimulate their growth or inhibit them and lead to death. This study shows that endogenous porphyrins, which have sensitizing properties, may play an important role in the implementation of the effects of photobiomodulation, along with flavins. For the first time, using steady-state and kinetic spectrofluorimetry, free-base porphyrins and their zinc complexes were discovered and identified in living human cervical epithelial carcinoma (HeLa) cells, as well as in their extracts. It has been shown that reliable detection of porphyrin fluorescence in cells is hampered by the intense fluorescence of flavins due to their high concentration (micromolar range) and higher (compared to tetrapyrroles) fluorescence quantum yield. Optimization of the spectral range of excitation and the use of extractants that provide multiple quenching of the flavin component while increasing the emission efficiency of tetrapyrroles makes it possible to weaken the contribution of the flavin component to the recorded fluorescence spectra.

Evaluating the effect of strontium ranelate and photobiomodulation on cementogenic and osteogenic differentiation of buccal fat pad-derived stem cells: An in vitro study.

This study aimed to analyze the impact of strontium ranelate (Str), photobiomodulation (PBM), or their combination of the proliferation, osteogenic differentiation, and cementogenic differentiation of buccal fat pad-derived stem cells. BFPdSCs were exposed to one of the following interventions: (1) PBM (660 nm), (2) PBM (660 nm) + Str, (3) PBM (880 nm), (4) PBM (880 nm) + Str, (5) Str. All study groups had significantly higher osteogenic differentiation than the control group (p < 0.05), and no significant difference existed between the 660 and 808 nm groups (p = 0.97). Compared to the Str group, 660 nm and 880 nm group samples had significantly lower osteogenic differentiation (p < 0.0001), while other groups did not show a significant difference. Regarding cementogenic differentiation, the 660 nm group showed higher values than the 808 nm group (p < 0.01). Compared with the Str group, 660 nm, 660 nm + Str, and 808 nm + Str groups showed significantly higher gene expression (p < 0.05). In the case of osteogenic differentiation, although photobiomodulation alone had a lower inducing effect than strontium ranelate, combining 808 nm diode lasers and strontium ranelate may provide the best results. Moreover, using a 660 nm diode laser and exposing stem cells to strontium ranelate can be the most effective approach to induce cementogenic differentiation.

Effects of Photobiomodulation Using Near-Infrared Light on the Dentin and Periodontal Ligament in a Beagle Model

In this study, we investigated the effect of photobiomodulation (PBM) using near-infrared light on the dentin and periodontal ligament in a beagle model. We utilized a specific PBM device to irradiate NIR light with a wavelength of 810 nm and an energy density of 80.22 mJ/cm2. The device’s settings were optimized for a frequency of 300 Hz and a 30% duty cycle, allowing precise and controlled light exposure. Through a comprehensive analysis involving micro-computed tomography, scanning electron microscopy, and hematoxylin and eosin staining, we demonstrated increased odontoblast activity at the pulp–dentin interface in PBM-treated samples. This increased activity may be postulated to potentially contribute to alleviating dental hypersensitivity through the differentiation of dental pulp stem cells and the promotion of vascular development within the odontoblast layer. Moreover, our observations also indicated an improvement in the strength and integrity of fibrous connective tissue within the periodontal ligament. These findings highlight the potential of PBM with specific parameters applied using NIR as a valuable treatment method for tooth tissue regeneration. It shows particular promise in the treatment of dental diseases associated with dentin and periodontal ligament damage and offers a new perspective in the management of tooth hypersensitivity and other related dental diseases.

An invitro study on the effects of photobiomodulation by diode lasers (red, infrared, and red-infrared combination) on periodontal ligament mesenchymal stem cells treated with bisphosphonates.

This study evaluated the effect of photobiomodulation therapy (PBMT) using 660 and 808 nm diode lasers (individual and in combination) on periodontal ligament mesenchymal stem cells (PDLSCs) in the presence of zoledronic acid (ZA). PDLSCs were cultured for 48 h in DMEM complete medium containing 5 μM ZA. PBMT was done three times with a 24-h interval in groups 1 (660 nm, 5 J/cm2), 2 (880 nm, 3 J/cm2), and 3 (660 + 808 nm) either in normal or ZA-treated culture medium. Control groups did not receive PBMT. Twenty-four hours post-irradiation, cell proliferation and expression of RANKL and OPG were assessed using MTT and real-time PCR tests, respectively. The results showed a significant decrease in cell viability in ZA-treated cells (p < 0.001). Additionally, ZA induced the expression of OPG (p = 0.03) while reducing RANKL (p < 0.001). Cell proliferation was significantly increased in 808 and 660 + 808 nm groups. Moreover, all PBMT groups could significantly increase and decrease the RANKL and OPG, respectively, in the presence of ZA (all p < 0.001). A combination of 660 + 808 nm showed the highest effects on both genes. In conclusion, it seems that PBMT can modulate the effects of ZA by inducing PDLSC proliferation and increasing RANKL-to-OPG gene expression ratio.

Effectiveness of Photobiomodulation With Low-Level Laser Therapy on the Implant Stability Quotient at Different Time Intervals: A Randomized Clinical Trial.

Background Photobiomodulation techniques, particularly low-level laser therapy (LLLT), have gained traction due to their ability to accelerate osseointegration by stimulating cellular metabolism and promoting tissue healing. This study explores the effectiveness of LLLT around dental implants at various intervals after placement. Using resonance frequency analysis (RFA), the implant stability quotient (ISQ) was measured to assess implant stability. Methodology This split-mouth, randomized, single-blinded clinical trial included 20 participants undergoing dental implant placement. The test group received LLLT while the control group had no laser treatment. Implant stability was assessed using RFA at one, two, four, and twelve weeks post-implant placement. Statistical analysis involved descriptive statistics, repeated-measures analysis of variance (ANOVA), and t-tests. Results The repeated-measures ANOVA analysis showed significant differences in the ISQ values between the LLLT group and the control group at two weeks and three months post-implant placement. The LLLT group exhibited higher ISQ values, indicating greater implant stability and improved osseointegration compared to the control group. These findings suggest the potential benefits of LLLT in enhancing dental implant outcomes. Conclusions LLLT shows promise in improving dental implant outcomes, with enhanced stability and osseointegration. Further research is needed to validate these results and integrate LLLT into routine dental implant procedures.

Low-level Nd:YAG laser inhibiting inflammation and oxidative stress in human gingival fibroblasts via AMPK/SIRT3 axis

ObjectivePhotobiomodulation is extensively employed in the management of chronic inflammatory diseases such as periodontitis because of its anti-inflammatory and antioxidant effects. This study used low-level Nd:YAG laser to investigate the mechanism of photobiomodulation as well as the role of adenosine monophosphate-activated protein kinase (AMPK) and Sirtuins (SIRT) 3 in it, providing new clues for the treatment of periodontitis. MethodsHuman gingival fibroblasts (HGFs) were extracted from gingiva and stimulated with LPS. The suitable parameters of Nd:YAG laser were chosen for subsequent experiments by detecting cell viability. We assessed the level of inflammation and oxidative stress as well as AMPK and SIRT3. The mechanism for AMPK targeting SIRT3 modulating the anti-inflammatory and antioxidant effects of photobiomodulation was explored by the AMPK inhibitor (Compound C) test, cell transfection, western blot, and immunofluorescence. ResultsHGFs were isolated and identified, followed by the identification of optimal Nd:YAG laser parameters (60 mJ, 15 Hz, 10s) for subsequent experimentation. With this laser, inflammatory factors (IL-6, TNF-α, COX2, and iNOS) decreased as well as the phosphorylation and nuclear translocation of NFκB-P65. SOD2 was up-regulated but reactive oxygen species (ROS) was down-regulated. The laser treatment exhibited enhancements in AMPK phosphorylation and SIRT3 expression. The above effects could all be reversed by Compound C. Silencing AMPK or SIRT3 by siRNA, the down-regulation of COX2, iNOS, and ROS by laser was inhibited. SIRT3 was down-regulated when the AMPK was silenced. ConclusionLow-level Nd:YAG laser activated AMPK-SIRT3 signaling pathway, facilitating the anti-inflammatory and antioxidative activity.

Effects of Laser Photobiomodulation on the Regeneration of Bone Defects Grafted with Bio-Oss® Xenograft: a Systematic Review of Animal Models

Abstract Photobiomodulation with low-power laser has stood out for its effects on metabolism, bone regeneration and its notable osteogenic potential. This study aimed to review the literature regarding the effectiveness of photobiomodulation with low-level laser therapy (LLLT) in inducing bone regeneration in sites grafted with Bio-Oss®, through experimental animal studies. It was a systematic review, based on a search performed in PubMed/Medline, Google Scholar, Capes Journals, SciELO and BIREME databases. Descriptors were selected from DeCS/MeSH and the PICOS strategy was applied. Experimental studies published from 2012 to 2023 were included, according to the PRISMA parameters, registered in the PROSPERO platform. The SYRCLE risk of bias tool was used. Using the search strategy, 1352 articles were identified, and five were included in this qualitative synthesis. Despite the divergence observed in the laser dosimetry protocols adopted by the studies, it was evident that laser photobiomodulation associated with the use of Bio-Oss® promotes bone density gains and a considerable increase in the amount of mineralized tissue in bone defects induced in animals. In addition, the use of laser alone has contributed to an improvement in bone formation in non-grafted sites. The data presented show a potential for improvement in the bone reconstruction process by associating photobiomodulation with low-level laser with the application of the Bio-Oss® inorganic bovine bone xenograft. Keywords: Low-Level Laser Therapy. Photobiomodulation Therapy. Xenografts. Bio-Oss. ResumoA fotobiomodulação com laser de baixa potência tem se destacado pelos seus efeitos no metabolismo, na regeneração óssea e por seu notável potencial osteogênico. Este estudo teve como objetivo revisar a literatura sobre a eficácia da fotobiomodulação com laserterapia de baixa potência (LLLT) na indução da regeneração óssea em locais enxertados com Bio-Oss®, por meio de estudos experimentais em animais. Trata-se de uma revisão sistemática, baseada em busca realizada nas bases de dados PubMed/Medline, Google Acadêmico, Periódicos Capes, SciELO e Bireme. Os descritores foram selecionados no DeCS/MeSH e aplicada a estratégia PICOS. Foram incluídos estudos experimentais publicados de 2012 a 2023, segundo parâmetros PRISMA, cadastrados na plataforma PROSPERO. Foi utilizada a ferramenta de risco de viés SYRCLE. Utilizando a estratégia de busca, foram identificados 1.352 artigos, e cinco foram incluídos nesta síntese qualitativa. Apesar da divergência observada nos protocolos de dosimetria do laser adotados pelos estudos, ficou evidente que a fotobiomodulação laser associada ao uso do Bio-Oss® promove ganhos de densidade óssea e aumento considerável na quantidade de tecido mineralizado em defeitos ósseos induzidos em animais. Além disso, o uso isolado do laser contribuiu para uma melhora na formação óssea em locais não enxertados. Os dados apresentados mostram potencial de melhoria no processo de reconstrução óssea através da associação da fotobiomodulação com laser de baixa intensidade com a aplicação do xenoenxerto ósseo bovino inorgânico Bio-Oss®. Palavras-chave: Terapia com Luz de Baixa Intensidade. Terapia de Fotobiomodulação. Xenoenxertos. Bio-Oss.

Photobiomodulation inhibits the expression of chondroitin sulfate proteoglycans after spinal cord injury via the Sox9 pathway.

Both glial cells and glia scar greatly affect the development of spinal cord injury and have become hot spots in research on spinal cord injury treatment. The cellular deposition of dense extracellular matrix proteins such as chondroitin sulfate proteoglycans inside and around the glial scar is known to affect axonal growth and be a major obstacle to autogenous repair. These proteins are thus candidate targets for spinal cord injury therapy. Our previous studies demonstrated that 810 nm photobiomodulation inhibited the formation of chondroitin sulfate proteoglycans after spinal cord injury and greatly improved motor function in model animals. However, the specific mechanism and potential targets involved remain to be clarified. In this study, to investigate the therapeutic effect of photobiomodulation, we established a mouse model of spinal cord injury by T9 clamping and irradiated the injury site at a power density of 50 mW/cm2 for 50 minutes once a day for 7 consecutive days. We found that photobiomodulation greatly restored motor function in mice and downregulated chondroitin sulfate proteoglycan expression in the injured spinal cord. Bioinformatics analysis revealed that photobiomodulation inhibited the expression of proteoglycan-related genes induced by spinal cord injury, and versican, a type of proteoglycan, was one of the most markedly changed molecules. Immunofluorescence staining showed that after spinal cord injury, versican was present in astrocytes in spinal cord tissue. The expression of versican in primary astrocytes cultured in vitro increased after inflammation induction, whereas photobiomodulation inhibited the expression of versican. Furthermore, we found that the increased levels of p-Smad3, p-P38 and p-Erk in inflammatory astrocytes were reduced after photobiomodulation treatment and after delivery of inhibitors including FR 180204, (E)-SIS3, and SB 202190. This suggests that Smad3/Sox9 and MAPK/Sox9 pathways may be involved in the effects of photobiomodulation. In summary, our findings show that photobiomodulation modulates the expression of chondroitin sulfate proteoglycans, and versican is one of the key target molecules of photobiomodulation. MAPK/Sox9 and Smad3/Sox9 pathways may play a role in the effects of photobiomodulation on chondroitin sulfate proteoglycan accumulation after spinal cord injury.

Immediate effects of photobiomodulation on saliva production.

To verify the immediate effects of photobiomodulation on the production of salivary flow and the correlation of demographic, anthropometric and medication use data. The study included 100 healthy individuals, aged between 18 and 76 years (mean 27.2 years), randomly split into an experimental group and a placebo group. Assessments of anthropometric measurements, self-perception of saliva production and sialometry were performed. Next, LASER irradiation was carried out at an infrared wavelength (808 nanometers) with 100 milliwatts (mw) of power at five intraoral points: on the sublingual glands and bilaterally on the submandibular and parotid glands, at doses of 9, 18 and 24 joules (J). Sialometry was repeated after each application. The control group received the same procedures with placebo equipment. There was a statistical association in the self-perception of reduced saliva in the experimental group for the 24J dose and in sialometry and in the reduction in salivary flow for the 18J and 24J doses and an increase to 9J, in both groups. There was no association when comparing the experimental and placebo groups. Multiple multinomial regression analysis revealed that the reduction or increase in salivary flow is independent of demographic, anthropometric and medication use variables. The bioinhibitory action of photobiomodulation on healthy salivary glands occurred at a dose of 18J and 24J, while the biostimulant action happened at a dose of 9J, regardless of demographic, anthropometric variables and medication use. The self-perception of reduced salivary flow occurred at 24J.

Efeitos imediatos da fotobiomodulação na produção de saliva

ABSTRACT Purpose To verify the immediate effects of photobiomodulation on the production of salivary flow and the correlation of demographic, anthropometric and medication use data. Methods The study included 100 healthy individuals, aged between 18 and 76 years (mean 27.2 years), randomly split into an experimental group and a placebo group. Assessments of anthropometric measurements, self-perception of saliva production and sialometry were performed. Next, LASER irradiation was carried out at an infrared wavelength (808 nanometers) with 100 milliwatts (mw) of power at five intraoral points: on the sublingual glands and bilaterally on the submandibular and parotid glands, at doses of 9, 18 and 24 joules (J). Sialometry was repeated after each application. The control group received the same procedures with placebo equipment. Results There was a statistical association in the self-perception of reduced saliva in the experimental group for the 24J dose and in sialometry and in the reduction in salivary flow for the 18J and 24J doses and an increase to 9J, in both groups. There was no association when comparing the experimental and placebo groups. Multiple multinomial regression analysis revealed that the reduction or increase in salivary flow is independent of demographic, anthropometric and medication use variables. Conclusion The bioinhibitory action of photobiomodulation on healthy salivary glands occurred at a dose of 18J and 24J, while the biostimulant action happened at a dose of 9J, regardless of demographic, anthropometric variables and medication use. The self-perception of reduced salivary flow occurred at 24J.