Low-level laser therapy (904nm) can increase collagen and reduce oxidative and nitrosative stress in diabetic wounded mouse skin

Nitric oxide-based treatments improve wound healing associated with diabetes mellitus

Non-healing wounds are long-term complications of diabetes mellitus (DM) that increase mortality risk and amputation-related disability and decrease the quality of life. Nitric oxide (NO·)-based treatments (i.e., use of both systemic and topical NO· donors, NO· precursors, and NO· inducers) have received more attention as complementary approaches in treatments of DM wounds. Here, we aimed to highlight the potential benefits of NO·-based treatments on DM wounds through a literature review of experimental and clinical evidence. Various topical NO·-based treatments have been used. In rodents, topical NO·-based therapy facilitates wound healing, manifested as an increased healing rate and a decreased half-closure time. The wound healing effect of NO·-based treatments is attributed to increasing local blood flow, angiogenesis induction, collagen synthesis and deposition, re-epithelization, anti-inflammatory and anti-oxidative properties, and potent broad-spectrum antibacterial effects. The existing literature lacks human clinical evidence on the safety and efficacy of NO·-based treatments for DM wounds. Translating experimental favors of NO·-based treatments of DM wounds into human clinical practice needs conducting clinical trials with well-predefined effect sizes, i.e., wound reduction area, rate of wound healing, and hospital length of stay.

The combined treatment of gold nanoparticles associated with photobiomodulation accelerate the healing of dermonecrotic lesion

Introduction: The search for fast and efficient treatment for dermonecrotic lesions caused by the venom of the spider from the Loxosceles simillis, is a demand in health. Prednisolone is one of the most used drugs, however it has side effects. In this context, addictionally gold nanoparticles (GNPs) have anti-inflammatory, antioxidant, and antibacterial properties. The use of photobiomodulation has show to be efficient in the process of tissue repair. Therefore, the purpose of this study was to investigate the anti-inflammatory effect of photobiomodulation and GNPs associated or not with a low concentration of prednisolone in animal models of dermonecrotic lesion.Methodology: For this, rabbits with venon-induced dermonecrotic lesion were subjected to topical treatment with prednisolone + laser or GNPs + laser or Pred-GNPs + laser. The area of edema, necrosis and erythema were measured. On the last day of treatment, the animals were euthanized to remove the organs for histopathological and biochemical analysis.Results: All treatments combinations were effective in promoting the reduction of necrotic tissue and erythema.Conclusion: With this results, we suggest that the use of laser and nanoparticles, associated or not with prednisolone, should be considered for the treatment of dermonecrotic injury.

On-demand Opto-Laser activatable nanoSilver ThermoGel for treatment of full-thickness diabetic wound in a mouse model

Patients suffering from diabetes mellitus are prone to develop diabetic wounds that are non-treatable with conventional therapies. Hence, there is an urgent need of hour to develop the therapy that will overcome the lacunas of conventional therapies. This investigation reports the Quality by Design-guided one-pot green synthesis of unique Opto-Laser activatable nanoSilver ThermoGel (OL→nSil-ThermoGel) for hyperthermia-assisted treatment of full-thickness diabetic wounds in mice models. The characterization findings confirmed the formation of spherical-shaped nanometric Opto-Laser activatable nanoSilver (30.75 ± 2.7 nm; ∆T: 37 ± 0.2 °C → 66.2 ± 0.1 °C; at 1.8 W/cm2 NIR laser density). The findings indicated acceptable in vitro cytocompatibility and significant keratinocyte migration (95.04 ± 0.07 %) activity of OL→nSil towards HaCaT cells. The rheological data of OL→nSil hybridized in situ thermoresponsive gel (OL→nSil-ThermoGel) showed the gelling temperature at 32 ± 2 °C. In vivo studies on full-thickness diabetic wounds in a Mouse model showed OL→nSil-ThermoGel accelerated wound closure (94.42 ± 1.03 %) and increased collagen synthesis, angiogenesis, and decreased inflammatory markers. Similarly, immunohistochemistry study showed significant angiogenesis and faster phenotypic switching of fibroblasts to myofibroblasts in OL→nSil-ThermoGel treated diabetic wounds. Histological evaluation revealed a marked rise in keratinocyte migration, organized collagen deposition, and early regeneration of the epithelial layer compared to the diabetic wound control. In conclusion, the OL→nSil-ThermoGel modulates the cytokines, re-epithelialization, protein expression, and growth factors, thereby improving the repair and regeneration of diabetic wounds in mice.

Tailoring photobiomodulation to enhance tissue regeneration

Photobiomodulation (PBM), the use of biocompatible tissue-penetrating light to interact with intracellular chromophores to modulate the fates of cells and tissues, has emerged as a promising non-invasive approach to enhancing tissue regeneration. Unlike photodynamic or photothermal therapies that require the use of photothermal agents or photosensitizers, PBM treatment does not need external agents. With its non-harmful nature, PBM has demonstrated efficacy in enhancing molecular secretions and cellular functions relevant to tissue regeneration. The utilization of low-level light from various sources in PBM targets cytochrome c oxidase, leading to increased synthesis of adenosine triphosphate, induction of growth factor secretion, activation of signaling pathways, and promotion of direct or indirect gene expression. When integrated with stem cell populations, bioactive molecules or nanoparticles, or biomaterial scaffolds, PBM proves effective in significantly improving tissue regeneration. This review consolidates findings from in vitro, in vivo, and human clinical outcomes of both PBM alone and PBM-combined therapies in tissue regeneration applications. It encompasses the background of PBM invention, optimization of PBM parameters (such as wavelength, irradiation, and exposure time), and understanding of the mechanisms for PBM to enhance tissue regeneration. The comprehensive exploration concludes with insights into future directions and perspectives for the tissue regeneration applications of PBM.

In-vitro study on type I collagen synthesis in low-level laser therapy on the early ligament fibroblasts' healing process

BACKGROUND

Low-level Laser Therapy (LLLT) has demonstrated its potential in promoting fiber matrix maturation, collagen synthesis, and fibroblast proliferation, contributing to tissue regeneration. Our study aimed to investigate the impact of LLLT on collagen type I synthesis, cell proliferation, and viability in human ligament fibroblasts derived from the Anterior Cruciate Ligament (ACL).

METHODS

Tissue samples were obtained from individuals undergoing arthroscopic ACL reconstruction surgery. Primary human fibroblasts were isolated, and immunohistochemical assays confirmed their characteristics. LLLT at 850 nm was administered in three groups: Low dose (1.0 J/cm²), High dose (5.0 J/cm²), and Control (0.0 J/cm²). Cell viability was calculated using a membrane integrity assay, proliferation was determined by automated counting, and collagen type I concentration in cell culture was measured using an immunoassay.

RESULTS

Fibroblasts showed decreased viability after low and high doses of LLLT, increased proliferation at the low dose, and increased collagen synthesis at the high dose on day 10 for both sexes after treatment.

CONCLUSION

Our study demonstrated that LLLT may improve the early ligament healing process by increasing cell proliferation at the low dose and enhancing collagen type I synthesis at the high dose in human ligament fibroblasts.

Effect of Using Photobiomodulation (660 Nanometers) for the Treatment of Diabetic Ulcers: Protocol for a Randomized Controlled Trial

Diabetic foot ulcers (DFUs) result in tissue damage or impairment of deeper structures that affect quality of life. The impacts are numerous, and even after a long treatment period, 65% of patients experience recurrence. Among the interventions used to accelerate the healing process of DFUs, photobiomodulation therapy (PBMT) is a painless, noninvasive, and low-cost treatment. To achieve effective therapeutic results optimal PBMT parameters are necessary. The positive effect of PBMT on diabetic cells may be dependent on fluence (J/cm2) and wavelength (nm). This double-blind, randomized clinical trial will be conducted at the University Clinic of Physical Therapy. One hundred patients will be randomly placed in 4 groups. A Laserpulse Ibramed (Helium-Neon, HeNe, 660 nm) with 20 W power will be used (continuous mode), with doses stipulated for each treatment group (GL1, 4 J/cm2; GL2, 8 J/cm2; GL3, 12 J/cm2) and Endophoton KLD GaAs 904 nm (ST, 10 J/cm2) for 2 nonconsecutive days per week for 10 weeks, for a total of 20 sessions. The primary outcomes will be ulcer healing rate and University of Texas classification scores. Patients' DFUs will be assessed on the 1st day, 5 weeks, and 10 weeks of treatment then 1 month after the end of treatment. This study may aid effective clinical decision-making for the management of DFUs.

Dose-response and efficacy of 904 nm photobiomodulation on diabetic foot ulcers healing: a randomized controlled trial

PURPOSE

This study aimed to examine the impact of a 904 nm photobiomodulation (PBM) on diabetic ulcers using varying dosages.

METHODS

The study was a randomized, double-blind, placebo-controlled clinical trial that compared treatments using PBM (GaAs 904 nm 30w) with three different energy densities (4 J/cm2; 8 J/cm2; 10 J/cm2) in the healing process of non-infected diabetic foot ulcers. Eighty volunteers (48.75% female; 58.5 ± 11.1 years) were randomized into three intervention groups treated with PBM and one control group (PBM placebo). Volunteers performed up 20 interventions with PBM, either placebo or actual, in conjunction with conventional therapy, which involved dressing the wound with Helianthus annuus vegetable oil. The primary variable was the ulcer size reduction rate.

RESULTS

GaAs 904 nm PBM yielded a clinically and significant ulcer size rate reduction of diabetic foot ulcers, independently of energy density range (p < 0.05). However, 10 J/cm² had 60% of completely healed ulcers and the highest proportion of patients reaching 50% of ulcer reduction rate after 5 weeks of treatment. In addition, only 10 J/cm² showed a significant difference between control group after a 10-week follow-up (p < 0.05).

CONCLUSION

GaAs 904 nm PBM was effective in treating diabetic foot ulcers in this study and a dosage of 10 J/cm², after a 10-week follow-up, proved to be the most effective compared to the other groups.

CLINICAL TRIAL REGISTRATION NUMBER

NCT04246814.

Long-Term Outcome of Photobiomodulation Therapy for Refractory Diabetic Wound After Secretory Carcinoma of the Parotid Gland Surgery: A Case Report

Objective: To evaluate the efficacy and safety of photobiomodulation therapy (PBMT) in the treatment of diabetic patients with refractory wound. Background: Refractory wound is one of the most challenging clinical complications of diabetes mellitus. Studies have shown that PBMT can promote wound healing in many ways. Methods: We reported a 55-year-old male patient with refractory diabetic wound after secretory carcinoma of the parotid gland surgery responding to 810 nm laser. Results: After PBMT, the refractory diabetic wound healed gradually without adverse events. During follow-up 5-years, the healed wound remained stable and showed no signs of recurrence. Conclusions: PBMT can be potentially considered as a therapeutic method in diabetic patients with refractory diabetic wound.

Shedding Light on Photobiomodulation Therapy for Age-Related Macular Degeneration: A Narrative Review

BACKGROUND

Photobiomodulation (PBM) relies on the pathophysiological mechanism whereby red to near-infrared light can target mitochondrial activity and promote ATP synthesis. Preclinical and clinical studies have shown promising results in treating intermediate age-related macular degeneration (AMD), since PBM can produce photochemical reactions in endogenous retinal chromophores. Currently, PBM is approved by the Food and Drug Administration and by the European Medicines Agency for the treatment of intermediate AMD. This narrative review aimed to evaluate the available evidence on the effectiveness and safety of PBM in treating intermediate AMD.

METHODS

A comprehensive search was conducted using the PubMed database, employing the keywords "photobiomodulation" and "age-related macular degeneration." All English-language studies published up to June 2023 were reviewed, and the search was expanded to include relevant references from selected articles. The included publications were analyzed for this review.

RESULTS

The available studies on PBM in AMD demonstrated promising but inconsistent results. PBM showed potential in improving best-corrected visual acuity (BCVA) and contrast sensitivity (CS) in patients with AMD. Some studies also suggested a reduction in AMD lesions, such as drusen volume. However, the long-term efficacy and optimal treatment parameters of PBM in AMD remained to be fully determined due to the limitations of the available studies. These included variations in irradiation techniques, wavelengths, exposure times, and treatment sessions, making it challenging to generalize the effectiveness of PBM. Furthermore, the lack of accurate classification of AMD phenotypes in the available studies hindered the understanding of which phenotypes could truly benefit from this treatment. Finally, the strength of evidence varied among studies, with limited sample sizes, unpublished results, and only three randomized sham-controlled trials.

CONCLUSIONS

Currently, the effectiveness of PBM in promoting drusen resorption or preventing progression to advanced forms of AMD, as observed in the cited studies, remains uncertain.

Bibliometric Analysis to Global Research Status Quo on Photobiomodulation

Background: Photobiomodulation (PBM) becomes a remedial technology with growing popularity. The primary goal of this article is to conduct a PBM literature review, providing an overall systematic understanding of current and future trends. Methods: A dataset was made with topic retrieval, concerning PBM research retrieved from the Web of Science Core Collection. We analyzed to forecast research frontiers in this field using the softwares: VOSviewer, CiteSpace, and Biblioshiny. Results: Four thousand five hundred thirty pieces of literature were retrieved from our database. Current trends were characterized by keywords of "light," "spinal cord injury," "skeletal muscle," and so on. Future trends were characterized probably by six cutting-edge terms: "wound healing," "pain," "oral mucositis," "Alzheimer's disease," "Parkinson's disease," and "orthodontics." Conclusions: This study finds that the inadequacy of in-depth reliable interpretation of current clinical data calls for molecular biological mechanisms together with well-designed, large-sample, multicenter clinical trials. The study of oral, wound, and neural-related mechanisms and the exploration of therapeutic effects may be the popular trend at present and in the next few years.

Nanomedicine-fortified cosmeceutical serums for the mitigation of psoriasis and acne

Cosmetics have a long history of use for regenerative and therapeutic purposes that are appealing to both genders. The untapped potential of nanotechnology in cosmeceuticals promises enhanced efficacy and addresses the issues associated with conventional cosmetics. In the field of cosmetics, the incorporation of nanomedicine using various nanocarriers such as vesicle and solid lipid nanoparticles significantly enhances product effectiveness and promotes satisfaction, especially in tackling prevalent skin diseases. Moreover, vesicle-fortified serum is known for high skin absorption with the capacity to incorporate and deliver various therapeutics. Additionally, nano-embedded serum-based cosmeceuticals hold promise for treating various skin disorders, including acne and psoriasis, heralding potential therapeutic advancements. This review explores diverse nanotechnology-based approaches for delivering cosmetics with maximum benefits.

Dose-response relationship of photobiomodulation therapy and oxidative stress markers in healing dynamics of diabetic neuropathic ulcers in Wistar rats

Purpose

Diabetic foot ulcers are reported to be the most expensive complications of diabetes, with high morbidity and mortality rates. If the necessary care is not provided for the wound to heal, the individual may end up amputating the affected feet. Photobiomodulation therapy is a promising non-pharmacological treatment option for wound healing. The objective of the present study is to establish a dose-response relationship between photobiomodulation therapy and oxidative stress markers in the healing dynamics of diabetic neuropathic ulcers in Wistar rats.

Methodology

Diabetic neuropathy was induced in 126 Albino Wistar rats. An excisional wound of an area of 2cm2 was made on the neuropathy-induced leg. Photobiomodulation therapy of dosages 4, 6, 8, 10, 12, and 15 J/cm2 of wavelengths 655 and 808 nm was irradiated. The control group animals were kept un-irradiated. The outcome measures were assessed during wound healing's inflammatory, proliferative and remodelling phases.

Results

In the experimental group, animals treated with photobiomodulation therapy at doses of 4, 6, and 8 J/cm2 showed better wound healing dynamics. Photobiomodulation therapy modulated the reactive oxygen species and antioxidant levels, thereby improving the oxidative status of the wound.

Conclusion

Photobiomodulation therapy of dosages 4, 6, and 8 J/cm2 is effective and is a promising adjuvant modality in treating diabetic neuropathic ulcers. There was a strong dose-response relationship in the experimental groups treated with 4, 6 and 8 J/ cm2.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01157-2.

The Role of Physical Therapies in Wound Healing and Assisted Scarring

Wound healing (WH) is a complex multistep process in which a failure could lead to a chronic wound (CW). CW is a major health problem and includes leg venous ulcers, diabetic foot ulcers, and pressure ulcers. CW is difficult to treat and affects vulnerable and pluripathological patients. On the other hand, excessive scarring leads to keloids and hypertrophic scars causing disfiguration and sometimes itchiness and pain. Treatment of WH includes the cleaning and careful handling of injured tissue, early treatment and prevention of infection, and promotion of healing. Treatment of underlying conditions and the use of special dressings promote healing. The patient at risk and risk areas should avoid injury as much as possible. This review aims to summarize the role of physical therapies as complementary treatments in WH and scarring. The article proposes a translational view, opening the opportunity to develop these therapies in an optimal way in clinical management, as many of them are emerging. The role of laser, photobiomodulation, photodynamic therapy, electrical stimulation, ultrasound therapy, and others are highlighted in a practical and comprehensive approach.

Effects of photobiomodulation on oxidative stress in rats with type 2 diabetes mellitus

The present study aimed to evaluate photobiomodulation effects on oxidative stress in type 2 diabetes mellitus (DM2). Thirty-one male Wistar rats were used and divided into 4 groups: group 1 - animals without diabetes mellitus 2 without laser 21 J/cm² (C-SHAM), group 2 - animals with diabetes mellitus 2 without laser 21 J/cm² (C-DM2), group 3 - animals without diabetes mellitus 2 with laser 21 J/cm² (L-SHAM), group 4 - animals with diabetes mellitus 2 with laser 21 J/cm² (L-DM2). The protocol was performed 5 days/week, for 6 weeks. The animals that received photobiomodulation had one dose irradiated at two spots in the right gastrocnemius muscle. Twenty-four hours after the last intervention, the animals were euthanized. Heart, diaphragm, liver, right gastrocnemius, plasma, kidneys, weighed, and stored for further analysis. In rats with DM2, photobiomodulation promoted a decrease in thiobarbituric acid reactive substance assay (TBARS) in plasma levels. On the other hand, photobiomodulation demonstrated an increase in non-protein thiol levels (NPSH) in the heart, diaphragm and gastrocnemius. Moreover, photobiomodulation produced in the heart, diaphragm and plasma levels led to an increase in superoxide dismutase (SOD). Interestingly, photobiomodulation was able to increase superoxide dismutase in rats without DM2 in the heart, diaphragm, gastrocnemius and kidneys. These findings suggested that 6 weeks of photobiomodulation in rats with DM2 promoted beneficial adaptations in oxidative stress, with a decrease in parameters of oxidant activity and an increase in antioxidant activity.

Invitro impact of a combination of red and infrared LEDs, infrared laser and magnetic field on biomarkers of oxidative stress and hemolysis of erythrocytes sampled from healthy individuals and diabetes patients

AIMS

Low-intensity infrared laser irradiation with output emissions of the laser and LED for in vitro irradiation of plasma and erythrocyte samples collected from healthy individuals and diabetes mellitus (DM) patients was used in the current study.

METHODS

The generated emission was in the range 0.85-0.89 nm with pulse duration near 130 ns and repetition rates of pulses 50, 150, 600, and 1500 Hz, average power 0, 50, or 100 mW, in the range of 1-9 min for different 30 variants of irradiation. The levels of 2-thiobarbituric-acid reactive substances (TBARS), aldehydic and ketonic derivatives of oxidatively modified proteins (OMP), total antioxidant capacity (TAC), acid-induced resistance of erythrocytes, and activities of the main antioxidant enzymes were assessed in erythrocyte and plasma samples after irradiation.

RESULTS

The low-intensity infrared laser irradiation and low-intensity light emitted by a red LED decreased the lipid peroxidation levels in the erythrocytes of both healthy individuals and DM patients. A statistically significant decrease in TBARS and OMP levels and an increase in the TAC level were observed at the irradiation energy of 34.39 and 68.79 J/cm² for samples collected from both healthy individuals and DM patients. The effects of the irradiation were accompanied by a statistically significant decrease in catalase activity of both healthy individuals and DM patients.

CONCLUSIONS

In many variants of the laser irradiation and low-intensity light emitted by a red LED used in our study, a decrease in the percent of hemolyzed erythrocytes was observed, suggesting that laser therapy protocols should take into account fluencies, frequencies, and wavelengths of the laser before the beginning of treatment, especially in DM patients.

Photobiomodulation promotes spinal cord injury repair by inhibiting macrophage polarization through lncRNA TUG1-miR-1192/TLR3 axis

BACKGROUND

Secondary spinal cord injury (SCI) often causes the aggravation of inflammatory reaction and nerve injury, which affects the recovery of motor function. Bone-marrow-derived macrophages (BMDMs) were recruited to the injured area after SCI, and the M1 polarization is the key process for inducing inflammatory response and neuronal apoptosis. We previously showed that photobiomodulation (PBM) can inhibit the polarization of M1 phenotype of BMDMs and reduce inflammation, but the underlying mechanisms are unclear. The purpose of this study is to explore the potential target and mechanism of PBM in treating SCI.

METHODS

Transcriptome sequencing and bioinformatics analysis showed that long noncoding RNA taurine upregulated gene 1 (lncRNA TUG1) was a potential target of PBM. The expression and specific mechanism of lncRNA TUG1 were detected by qPCR, immunofluorescence, flow cytometry, western blotting, fluorescence in situ hybridization, and luciferase assay. The Basso mouse scale (BMS) and gait analysis were used to evaluate the recovery of motor function in mice.

RESULTS

Results showed that lncRNA TUG1 may be a potential target of PBM, regulating the polarization of BMDMs, inflammatory response, and the axial growth of DRG. Mechanistically, TUG1 competed with TLR3 for binding to miR-1192 and attenuated the inhibitory effect of miR-1192 on TLR3. This effect protected TLR3 from degradation, enabling the high expression of TLR3, which promoted the activation of downstream NF-κB signal and the release of inflammatory cytokines. In vivo, PBM treatment could reduce the expression of TUG1, TLR3, and inflammatory cytokines and promoted nerve survival and motor function recovery in SCI mice.

CONCLUSIONS

Our study clarified that the lncRNA TUG1/miR-1192/TLR3 axis is an important pathway for PBM to inhibit M1 macrophage polarization and inflammation, which provides theoretical support for its clinical application in patients with SCI.

Experimental model of nephropathy associated with diabetes mellitus in mice

PURPOSE

Nontransmissible chronic diseases, such as diabetes mellitus (DM) and nephropathy, affect a significant portion of the population, often treated due to injuries that require healing and regeneration. To create an experimental model of associated comorbidities, for healing and regeneration studies, protocols for induction of nephropathy by ischemia and reperfusion (I/R) and induction of DM by injection of streptozotocin (STZ) were associated.

METHODS

Sixty-four mice (Mus musculus), female, adult, Swiss strain, weighing approximately 20 g, were divided into four groups: G1: control (n = 24), G2: nephropathy group (N) (n = 7), G3, DM (n = 9), and G4: N+DM (n = 24). Arteriovenous stenosis (I/R) of the left kidney was performed as the first protocol. The animals received a hyperlipidemic diet for 7 days after the injection of STZ (150 mg/kg, via i.p.) and an aqueous glucose solution (10%) for 24 h. The animals in the G3 and G4 groups were observed for 14 days before receiving the diet and STZ. The evolution of nephropathy was observed using a urine test strip and the DM, through the analysis of blood glucose with a reagent strip on a digital monitor.

RESULTS

The ischemic induction protocols of nephropathy and DM with STZ, associated, were sustainable, low-cost, and without deaths. There were alterations compatible with initial renal alterations, in the first 14 days, such as increased urinary density, pH alteration, presence of glucose, proteins and leukocytes, when compared to the control group. DM was confirmed by the presence of hyperglycemia 7 days after induction and its evolution after 14 days. The animals in the G4 group showed constant weight loss when compared to the other groups. It was possible to observe morphological alterations in the kidneys submitted to I/R, regarding coloration, during surgery and after the end of the observation period, in the volume and size of the left kidney, when compared to the contralateral kidney.

CONCLUSIONS

It was possible to induce nephropathy and DM associated in the same animal, in a simple way, confirmed with rapid tests, without losses, providing a basis for future studies.

The effect of photomodulation on fibroblast growth factor and the Ras/MAPK signalling pathway: a review

Objective:

Current therapies and technologies used to treat hard-to-heal diabetic wounds are limited to a 50% healing rate. The rise in the percentage of lower limb non-traumatic amputations in patients with diabetes has caused an increased demand for alternative, effective and safe treatment modalities. Photobiomodulation therapy (PBMT) utilises light to induce physiological changes and provide therapeutic benefits and has been shown to increase the healing of hard-to-heal wounds through the release of growth factors. The aim of this narrative review is to investigate the effect of photobiomodulation (PBM) on fibroblast growth factor (FGF) and the role of the Ras/MAPK signalling pathway in diabetic wound healing.

Method:

Relevant journal articles were obtained through PubMed and Google Scholar.

Results:

Experimental and clinical findings from the review show that PBM can stimulate the release of growth factors, including FGF, an essential cytokine in wound healing, and one which is present at lower concentrations in diabetic wounds. There is also activation of the Ras/MAPK signalling pathway.

Conclusion:

One mechanism through which healing may be stimulated by PBM is via the FGF-Ras/MAPK signalling pathway, although strong evidence under hyperglycaemic conditions is lacking.

Facial Aesthetic Laser-Assisted Protocol for the Management of Acne and Pigmentation: A Case Report

The demand for aesthetic procedures is significantly increasing worldwide. In this case report, an in-office laser-assisted protocol coupled with rejuvenating concentrate serum (Gluage, TEBISKIN Gluage, SkinMed, Italy) was made. A 24-year-old female patient presented with a chief complaint of abundant facial acne and localized pigmentation. Clinical examination revealed the presence of abundant acne on the forehead and cheeks and the presence of localized pigmentation. Laser-assisted protocol coupled with rejuvenating concentrate serum was suggested. The protocol consisted of a thorough cleansing of the face followed by irradiation with a 980 nm diode laser (Smart M, Lasotronix, Poland), followed by a 405 nm diode laser (Smart M, Lasotronix, Poland), the application of rejuvenating concentrate serum (Gluage, TEBISKIN Gluage, SkinMed, Italy), and irradiation with the 635 nm diode laser (Smart M, Lasotronix, Poland). The protocol was made once per week for three weeks (three sessions in total), and a three-month follow-up was made after the end of the last session to confirm the effectiveness of the treatment. Stomatology 1 diode laser (Smart M, Lasotronix, Poland) was used in this case report as a 980 nm, 405 nm, and 635 nm diode laser (Smart M, Lasotronix, Poland). During the follow-up period, an almost total reduction of the acne was observed with the total disappearance of the localized pigmentation. This case report confirms the effectiveness of the proposed laser-assisted facial aesthetic treatment. We invite further studies to be made within the same suggested promising protocol.

Photobiomodulation isolated or associated with adipose-derived stem cells allograft improves inflammatory and oxidative parameters in the delayed-healing wound in streptozotocin-induced diabetic rats

The single and associated impressions of photobiomodulation (PBM) and adipose-derived stem cells (ADS) on stereological parameters (SP), and gene expression (GE) of some antioxidant and oxidative stressors of repairing injured skin at inflammation and proliferation steps (days 4 and 8) of a delayed healing, ischemic, and infected wound model (DHIIWM) were examined in type one diabetic (DM1) rats. DM1 was induced by administration of streptozotocin (40 mg/kg) in 48 rats. The DHIIWM was infected by methicillin-resistant Staphylococcus aureus (MRSA). The study comprised 4 groups (each, n = 6): Group 1 was the control group (CG). Group 2 received allograft human (h) ADSs transplanted into the wound. In group 3, PBM (890 nm, 80 Hz, 0.2 J/cm²) was emitted, and in group 4, a combination of PBM+ADS was used. At both studied time points, PBM+ADS, PBM, and ADS significantly decreased inflammatory cell count (p < 0.05) and increased granulation tissue formation compared to CG (p < 0.05). Similarly, there were lower inflammatory cells, as well as higher granulation tissue in the PBM+ADS compared to those of alone PBM and ADS (all, p < 0.001). At both studied time points, the GE of catalase (CAT) and superoxide dismutase (SOD) was remarkably higher in all treatment groups than in CG (p < 0.05). Concomitantly, the outcomes of the PBM+ADS group were higher than the single effects of PBM and ADS (p < 0.05). On day 8, the GE of NADPH oxidase (NOX) 1 and NOX4 was substantially less in the PBM+ADS than in the other groups (p < 0.05). PBM+ADS, PBM, and ADS treatments significantly accelerated the inflammatory and proliferative stages of wound healing in a DIIWHM with MRSA in DM1 rats by decreasing the inflammatory response, and NOX1 and 4 as well; and also increasing granulation tissue formation and SOD and CAT. The associated treatment of PBM+ADS was more effective than the individual impacts of alone PBM and ADS because of the additive anti-inflammatory and proliferative effects of PBM plus ADS treatments.

Low-Level Laser Therapy in the Treatment of Autoimmune Thyroiditis

Introduction: Autoimmune thyroiditis (AIT) is an autoimmune disorder that is characterized by thyroid gland dysfunction. Low-level laser therapy (LLLT), as a safe and non-invasive intervention, has gained much attention in many clinical applications including pain relief, regenerative medicine, and autoimmune. Methods: In this review, we discuss the effect of LLLT on cellular responses and its application in the treatment of AIT. Such keywords as "low-level laser therapy", "photobiomodulation" and "autoimmune thyroiditis" were used to find studies related to laser therapy in AIT in Google Scholar, PubMed and Medline databases. Results: LLLT reduced thyroid gland inflammation and inhibited immune cell trafficking. LLLT modulated inflammatory responses and improved thyroid gland regeneration. Conclusion: Investigations indicated that besides current treatment strategies, LLLT could be a promising therapeutic approach for the treatment of AIT.

5G Electromagnetic Radiation Attenuates Skin Melanogenesis In Vitro by Suppressing ROS Generation

Recently, the impacts of 5G electromagnetic radiation (EMR) with 28 GHz on human health have been attracting public attention with the advent of 5G wireless communication. Here, we report that 5G (28 GHz) EMR can attenuate the skin pigmentation in murine melanoma cells (B16F10) and a 3D pigmented human epidermis model (Melanoderm™). B16 cells were exposed to 5G (28 GHz) with or without α-MSH for 4 h per day. Interestingly, 5G attenuated α-MSH-induced melanin synthesis. Fontana-Masson staining confirmed that the dendritic formation of α-MSH stimulated B16 cells was diminished by 5G exposure. To confirm the anti-melanogenic effect of 5G EMR, MelanoDerm™ was irradiated with 5G at a power intensity of 10 W/m² for 4 h a day for 16 days and melanin distribution was detected with Fontana-Masson staining, which supported the anti-melanogenic effect of 5G EMR. Consistently, 5G EMR suppressed α-MSH induced upregulation of melanogenic enzymes; tyrosinase, TRP-1, and TRP-2. Of note, 5G EMR attenuated ROS production stimulated by α-MSH and H₂O₂, suggesting that 5G EMR may dissipate ROS generation, which is pivotal for the melanin synthesis. Collectively, we demonstrated that 5G EMR can attenuate skin pigmentation by attenuating ROS generation.

Photobiomodulation Associated With Conservative Treatment for Achilles Tendon Rupture: A Double-Blind, Superiority, Randomized Controlled Trial

Objective

To investigate the effects of photobiomodulation on Achilles tendon rupture (ATR) treated conservatively.

Design

Prospective, patient- and assessor-blinded, parallel, randomized controlled trial.

Setting

Patients with acute ATR treated conservatively.

Participants

Thirty-four male individuals with acute unilateral ATR treated conservatively (N=34), equally divided in 2 groups: photobiomodulation group (PBMG) and sham group, with mean age of 45.5±9.47 and 48.7±8.38 years, respectively.

Intervention

All participants underwent through an immobilization period, followed by rehabilitation sessions (2 d/wk for 12 weeks) comprising strengthening, range of motion, and balance/weightbearing exercises. In PBMG, the tendon was irradiated with a photobiomodulation cluster (1 904 nm/50 mW infrared laser, 4 858 nm/50 mW infrared diodes, and 4 658 nm/40 mW red diodes; power density of 105 mW/cm² per cluster area) during the immobilization period (2 d/wk for 8 weeks) and the sham group received a simulation of the procedure with no irradiation. Outcomes were assessed at the removal of the immobilization 12 and 16 weeks after tendon rupture.

Main Outcome Measures

Primary outcome was the Achilles Tendon Rupture Score. Secondary outcomes included Numerical Pain Rating Scale at rest and during effort, plantar flexor strength, and ankle range of motion.

Results

Both groups demonstrated an increase in the Achilles Tendon Rupture Score and improvements in range of motion, plantar flexor strength, and pain. There were no significant differences in outcomes between the 2 groups (P>.05) except in pain during walking, which was significantly lower in the PBMG in week 12 (P<.01, effect size=0.56) and week 16 (P<.01, effect size=0.55).

Conclusion

Photobiomodulation associated with conservative treatment is not superior to conservative treatment alone for improving function in patients with acute ATR.

Investigation of the synergistic effect of platelet-rich plasma and polychromatic light on human dermal fibroblasts seeded chitosan/gelatin scaffolds for wound healing

Conventional wound healing treatments are insufficient for chronic wounds caused by factors such as senescence of fibroblasts, reduced growth factor synthesis, and poor angiogenesis. Recently, tissue engineering approaches have been investigated to develop effective therapies. In this study, a biochemical/biophysical stimulant-based 3D system was developed for the healing of chronic wounds. In this direction, genipin crosslinked chitosan (CHT)/gelatin (GEL) scaffolds were fabricated by freeze-drying and loaded with platelet-rich plasma (PRP). The scaffolds were seeded with human dermal fibroblasts and then, polychromatic light in near infrared region (NIR) was applied to the scaffolds for activating the platelets and stimulating the fibroblasts (photoactivation, PAC). Thus, fibroblasts were stimulated both chemically and physically by PRP and light, respectively. Cell migration, proliferation, morphology, gene expressions and reactive oxygen species (ROS) activity were evaluated in-vitro. Laminin and collagen 4 expressions that are important for extracellular matrix (ECM) formation, and PDGF (Platelet-derived growth factor) and VEGF (Vascular endothelial growth factor) expressions that are important for vascularization significantly increased in the presence of both PRP and light. Besides, PRP and light improved cell migration in 3D core-and shell model synergistically. Hydrogen peroxide content decreased in both PRP and light, indicating inhibition of ROS production. It was concluded that the stimulation of platelets with light in the NIR has a great potential to use for both platelets activation and stimulation of fibroblasts. As a result, an effective therapy can be developed for chronic wounds by using scaffold-based 3D systems together with PRP and photostimulation.

Photobiomodulation and photodynamic therapy applied after electrocauterization for skin healing optimization in rats

Photobiomodulation-PBM and Photodynamic Therapy-PDT have been used to induce healing. However, the effects of these therapies on skin-lesions induced by electrocautery are unknown, aiming at more favorable clinical and esthetic results. Electrocauterization was done in 78-female Wistar-rats using a system that includes an electrocautery and red-LED. The groups were: No injury, Injury, Injury + ALA (topical 5-aminolevulinic acid application), Injury + LED and Injury + ALA + LED (topical ALA application followed by photoactivation with LED). After 2nd, 7th and 14th days post-injury, immuno-histomorphometric analyses (inflammatory infiltrate, blood vessels, fibroblasts, eschar/epidermal thickness, IL-10 and VEGF) and biochemical assays of MPO (neutrophil), NAG (macrophage), nitrite, DCF (H₂ O₂ ), carbonyl (membrane's damage), sulfhydryl (membrane's integrity), SOD, GSH, hydroxyproline and re-epithelialization area were performed. The Injury + LED and Injury + ALA + LED groups controlled inflammation and oxidative stress, favoring angiogenesis, fibroblasts proliferation and collagen formation. Therefore, the PBM or PDT was effective in tissue formation with thinner eschar and epidermis, resulting in less scarring after electrocauterization.

Stimulatory responses in α- and β-cells by near-infrared (810 nm) photobiomodulation

Significant efforts have been committed to better understand and regulate insulin secretion as it has direct implications on diabetes. The first phase of biphasic insulin secretion in response to glucose lasts about 10 minutes, followed by a more sustained release persisting several hours. Attenuated insulin release in the first phase is typically associated with abnormal β-cells. While near-infrared photobiomodulation (PBM) demonstrates potential for multiple therapeutic applications, photostimulatory effects on α- and β-cells remain to be further elucidated. Herein, we demonstrate that 810 nm PBM exposure at fluence of 9 J/cm² can elevate the intracellular reactive oxygen species within 15 minutes following photostimulation. In addition, calcium spiking showed an approximately 3-fold increase in both ATC1 (α-cells) and BTC6 (β-cells) and correlates with hormone secretion in response to PBM stimulation. Our findings could lay a foundation for the development of non-biologic therapeutics that can augment islet transplantation.

Propranolol-loaded electrospun nanofibrous wound dressing: From fabrication and characterization to preliminary wound healing evaluation

OBJECTIVES

The wound healing potential of beta-blocker drugs such as propranolol (PNL) has recently attracted attention. To date, incorporation of PNL into electrospun nanofibrous wound dressing mats has not been tested as a novel topical drug delivery system. Presently, electrospun nanofibrous mats loaded with PNL were fabricated, and their physicochemical properties and wound healing activities were evaluated.

MATERIALS AND METHODS

Polyvinyl alcohol solutions containing 0, 2% or 4% (wt/vol) PNL were electrospun into mats, and the physicochemical properties and PNL release were evaluated. In vitro biocompatibility of selected PNL-loaded mats was tested in human foreskin fibroblasts and wound healing capability was evaluated in mouse skin wounds.

RESULTS

The 4% PNL mat had thin fibers (160 nm), convincing porosity (79.5%), and good hydrophilicity (swelling: 89.1%, water contact angle: 42.1°) with little degradability (14.2%). The release of PNL was not in bursts and was best explained by the Korsmeyer-Peppas equation (R2 = 0.96, n = 0.40), suggesting Fickian release. The viability of fibroblasts was 173% on day 5 of incubation with 4% PNL mats, indicating good mat biocompatibility. In vivo treatment for 14 days with 4% PNL mats resulted in wounds with a surface area of only 9% of the original wound area. These wounds had better histopathologic characteristics and were associated with less oxidative stress.

CONCLUSION

The wound dressing fabricated with 4% PNL showed good potential for wound healing because of a favorable drug release profile from the nanofiber scaffold, and can be considered eligible for further clinical research.

Effect of Photobiomodulation Therapy on Oxidative Stress Markers in Healing Dynamics of Diabetic Neuropathic Wounds in Wistar Rats

Background

Prolonged and overlapping phases of wound healing in diabetes are mainly due to the redox imbalance resulting in the chronicity of the wound. Photobiomodulation therapy works on the principle of absorption of photon energy and its transduction into a biological response in the living tissue. It alleviates the cellular responses, thereby improving the mechanism of wound healing in diabetes.

Objective

To find out the effect of photobiomodulation therapy of dosage 4 J/cm² in the healing dynamics of diabetic neuropathic wounds in Wistar rats and its relation with oxidative stress markers.

Methodology

Diabetes was induced using Streptozotocin of 60 mg/kg of body weight to eighteen female Wistar rats. Neuropathy was induced by the sciatic nerve crush injury followed by an excisional wound of 2 cm² on the back of the animal. Experimental group animals were treated with dosage 4 J/cm² of wavelength 655 and 808 nm, and control group animals were kept unirradiated. The biomechanical, histopathological, and biochemical changes were analysed in both groups.

Results

There was a reduction in mean wound healing time and an increased rate of wound contraction in the experimental group animals compared to its control group. The experimental group showed improved redox status, and histopathological findings revealed better proliferative cells, keratinisation, and epithelialization than un-irradiated controls.

Conclusions

Photobiomodulation therapy of dosage 4 J/cm² enhanced the overall wound healing dynamics of the diabetes-induced neuropathic wound and optimised the oxidative status of the wound, thereby facilitating a faster healing process.

Combination treatment of dendrosomal nanocurcumin and low-level laser therapy develops proliferation and migration of mouse embryonic fibroblasts and alter TGF-β, VEGF, TNF-α and IL-6 expressions involved in wound healing process

INTRODUCTION

Pressure ulcer (PU) is known as the third most costly disorder usually caused by prolonged pressure and stagnation in various parts of the body. Although several therapeutic approaches are employing, obstacles in appropriate healing for skin lesions still exist which necessitates new practical alternative or adjunctive treatments. Low level laser therapy (LLLT) as one of the mentioned new strategies have gained attention. Besides, curcumin is an herbal medicine extracted from turmeric with anti-inflammatory and antioxidative properties with promising beneficial therapeutic effects in wound healing. Employing dendrosomal nanoparticles, we overcome the hydrophobicity of curcumin in the present study. We hypothesized that combination treatment of DNC+LLLT (450 nm) simultaneously may promote the wound healing process.

MATERIAL AND METHODS

MTT assay, PI staining followed by flowcytometry, scratch assay and intracellular ROS measurement were used to investigate the effects caused by DNC and LLLT (450 nm) alone and in combination, on proliferation, cell cycle, migration and oxidative stress mouse embryonic fibroblast cells, respectively. The levels of growth factors and pro-inflammatory cytokines were evaluated by qRT-PCR and ELISA.

RESULTS

Our results indicated that combination exposure with DNC and LLLT leads to increased proliferation and migration of MEFs as well as being more efficient in significantly upregulating growth factors (TGF-β, VEGF) and decline in inflammatory cytokines (TNF-α, IL-6). Moreover, findings of this research provide persuasive support for the notion that DNC could reduce the LLLT-induced enhancement in intracellular ROS in mouse embryonic fibroblasts.

CONCLUSION

Concurrent exposure to anti-oxidant concentrations of DNC and LLLT enriched S phase entry and therefor increased proliferation as well as migration on MEFs through regulating the expression levels growth factors and shortening the inflammatory phase by modulating of cytokines. It should be noted that DNC were able to reduce the laser-induced oxidative stress, during wound healing, representing an informative accompaniment with LLLT.

Photobiomodulation in diabetic wound healing: A review of red and near-infrared wavelength applications

The development of a painless, non-invasive, and faster way to diabetic wound healing is at the forefront of research. The complexity associated with diabetic wounds makes it a cause for concern amongst diabetic patients and the world at large. Irradiation of cells generates a photobiomodulatory response on cells and tissues, directly causing alteration of cellular processes and inducing diabetic wound repair. Photobiomodulation therapy (PBMT) using red and near-infrared (NIR) wavelengths is being considered as a promising technique for speeding up the rate of diabetic wound healing, eradication of pain and reduction of inflammation through the alteration of diverse cellular and molecular processes. This review presents the extent to which the potential of red and NIR wavelengths have been harnessed in PBMT for diabetic wound healing. Important research challenges and gaps are identified and discussed, and future directions mapped out. This review thus provides useful insights and strategies into improvement of PBMT, including its acceptance within the global medical research community.

Effects of Buprenorphine, Chlorhexidine, and Low-level Laser Therapy on Wound Healing in Mice

Systemic buprenorphine and topical antiseptics such as chlorhexidine are frequently used in research animals to aid in pain control and to reduce infection, respectively. These therapeutics are controversial, especially when used in wound healing studies, due to conflicting data suggesting that they delay wound healing. Low-level laser therapy (LLLT) has been used to aid in wound healing without exerting the systemic effects of therapies such as buprenorphine. We conducted 2 studies to investigate the effects of these common treatment modalities on the rate of wound healing in mice. The first study used models of punch biopsy and dermal abrasion to assess whether buprenorphine HCl or 0.12% chlorhexidine delayed wound healing. The second study investigated the effects of sustained-released buprenorphine, 0.05% chlorhexidine, and LLLT on excisional wound healing. The rate of wound healing was assessed by obtaining photographs on days 0, 2, 4, 7, and 9 for the punch biopsy model in study 1, days 0, 1, 2, 4, 6, 8, 11, and 13 for the dermal abrasion model in study 1, and days 0, 3, 6, and 10 for the mice in study 2. Image J software was used to analyze the photographed wounds to determine the wound area. When comparing the wound area on the above days to the original wound area, no significant differences in healing were observed for any of the treatment groups at any time period for either study. Given the results of these studies, we believe that systemic buprenorphine, topical chlorhexidine, and LLLT can be used without impairing or delaying wound healing in mice.

Photobiomodulation: A review of the molecular evidence for low level light therapy

Light energy is harnessed for therapeutic use in a number of ways, most recently by way of photobiomodulation (PBM). This phenomenon is a cascade of physiological events induced by the nonthermal exposure of tissue to light at the near infrared end of the visible spectrum. Therapeutic PBM has become a highly commercialized interest, marketed for everything from facial rejuvenation to fat loss, and diode-based devices are popular in both the clinic setting and for use at home. The lack of regulatory standards makes it difficult to draw clear conclusions about efficacy and safety but it is crucial that we understand the theoretical basis for PBM, so that we can engage in an honest dialogue with our patients and design better clinical studies to put claims of efficacy to the test. This article presents a summary of the science of PBM and examines the differences between laser light, on which much of the preclinical evidence is based and light from diodes, which are typically used in a clinical setting.

Photobiomodulation: systematic review and meta-analysis of the most used parameters in the resolution diabetic foot ulcers

The most common photobiomodulation parameters used to aid in the treatment of diabetic foot ulcers were investigated in this paper. The databases MEDLINE, LILACS, MEDCARIB, PAHO-IRIS, and WHOLIS were searched with the following descriptors: diabetic foot ulcers AND low-level laser therapy OR low-level therapy AND wound healing; this search was conducted from January of 2014 to December of 2019. Inclusion criteria were randomized clinical trials on humans. Exclusion criteria were systematic reviews, literature reviews, studies with animals, studies lacking photobiomodulation parameters, and studies with non-diabetic individuals. The Jadad scale was used in order to analyze the methodological quality of the matching papers. There were seventeen studies found on PubMed and four on LILACS. Among these, seven were selected, according to the inclusion and exclusion criteria. Two out of the seven matching studies obtained a high score, and five obtained a low score, on the Jadad scale. The studies settled on the use of 600-nm and 800-nm wavelength spectrum. Most of the analyzed papers on photobiomodulation on diabetic foot ulcers did not describe the detailed parameters in their methodology. None of the studies featured the maximum score with regard to the Jadad scale for methodological quality. The relations of energy versus wavelength and power versus wavelength were divergent among the parameters on the papers. Therefore, it is necessary to analyze the parameters for an optimized power value in order to improve the results of the treatment.

Effect of Multiradiance Low-Level Laser Therapy and Topical Silver Sulfadiazine on Healing Characteristics of Dermal Wounds in Marine Toads (Rhinella marina)

Current recommendations for wound management in amphibians are based primarily on clinical experience and on extrapolation from other taxa, whereas controlled clinical studies are lacking. Low-level laser therapy, also termed photobiomodulation, has gained popularity in veterinary medicine and may represent a valuable adjunct therapy for wound care in amphibians, though dosing and safety evaluations have not been previously reported. Silver sulfadiazine (SSD), a topical antimicrobial, is commonly utilized in amphibian medicine but little is known about its effects on wound healing in this class of animals. This pilot study evaluated the effects of repeated treatments of low-level laser therapy or topical SSD on second-intention healing characteristics of surgically induced full-thickness dermal wounds in 33 adult wild-caught marine toads. Toads were anesthetized, and a 6 mm cutaneous biopsy was performed over the right dorsum. They were then randomly assigned to one of three groups: laser therapy (LT) at 5 Hz (905 nm wavelength on a super pulsed sequence), topical SSD (SD), or control sham treatment (CT). Treatments were administered at 24 hrs after biopsy and then every 72 hrs thereafter, concurrent with a visual assessment of the wound. Toads were euthanized at one of five timepoints (day 4, 7, 13, 19, or 28) to permit scoring of histologic criteria, including lymphocytic inflammation, granulomatous inflammation, heterophilic inflammation, granulation tissue, fibrosis, and reepithelialization. Visual assessments and histologic scoring did not identify a benefit of laser therapy or SSD as compared to controls. Laser therapy and SSD, at the doses and dosing schedule utilized in this pilot study, appear to be safe and well-tolerated treatments in marine toads, but may not be warranted for uncomplicated skin wounds in this species.

Improvement of full-thickness rat skin wounds by photobiomodulation therapy (PBMT): A dosimetric study

Basic dosimetric studies are necessary to support the use of photobiomodulation therapy (PBMT), since the great variety of laser parameters that are reported in the literature have created an obstacle to identifying reproducible results. Thus, the present study evaluates the process of tissue repair after the photobiomodulation therapy, taking into consideration the dose, frequency and the mode of energy delivery used. For this, 6 mm diameter wounds were created on dorsal skin of Wistar rats, and the animals were divided in control and irradiated groups, where L1 and L4 (irradiated with 1 point of 10 J/cm2), L2 and L5 (5 points of 10 J/cm2), L3 and L6 (1 point of 50 J/cm2), respectively for one or multiple days of irradiations. A diode laser, λ 660 nm, 40 mW of power and 0.028 cm2 of spot area was used. Our data showed that the group receiving multiple treatments over the first week post wounding, applied at 10 J/cm2 at each of 5 points on and around the wound (group L5) presented the best improvement of wound closure, higher cytokeratin 10, lower macrophage infiltration, and greater tissue resistance to rupture. We conclude that PBMT improves the skin wound healing process, and the outcomes were directly related to the chosen laser parameters and irradiation mode.

Role of 904 nm superpulsed laser-mediated photobiomodulation on nitroxidative stress and redox homeostasis in burn wound healing

BACKGROUND

Burn wound healing is delayed due to several critical factors such as sustained inflammation, vascular disorder, neuropathy, enhanced proteolysis, infection, and oxidative stress. Burn wounds have limited oxygen supply owing to compromised blood circulation. Hypoxic burn milieu leads to free radicals overproduction incurring oxidative injury, which impedes repair process causing damage to cell membranes, proteins, lipids, and DNA. Photobiomodulation (PBM) with 904 nm superpulsed laser had shown potent healing efficacy via attenuating inflammation while enhancing proliferation, angiogenesis, collagen accumulation, and bioenergetic activation in burn wounds.

METHODS

This study investigated the effects of 904 nm superpulsed laser at 0.4 mW/cm² average power density, 0.2 J/cm² total energy density, 100 Hz frequency, and 200 ns pulse width for 10 min daily for seven days postburn injury on nitroxidative stress, endogenous antioxidants status, and redox homeostasis.

RESULTS

Photobiomodulation treatment significantly decreased reactive oxygen species, nitric oxide, and lipid peroxidation levels as compared to non-irradiated control. Further, protective action of PBM against protein oxidative damage was evidenced by reduced protein carbonylation and advanced oxidation protein product levels along with significantly enhanced endogenous antioxidants levels of SOD, catalase, GPx, GST, reduced glutathione, and thiol (T-SH, Np-SH, P-SH). Biochemical changes aid in reduction of oxidative stress and maintenance of redox homeostasis, which further well corroborated by significantly up-regulated protein expression of Nrf 2, hemeoxygenase (HO-1), and thioredoxin reductase 2 (Txnrd2).

CONCLUSION

Photobiomodulation with 904 nm superpulsed laser led to reduction of nitroxidative stress, induction of endogenous antioxidants, and maintenance of redox homeostasis that could play a vital role in augmentation of burn wound healing.

The photobiomodulation (658, 830 and 904nm) on wound healing in histomorphometric analysis

Abstract Introduction: Photobiomodulation (PBM) assists in the processes of angiogenesis and cellular mitosis after skin lesion, contributing to tissue repair. Objective: to investigate the effects of photobiomodulation (during the proliferative phase) of 658 nm, 830 nm and 904 nm in the repair of skin lesions in an animal model. Method: 658 nm (G658), 830 nm (G830), 904 nm (G904) PBM, and control group (CG) integrated the research. We submitted the animals to an excisional wound and treatment at different wavelengths for 14 days. On the seventh and 14-1485004059th postoperative days, we calculated the area and percentage of lesion contraction. The animals were sacrificed on the 14-1485004056th postoperative day and cutaneous section of the injured region was collected for histomorphometric evaluation of the cellularity, neovascularization, thickness of the epidermis and volume density of collagen fibers colored with H&E and Picross Sirius respectively. For the statistical analysis, we applied the ANOVA test. Results: the G658 presented higher cellularity than GC (p = 0.03). The animals in the G658 group showed a significant increase in the neovascularization in relation to the CG (p = 0.01). Type III collagen significantly increased in G904 compared to G830 (p < 0.0001) and CG (p < 0.0001). The G658 had a significant increase in type III collagen fibers compared to G830 (p < 0.0001) and GC (p < 0.0001). We found no significant difference in the thickness of the epidermis, wound area, and in the percentage wound of contraction between the analyzed groups. Conclusion: PBM was effective to stimulate the tissue repair process, with better results for the 658 nm wavelength.

Healing Effects of Photobiomodulation on Diabetic Wounds

Diabetic patients frequently develop chronic ulcers of the lower extremities, which are a frequent cause for hospitalization and amputation, placing strain on patients, their families, and healthcare systems. Present therapies remain a challenge, with high recurrence rates. Photobiomodulation (PBM), which is the non-invasive application of light at specific wavelengths, has been shown to speed up healing of chronic wounds, including diabetic foot ulcers (DFUs). PBM produces photophysical and photochemical changes within cells without eliciting thermal damage. It has been shown to promote tissue regeneration and speed up wound repair by reducing inflammation and oxidative stress, accelerating cell migration and proliferation, and promoting extracellular matrix production and release of essential growth factors. The shortage of rigorous, well-designed clinical trials makes it challenging to assess the scientific impact of PBM on DFUs, and lack of understanding of the underlying mechanisms also hinders the conventional use of this therapy. This review gives a glimpse into diabetic wound healing and PBM, and the effects of PBM on diabetic wound healing.

Photobiomodulation Mitigates Cerebrovascular Leakage Induced by the Parkinsonian Neurotoxin MPTP

The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is commonly used to model Parkinson’s disease (PD) as it specifically damages the nigrostriatal dopaminergic pathway. Recent studies in mice have, however, provided evidence that MPTP also compromises the integrity of the brain’s vasculature. Photobiomodulation (PBM), the irradiation of tissue with low-intensity red light, mitigates MPTP-induced loss of dopaminergic neurons in the midbrain, but whether PBM also mitigates MPTP-induced damage to the cerebrovasculature has not been investigated. This study aimed to characterize the time course of cerebrovascular disruption following MPTP exposure and to determine whether PBM can mitigate this disruption. Young adult male C57BL/6 mice were injected with 80 mg/kg MPTP or isotonic saline and perfused with fluorescein isothiocyanate FITC-labelled albumin at various time points post-injection. By 7 days post-injection, there was substantial and significant leakage of FITC-labelled albumin into both the substantia nigra pars compacta (SNc; p < 0.0001) and the caudate-putamen complex (CPu; p ≤ 0.0003); this leakage partly subsided by 14 days post-injection. Mice that were injected with MPTP and treated with daily transcranial PBM (670 nm, 50 mW/cm², 3 min/day), commencing 24 h after MPTP injection, showed significantly less leakage of FITC-labelled albumin in both the SNc (p < 0.0001) and CPu (p = 0.0003) than sham-treated MPTP mice, with levels of leakage that were not significantly different from saline-injected controls. In summary, this study confirms that MPTP damages the brain’s vasculature, delineates the time course of leakage induced by MPTP out to 14 days post-injection, and provides the first direct evidence that PBM can mitigate this leakage. These findings provide new understanding of the use of the MPTP mouse model as an experimental tool and highlight the potential of PBM as a therapeutic tool for reducing vascular dysfunction in neurological conditions.

Assessment of Cytokine-Mediated Signaling Pathway Dysregulation in Arm Skin After CO2 Laser Therapy

Introduction: Laser therapy is known as an efficient approach in dermatology surgery. CO2 laser therapy is a gold standard treatment in skin surgery. This study aimed to evaluate the interferons change after CO2 laser surgery Methods: Significant differentially-expressed genes (DEGs) of arm skin after 7 days of treatment by the CO2 laser relative to the controls are downloaded from Gene Expression Omnibus (GEO) and are included in the protein-protein interaction network via a STRING database (an application of Cytoscape software). The central DEGs were identified and enriched via gene ontology by using Clue GO software. Results: A network including 78 DEGs and 100 neighbors was constructed and STAT1, MX1, ISG15, OAS1, IFIT1, IRF8, OASL, OAS2, and RSAD2 as hubs and STAT1, PTPRC, MX1, IRF8, ISG15, IL6, RORC, SAMSN1, and IFIT1 as bottlenecks were introduced. The cytokine-mediated signaling pathway, interferon gamma signaling, hepatitis C, interferon alpha/beta signaling, and the type I interferon signaling pathway were identified as 5 clusters of biological terms which are related to the central nodes. Conclusion: It can be concluded that the cytokine-mediated signaling pathway is the major pathway that is dysregulated after laser application in the treated skin.

Effects of Pulsed 810 nm Al-Ga-As Diode Laser on Wound Healing Under Immunosuppression: A Molecular Insight

BACKGROUND AND OBJECTIVES

Dysregulated inflammation is one of the major contributing factors for the prevalence of non-healing chronic wound in immunosuppressed subjects. Photobiomodulation (PBM) has emerged as a potential non-thermal, light-based therapeutic healing intervention for the treatment of impaired wounds.

STUDY DESIGN/MATERIALS AND METHODS

The present study delineates the underlying molecular mechanisms of PBM 810 nm laser-induced full-thickness cutaneous wound repair in immunosuppressed rats at continuous and pulsed wave-mode with power-density of 40 mW/cm ² , fluence 22.6 J/cm ² for 10 minutes daily for 7 post-wounding days. Molecular markers were assessed using biochemical, enzyme-linked immunosorbent assay quantification, enzyme kinetics and immunoblots analyses pertaining to inflammation, oxidative stress, cell survival, calcium signaling, and proliferation cascades.

RESULTS

Results distinctly revealed that pulsed 810 nm (10 Hz) PBM potentially influenced the cell survival and proliferation signaling pathway by significantly upregulated phospho-protein kinase B(phospho-Akt), phospho-extracellular-signal-regulated kinase 1 (ERK1), transient receptor potential vanilloid-3 (TRPV3), Ca²⁺ , calmodulin, transforming growth factor-β1 (TGF-β1), TGF-βR3, and Na ⁺ /K ⁺ -ATPase pump levels. PBM treatment resulted in reduction of exaggerated inflammatory responses evident by significantly repressed levels of interleukin-1β (IL-1β), IL-6, cyclooxygenase 2 (COX-2), and substance-P receptor (SPR), as well as inhibited apoptotic cell death by decreasing p53, cytochrome C, and caspase 3 levels (P < 0.05), which, in turn, effectively augment the wound repair in immunosuppressed rats. PBM treatment also lowered 4-hydroxynoneal (HNE) adduct level and NADP/NADPH ratio and upregulated the GRP78 expression, which might culminate into reduced oxidative stress and maintained the redox homeostasis.

CONCLUSIONS

Taken together, these findings would be helpful in better understanding of the molecular aspects involved in pulsed 810 nm laser-mediated dermal wound healing in immunosuppressed rats through regulation of cell survival and proliferation via Ca²⁺ -calmodulin, Akt, ERK, and redox signaling. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Wound Photobiomodulation Treatment Outcomes in Animal Models

The possibilities that photobiomodulation has brought on to the medical field are ever expanding and the scope it has reached is infinite. Determining how this relatively new treatment technique can be incorporated into the veterinary medical field is of interest to many medical professionals. In this review, we examine the treatment outcomes of low-level-laser therapy (LLLT) in different animal models to pinpoint any similarities between the studies. A search was conducted to identify LLLT studies using different animal models with an open or closed wound. The studies were compared to identify the laser parameters that resulted in positive treatment outcomes. The overall result of the studies examined indicated that daily laser exposure at a wavelength of a 600 or 800 nm range was the most beneficial across the rodent studies regardless of health status or wound type. More studies on rabbit, canine, and equine models are needed to explain the inconsistent results reviewed and find the correct treatment parameters for these species. Further research involving LLLT studies that focus on different factors including health status, treatment interval, wavelength, and energy density is needed to help validate our knowledge about the efficacy of using photobiomodulation in the veterinary medical field.

Low level laser therapy for the patients with painful diabetic peripheral neuropathy - A systematic review

BACKGROUND

Low Level Laser Therapy (LLLT) is an emerging treatment modality for management of neuropathic pain. It works by triggering biochemical changes with in cells.

OBJECTIVE

This systematic review focused on finding evidence on the effectiveness of LLLT on treatment of painful diabetic neuropathy.

METHODS

We conducted a systematic review (PubMed, Web of Science, CINAHL and Cochrane) to find the evidence on effectiveness of LLLT on treatment of painful diabetic neuropathy. Randomized and non-randomized studies were included in the review.

RESULTS

A total of 627 studies were screened. After the exclusion criteria (duplicate, animal studies, LLLT for treating other neuralgias) 6 studies were included in the study. The outcome measure that were considered were the difference in pain score and nerve conduction velocity test and quality of life questionnaire.

CONCLUSION

The evidence obtained shows LLLT has a positive effect in controlling diabetic neuropathic pain.

Laser Photobiomodulation in the acute inflammatory response of the calcaneal tendon injury in rats exposed to cigarette smoke

ABSTRACT Nicotine delays the healing process and increases the levels of myeloperoxidase (MPO), an enzyme that plays a key role in the production of reactive oxygen species during the inflammatory process. Laser Photobiomodulation (PBM) is one of the most used electrophysical agents in the treatment of the calcaneal tendon, however, its effects on MPO activity need to be further elucidated. This study aimed to evaluate the effects of laser PBM on MPO activity after inflicting an injury to the calcaneal tendon of rats exposed to cigarette smoke. Thirty-four male Wistar rats with 90 days of age were used. After 14 days of exposure to cigarette smoke, the animals were divided into three experimental groups: control group (CG, n=12), not submitted to injury or treatment; sham group (ShG, n=10), submitted to partial calcaneal tendon injury and laser PBM simulation; and laser PBM group (PBMG, n=12), submitted to partial calcaneal tendon lesion and treated with laser PBM within the first minute after injury. PBM decreased MPO activity levels in PBMG compared to ShG (CG: 1.38±0.69pg/ml; ShG: 3.78±1.09pg/ml; PBMG: 2.58±0.93pg/ml; p<0.005). In conclusion, applying laser PBM immediately after inflicting damage to the calcaneal tendon attenuates acute inflammatory activity in rats exposed to cigarette smoke.

Use of Exogenous and Endogenous Photomediators as Efficient ROS Modulation Tools: Results and Perspectives for Therapeutic Purposes

Reactive Oxygen Species (ROS) play an essential dual role in living systems. Healthy levels of ROS modulate several signaling pathways, but at the same time, when they exceed normal physiological amounts, they work in the opposite direction, playing pivotal functions in the pathophysiology of multiple severe medical conditions (i.e., cancer, diabetes, neurodegenerative and cardiovascular diseases, and aging). Therefore, the research for methods to detect their levels via light-sensitive fluorescent probes has been extensively studied over the years. However, this is not the only link between light and ROS. In fact, the modulation of ROS mediated by light has been exploited already for a long time. In this review, we report the state of the art, as well as recent developments, in the field of photostimulation of oxidative stress, from photobiomodulation (PBM) mediated by naturally expressed light-sensitive proteins to the most recent optogenetic approaches, and finally, we describe the main methods of exogenous stimulation, in particular highlighting the new insights based on optically driven ROS modulation mediated by polymeric materials.