Wound-healing effects of low-level laser therapy in diabetic rats involve the modulation of MMP-2 and MMP-9 and the redistribution of collagen types I and III

New Insights into Chemical Profiles and Health-Promoting Effects of Edible Mushroom Dictyophora indusiate (Vent ex. Pers.) Fischer: A Review

Mushrooms are valued for their culinary and medicinal benefits, containing bioactive compounds like polysaccharides, terpenoids, phenolics, lectins, and ergosterols. This review aims to encourage research on D. indusiata by summarizing its chemistry, health benefits, pharmacology, and potential therapeutic applications. Molecules from D. indusiata offer anti-diabetic, antioxidant, anti-tumor, hepatoprotective, and anti-bacterial effects. In particular, polysaccharides from Dictyophora indusiata (DIP) enhance immune function, reduce oxidative stress, and promote gut health as prebiotics. DIP shows neuroprotective effects by reducing oxidative damage, improving mitochondrial function, and regulating apoptosis, making them beneficial for neurodegenerative diseases. They also activate immune responses through TLR4 and NF-κB pathways. Additionally, compounds like dictyophorines and quinazoline from D. indusiata support nerve growth and protection. Mushrooms help regulate metabolism and improve lipid profiles, with potential applications in managing metabolic disorders, cancer, cardiovascular diseases, diabetes, and neurodegenerative conditions. Their wide range of bioactive compounds makes D. indusiata mushrooms functional foods with significant therapeutic potential.

Safflower Alleviates Pulmonary Arterial Hypertension by Inactivating NLRP3: A Combined Approach of Network Pharmacology and Experimental Verification

INTRODUCTION

Traditional Chinese medicinal plant, safflower, shows effective for treating pulmonary arterial hypertension (PAH), yet the underlying mechanisms remain largely unexplored. This study is aimed at exploring the potential molecular mechanisms of safflower in the treatment of PAH.

METHODS

Network pharmacology approach and molecular docking were applied to identify the core active compounds, therapeutic targets, and potential signaling pathways of safflower against PAH. Meanwhile, high-performance liquid chromatography (HPLC) assay was performed to determine the core compounds from safflower. Further, the mechanism of action of safflower on PAH was verified by in vivo and in vitro experiments.

RESULTS

A total of 15 active compounds and 177 targets were screened from safflower against PAH. Enrichment analysis indicated that these therapeutic targets were mainly involved in multiple key pathways, such as TNF signaling pathway and Th17 cell differentiation. Notably, molecular docking revealed that quercetin (core compound in safflower) displayed highest binding capacity with NLRP3. In vivo, safflower exerted therapeutic effects on PAH by inhibiting right ventricular hypertrophy, inflammatory factor release, and pulmonary vascular remodeling. Mechanistically, it significantly reduced the expression of proangiogenesis-related factors (MMP-2, MMP-9, Collagen 1, and Collagen 3) and NLRP3 inflammasome components (NLRP3, ASC, and Caspase-1) in PAH model. Similarly, these results were observed in vitro. Besides, we further confirmed that NLRP3 inhibitor had the same therapeutic effect as safflower in vitro.

CONCLUSION

Our findings suggest that safflower mitigates PAH primarily by inhibiting NLRP3 inflammasome activation. This provides novel insights into the potential use of safflower as an alternative therapeutic approach for PAH.

Modulation of gene expression in skin wound healing by photobiomodulation therapy: A systematic review in vivo studies

BACKGROUND

Wound healing is a multistep process involving coordinated responses of a variety of cell types, cytokines, growth factors, and extracellular matrix (ECM) components leading to the physiological restoration of tissue integrity. Photobiomodulation therapy (PBMT) has been highlighted as an approach to improve the healing process, nonetheless at the molecular level, the effects of PBMT are not entirely understood.

AIM

To systematically review publications that investigated gene expression after PBMT during in vivo skin repair.

METHODS

An electronic search was undertaken in Medline Ovid (Wolters Kluwer), PubMed (National Library of Medicine), Web of Science (Thomson Reuters), Scopus (Elsevier), Embase, and LILACS databases. The search strategy was conducted from the terms: low-level light therapy, gene expression, and wound healing and their synonyms. The databases were consulted in December 2023 and no publication year limit was used.

RESULTS

Eleven studies were included in this review and the expression of 186 genes was evaluated. PBMT modified the expression of several targets genes studied, such as down-regulation of genes related to extracellular matrix proteases (MMP2 and MMP9) and pro-inflammatory cytokines (IL10 and IL6) and up-regulation of DNMT3A and BFGF.

CONCLUSION

This review demonstrates that PBMT is capable of regulating gene expression during wound healing. Most evidence showed a positive impact of PBMT in regulating genes linked to inflammatory cytokines improving skin wound healing. Yet, the effects of PBMT in genes involved in other mechanisms still need to be better understood.

Deciphering the role of wound healing genes in skin cutaneous melanoma: Insights into expression, methylation, mutations, and therapeutic implications

Skin Cutaneous Melanoma (SKCM) is a form of cancer that originates in the pigment-producing cells, known as melanocytes, of the skin. Delay wound healing is often correlated with the occurrence of and progression of SKCM. In this comprehensive study, we investigated the intricate roles of two important wound healing genes in SKCM, including Matrix Metalloproteinase-2 (MMP2) and Matrix Metalloproteinase-9 (MMP9). Through a multi-faceted approach, we collected clinical samples, conducted molecular experiments, including RT-qPCR, bisulphite sequencing, cell culture, cell Counting Kit-8, colony formation, and wound healing assays. Beside this, we also used various other databases/tools/approaches for additional analysis including, UALCAN, GEPIA, HPA, MEXPRESS, cBioPortal, KM plotter, DrugBank, and molecular docking. Our results revealed a significant up-regulation of MMP2 and MMP9 in SKCM tissues compared to normal counterparts. Moreover, promoter methylation analysis suggested an epigenetic regulatory mechanism. Validations using TCGA datasets and immunohistochemistry emphasized the clinical relevance of MMP2 and MMP9 dysregulation. Functional assays demonstrated their synergistic impact on proliferation and migration in SKCM cells. Furthermore, we identified potential therapeutic candidates, Estradiol and Calcitriol, through drug prediction and molecular docking analyses. These compounds exhibited binding affinities, suggesting their potential as MMP2/MMP9 inhibitors. Overall, our study elucidates the diagnostic, prognostic, and therapeutic implications of MMP2 and MMP9 in SKCM, shedding light on their complex interplay in SKCM occurrence and progression.

Diabetes in spotlight: current knowledge and perspectives of photobiomodulation utilization

Introduction

Diabetes is a global health concern characterized by chronic hyperglycemia resulting from insulinopenia and/or insulin resistance. The rising prevalence of diabetes and its associated complications (ulcers, periodontitis, healing of bone defect, neuropathy, retinopathy, cardiopathy and nephropathy) necessitate innovative therapeutic approaches. Photobiomodulation (PBM), involves exposing tissues and cells to low-energy light radiation, leading to biological effects, largely via mitochondrial activation.

Methods

This review evaluates preclinical and clinical studies exploring the potential of PBM in diabetes and its complications, as well all clinical trials, both planned and completed, available on ClinicalTrials database.

Results

This review highlights the variability in PBM parameters across studies, hindering consensus on optimal protocols. Standardization of treatment parameters and rigorous clinical trials are needed to unlock PBM's full therapeutic potential. 87 clinical trials were identified that investigated PBM in diabetes mellitus (with 5,837 patients planned to be treated with PBM). Clinical trials assessing PBM effects on diabetic neuropathy revealed pain reduction and potential quality of life improvement. Studies focusing on wound healing indicated encouraging results, with PBM enhancing angiogenesis, fibroblast proliferation, and collagen density. PBM's impact on diabetic retinopathy remains inconclusive however, requiring further investigation. In glycemic control, PBM exhibits positive effects on metabolic parameters, including glucose tolerance and insulin resistance.

Conclusion

Clinical studies have reported PBM-induced reductions in fasting and postprandial glycemia without an increased hypoglycemic risk. This impact of PBM may be related to its effects on the beta cells and islets in the pancreas. Notwithstanding challenges, PBM emerges as a promising adjunctive therapy for managing diabetic neuropathy, wound healing, and glycemic control. Further investigation into its impact on diabetic retinopathy and muscle recovery is warranted.

Fabrication and Characterization of an Enzyme-Triggered, Therapeutic-Releasing Hydrogel Bandage Contact Lens Material

PURPOSE

The purpose of this study was to develop an enzyme-triggered, therapeutic-releasing bandage contact lens material using a unique gelatin methacrylate formulation (GelMA+).

METHODS

Two GelMA+ formulations, 20% w/v, and 30% w/v concentrations, were prepared through UV polymerization. The physical properties of the material, including porosity, tensile strain, and swelling ratio, were characterized. The enzymatic degradation of the material was assessed in the presence of matrix metalloproteinase-9 (MMP-9) at concentrations ranging from 0 to 300 µg/mL. Cell viability, cell growth, and cytotoxicity on the GelMA+ gels were evaluated using the AlamarBlueTM assay and the LIVE/DEADTM Viability/Cytotoxicity kit staining with immortalized human corneal epithelial cells over 5 days. For drug release analysis, the 30% w/v gels were loaded with 3 µg of bovine lactoferrin (BLF) as a model drug, and its release was examined over 5 days under various MMP-9 concentrations.

RESULTS

The 30% w/v GelMA+ demonstrated higher crosslinking density, increased tensile strength, smaller pore size, and lower swelling ratio (p < 0.05). In contrast, the 20% w/v GelMA+ degraded at a significantly faster rate (p < 0.001), reaching almost complete degradation within 48 h in the presence of 300 µg/mL of MMP-9. No signs of cytotoxic effects were observed in the live/dead staining assay for either concentration after 5 days. However, the 30% w/v GelMA+ exhibited significantly higher cell viability (p < 0.05). The 30% w/v GelMA+ demonstrated sustained release of the BLF over 5 days. The release rate of BLF increased significantly with higher concentrations of MMP-9 (p < 0.001), corresponding to the degradation rate of the gels.

DISCUSSION

The release of BLF from GelMA+ gels was driven by a combination of diffusion and degradation of the material by MMP-9 enzymes. This work demonstrated that a GelMA+-based material that releases a therapeutic agent can be triggered by enzymes found in the tear fluid.

Electromechanical therapy in diabetic foot ulcers patients: A systematic review and meta-analysis

Purpose

Diabetic foot ulcer (DFU) is one of the most devastating and troublesome consequences of diabetes. The current therapies are not always effective because of the complicated aetiology and interactions of local and systemic components in DFU. However, adjunctive therapy (electromechanical therapy) has become the latest modality in recent years, although there is a lack of significant research to support its utilization as a treatment standard. The purpose of this systematic research was to review the literature on the application of electromechanical therapies in the healing of DFUs.

Methods

For this systematic review, we searched PubMed, Medline, EmBase, the Cochrane library, and Google Scholar for the most current research (1990-2022) on electromechanical therapies for DFUs. We used the PICO method (where P is population, I is intervention, C is comparator/control, and O is outcome for our study) to establish research question with the terms [Electromechanical therapy OR Laser therapy OR photo therapy OR Ultrasound therapy OR Shockwave therapy] AND [diabetic foot ulcers OR diabetes] were used as search criteria. Searches were restricted to English language articles only. Whereas, Cochrane handbook of "Systematic Reviews of Interventions" with critical appraisal for medical and health sciences checklist for systematic review was used for risk of bias assessment. There were 39 publications in this study that were deemed to be acceptable. All the suitably selected studies include 1779 patients.

Results

The meta-analysis of 15 included research articles showed the overall effect was significant (P = 0.0002) thus supporting experimental groups have improvement in the DFUs healing in comparison to the control group.

Conclusion

This systematic review and meta-analysis revealed electromechanical treatments are significantly viable options for patients with DFUs. Electromechanical therapy can considerably reduce treatment ineffectiveness, accelerate healing, and minimize the time it takes for complete ulcer healing.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01240-2.

Nd:YAG-photobiomodulation enhanced ADSCs multilineage differentiation and immunomodulation potentials

To investigate the effects of Nd: YAG (1064 nm) photobiomodulation on multilineage differentiation and immunomodulation potentials of adipose tissue-derived stem cells (ADSCs) in vitro and in vivo. For in vitro experiments, cells were divided into the control group (non-irradiated control ADSCs) and photobiomodulation groups. 0.5 J/cm2, 1 J/cm2, 2 J/cm2, and 4 J/cm2 were used for proliferation assays; for ADSCs adipogenic differentiation assays, 0.5 J/cm2, 1 J/cm2 were applied; 1 J/cm2 was used for migration and immunomodulation assays. The differentiation abilities were assessed by qPCR, Oil Red O staining, and Alizarin Red staining. The immunomodulation potential was assessed by qPCR and human cytokine array. DSS-induced colitis model. was used to test the effect of photobiomodulation on ADSCs immunomodulation potentials in vivo. Nd:YAG-based photobiomodulation dose-dependently promoted ADSCs proliferation and migration; 1 J/cm2 showed the best promotion effect on proliferation. Moreover, Nd:YAG photobiomodulation promoted ADSCs osteogenic differentiation and brown adipose adipogenic differentiation. The potential immunomodulation assays showed Nd:YAG photobiomodulation improved Anti-inflammation capacity of ADSCs and photobiomodulation irradiated ADSCs effectively alleviated DSS-induced colitis severity in vivo. Our study suggests Nd:YAG photobiomodulation might enhance the ADSCs multilineage differentiation and immunomodulation potentials. These results might help to enhance ADSCs therapeutic effects for clinical application. However, further studies are needed to explore the mechanisms of Nd:YAG photobiomodulation promoting multilineage differentiation and immunomodulation potentials of ADSCs.

Snowflake-inspired and blink-driven flexible piezoelectric contact lenses for effective corneal injury repair

The cornea is a tissue susceptible to various injuries and traumas with a complicated cascade repair process, in which conserving its integrity and clarity is critical to restoring visual function. Enhancing the endogenous electric field is recognized as an effective method of accelerating corneal injury repair. However, current equipment limitations and implementation complexities hinder its widespread adoption. Here, we propose a snowflake-inspired, blink-driven flexible piezoelectric contact lens that can convert mechanical blink motions into a unidirectional pulsed electric field for direct application to moderate corneal injury repair. The device is validated on mouse and rabbit models with different relative corneal alkali burn ratios to modulate the microenvironment, alleviate stromal fibrosis, promote orderly epithelial arrangement and differentiation, and restore corneal clarity. Within an 8-day intervention, the corneal clarity of mice and rabbits improves by more than 50%, and the repair rate of mouse and rabbit corneas increases by over 52%. Mechanistically, the device intervention is advantageous in blocking growth factors' signaling pathways specifically involved in stromal fibrosis whilst preserving and harnessing the signaling pathways required for indispensable epithelial metabolism. This work put forward an efficient and orderly corneal therapeutic technology utilizing artificial endogenous-strengthened signals generated by spontaneous body activities.

Arnica montana L. associated with microcurrent accelerates the dermis reorganisation of skin lesions

The aim of this study was to test the effect of electrical stimulation in association with topical Arnica montana gel on organisational changes in the dermis during tissue repair. An experimental rat incisional skin lesion was used for the study. This involved making an incisional lesion on the dorsum of the animals using a scalpel. Ninety-six animals were used divided into the following groups: control (C), microcurrent (MC); topical treatment with Arnica montana gel (ARN); the ARN + microcurrent (ARN + MC). Treatments were administered daily, and injured tissue samples were collected and processed on Days 2, 6 and 10 for dermis analyses. Myeloperoxidase levels were greater in control than in treatment groups on Days 2 and 6. F4/80 expression was similar among all treatment groups and greater than that in control on Day 2. On Day 6, the expression of vascular endothelial growth factor was higher in the MC group than that in other groups, whereas transforming growth factor-β expression increased in the MC and ARN + MC groups on Day 10. The expression of matrix metalloproteinase-2 was higher in the ARN + MC group when compared with other groups on Day 10. Expression levels of collagen I were increased in the ARN and ARN + MC groups when compared with control and MC groups on Day 6, while expression of collagen III was enhanced in MC, ARN, and ARN + MC groups when compared with the control. The protocol combining microcurrent with topical application of ARN reduces the inflammatory process, increases myofibroblasts proliferation and decreases the presence of macrophages in the dermis during skin repair in rats.

Low-power laser in increasing doses improve wound healing process in rats

Low-power laser has been studied and applied as an auxiliary tool in wound healing. However, as it is a therapy with several variables to be controlled, there is great difficulty in establishing protocols and comparing its efficacy. Therefore, the objective of this study was to evaluate the effects of the use of low-power laser in fixed and crescent doses in the healing of skin wounds in rats. Seventy-five male Wistar rats were divided into three groups: G1 with animals that did not receive laser radiation; G2 with animals treated with fixed dose of 3 J/cm2 laser; G3 with animals treated with laser in increasing doses of 1 J/cm2, 3 J/cm2, 5 J/cm2. Macroscopic and histological analysis were performed. The lowest intensity of PMN was observed in the irradiated groups and G3 had lower intensity of this infiltrate compared to G1 and G2 (p <0.05). On the seventh day of injury, PMN infiltrate decreased in all groups, especially in G3 (p<0.05). It was observed that G2 had more blood vessels than G1 and G3 after 7 days of wound creation (p ˂ 0.05). Collagen quantification showed that laser-treated groups have increased collagen deposition. Different responses in the wound healing process were observed comparing G2 and G3 groups. The fluence of 1J/cm2 presented better results in the anti-inflammatory action than 3 J/cm2, although G3 presented the greatest amount of total collagen after ten days of treatment.

Silva-Filho E, Estevinho LM. Antibacterial and Healing Effect of Chicha Gum Hydrogel (Sterculia striata) with Nerolidol

Chicha gum is a natural polymer obtained from the Sterculia striata plant. The hydroxyl groups of its structure have a chemical affinity to form hydrogels, which favors the association with biologically active molecules, such as nerolidol. This association improves the biological properties and allows the material to be used in drug delivery systems. Chicha gum hydrogels associated with nerolidol were produced at two concentrations: 0.01 and 0.02 g mL-1. Then, the hydrogels were characterized by thermogravimetry (TG), Fourier Transform Infrared spectroscopy (FTIR), and rheological analysis. The antibacterial activity was tested against Staphylococcus aureus and Escherichia coli. The cytotoxicity was evaluated against Artemia salina. Finally, an in vivo healing assay was carried out. The infrared characterization indicated that interactions were formed during the gel reticulation. This implies the presence of nerolidol in the regions at 3100-3550 cm-1. The rheological properties changed with an increasing concentration of nerolidol, which resulted in less viscous materials. An antibacterial 83.6% growth inhibition effect was observed using the hydrogel with 0.02 g mL-1 nerolidol. The in vivo healing assay showed the practical activity of the hydrogels in the wound treatment, as the materials promoted efficient re-epithelialization. Therefore, it was concluded that the chicha hydrogels have the potential to be used as wound-healing products.

Bisphenol A modulates proliferation, apoptosis, and wound healing process of normal prostate cells: Involvement of G2/M-phase cell cycle arrest, MAPK signaling, and transcription factor-mediated MMP regulation

Bisphenol A (BPA) is commonly used to produce epoxy resins and polycarbonate plastics. BPA is an endocrine-disrupting chemical that is leaked from the polymer and absorbed into the body to disrupt the endocrine system. Although BPA may cause cytotoxicity in the prostate, a hormone-dependent reproductive organ, its underlying mechanism has not yet been elucidated. Here, we investigated the effects of BPA on cell proliferation, apoptosis, and the wound healing process using prostate epithelial cells (RWPE-1) and stromal cells (WPMY-1). Observations revealed that BPA induced G2/M cell cycle arrest in both cell types through the ATM-CHK1/CHK2-CDC25c-CDC2 signaling pathway, and the IC₅₀ values were estimated to be 150 μM. Furthermore, BPA was found to induce caspase-dependent apoptosis through initiator (caspase-8 and -9) and executioner (caspase-3 and -7) caspase cascades. In addition, BPA interfered with the wound healing process through inhibition of MMP-2 and - 9 expression, accompanied by reductions in the binding activities of AP-1 as well as NF-κB motifs. Phosphorylation of MAPKs was associated with the BPA-mediated toxicity of prostate cells. These results suggest that BPA exhibits prostate toxicity by inhibiting cell proliferation, inducing apoptosis, and interfering with the wound healing process. Our study provided new insights into the precise molecular mechanisms of BPA-induced toxicity in human prostate cells.

Dose-Response Relationship of Photobiomodulation Therapy on Matrix Metalloproteinase in Healing Dynamics of Diabetic Neuropathic Ulcers-An in vivo Study

Individuals with diabetic foot ulcers have overlapped the inflammatory, proliferative and remodeling phase, making the tissue vulnerable to delayed healing responses. We aimed to establish the dose-response relationship of photobiomodulation therapy of different doses and matrix metalloproteinases in the healing dynamics of diabetic neuropathic ulcers. Diabetes was induced in 126 Albino Wistar rats, and neuropathy was induced to the hind paw by a sciatic nerve injury method. An excisional wound was created on the neuropathy-induced leg. Photobiomodulation therapy of dosages 4, 6, 8, 10, 12 and 15 J cm^-2 and wavelength 655 nm and 808 nm was irradiated. Photobiomodulation therapy of dosages 4, 6 and 8 J cm^-2 showed better wound healing properties with optimized levels of matrix metalloproteinases-1 and 8. We observed a strong dose response in the experimental group treated with 6 and 8 J cm^-2 . The findings from the present study conclude that photobiomodulation therapy of dosages 4, 6 and 8 J cm^-2 is suggestive of usefulness in diabetic neuropathic ulcer healing. Markers like matrix metalloproteinases may give a clear direction on response to the therapy. Based on the findings from the present study, we recommend to validate the findings for safety and efficacy in future through human prospective randomized controlled clinical trials.

Targeting Interleukin-10 Restores Graft Microvascular Supply and Airway Epithelium in Rejecting Allografts

Interleukin-10 (IL-10) is a vital regulatory cytokine, which plays a constructive role in maintaining immune tolerance during an alloimmune inflammation. Our previous study highlighted that IL-10 mediated immunosuppression established the immune tolerance phase and thereby modulated both microvascular and epithelial integrity, which affected inflammation-associated graft malfunctioning and sub-epithelial fibrosis in rejecting allografts. Here, we further investigated the reparative effects of IL-10 on microvasculature and epithelium in a mouse model of airway transplantation. To investigate the IL-10 mediated microvascular and epithelial repair, we depleted and reconstituted IL-10, and monitored graft microvasculature, airway epithelium, and associated repair proteins. Our data demonstrated that both untreated control allografts and IL-10 (-) allografts showed a significant early (d6) increase in microvascular leakiness, drop-in tissue oxygenation, blood perfusion, and denuded airway epithelium, which is associated with loss of adhesion protein Fascin-1 and β-catenin on vascular endothelial cells at d10 post-transplantation. However, IL-10 (+) promotes early microvascular and airway epithelial repair, and a proportional increase in endothelial Fascin-1, and β-catenin at d10 post-transplantation. Moreover, airway epithelial cells also express a significantly higher expression of FOXJ1 and β-catenin in syngrafts and IL-10 (+) allografts as compared to IL-10 (-) and untreated controls at d10 post-transplantation. Collectively, these findings demonstrated that IL-10 mediated microvascular and epithelial changes are associated with the expression of FOXJ1, β-catenin, and Fascin-1 proteins on the airway epithelial and vascular endothelial cells, respectively. These findings establish a potential reparative modulation of IL-10 associated microvascular and epithelial repair, which could provide a vital therapeutic strategy to facilitate graft repair in clinical settings.

High Efficiency In Vitro Wound Healing of Dictyophora indusiata Extracts via Anti-Inflammatory and Collagen Stimulating (MMP-2 Inhibition) Mechanisms

Dictyophora indusiata or Phallus indusiatus is widely used as not only traditional medicine, functional foods, but also, skin care agents. Biological activities of the fruiting body from D. indusiata were widely reported, while the studies on the application of immature bamboo mushroom extracts were limited especially in the wound healing effect. Wound healing process composed of 4 stages including hemostasis, inflammation, proliferation, and remodelling. This study divided the egg stage of bamboo mushroom into 3 parts: peel and green mixture (PGW), core (CW), and whole mushroom (WW). Then, aqueous extracts were investigated for their nucleotide sequencing, biological compound contents, and wound healing effect. The anti-inflammatory determination via the levels of cytokine releasing from macrophages, and the collagen stimulation activity on fibroblasts by matrix metalloproteinase-2 (MMP-2) inhibitory activity were determined to serve for the wound healing process promotion in the stage 2–4 (wound inflammation, proliferation, and remodelling of the skin). All D. indusiata extracts showed good antioxidant potential, significantly anti-inflammatory activity in the decreasing of the nitric oxide (NO), interleukin-1 (IL-1), interleukin-1 (IL-6), and tumour necrosis factor-α (TNF-α) secretion from macrophage cells (p < 0.05), and the effective collagen stimulation via MMP-2 inhibition. In particular, CW extract containing high content of catechin (68.761 ± 0.010 mg/g extract) which could significantly suppress NO secretion (0.06 ± 0.02 µmol/L) better than the standard anti-inflammatory drug diclofenac (0.12 ± 0.02 µmol/L) and their MMP-2 inhibition (41.33 ± 9.44%) was comparable to L-ascorbic acid (50.65 ± 2.53%). These findings support that CW of D. indusiata could be an essential natural active ingredient for skin wound healing pharmaceutical products.

Topical application of metformin accelerates cutaneous wound healing in streptozotocin-induced diabetic rats

BACKGROUND

Diabetic chronic wound, which is one of the diabetic complications caused by hyperglycemia, characterized by prolonged inflammation has become one of the most serious challenges in the clinic. Hyperglycemia during diabetes not only causes prolonged inflammation and delayed wound healing but also modulates the activation of nuclear factor-kappa B (NF-κB) and the expression of matrix metalloproteinases (MMPs). Although metformin is the oldest oral antihyperglycemic drug commonly used for treating type 2 diabetes, few studies have explored the molecular mechanism of its topical effect on wound healing. Therefore, we aimed to investigate the molecular effects of topical metformin application on delayed wound healing, which's common in diabetes.

METHODS AND RESULTS

In this context, we created a full-thickness excisional wound model in Wistar albino rats and, investigated NF-κB p65 DNA-binding activity and expression levels of RELA (p65), MMP2 and MMP9 in wound samples taken on days 0, 3, 7, and 14 from diabetic/non-diabetic rats treated with metformin and saline. As a result of our study, we showed that topically applied metformin accelerates wound healing by suppressing NF-κB p65 activity and diminishing the expression of MMP2 and MMP9.

CONCLUSIONS

Diabetic wounds treated with metformin healed even faster than those in the control group that mimicked standard wound healing.

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.

Photobiomodulation invigorating collagen deposition, proliferating cell nuclear antigen and Ki67 expression during dermal wound repair in mice

The present investigation focuses on understanding the role of photobiomodulation in enhancing tissue proliferation. Circular excision wounds of diameter 1.5 cm were created on Swiss albino mice and treated immediately with 2 J/cm² and 10 J/cm² single exposures of the Helium-Neon laser along with sham-irradiated controls. During different days of healing progression (day 5, day 10, and day 15), the tissue samples upon euthanization of the animals were taken for assessing collagen deposition by Picrosirius red staining and cell proliferation (day 10) by proliferating cell nuclear antigen (PCNA) and Ki67. The positive influence of red light on collagen synthesis was found to be statistically significant on day 10 (P < 0.01) and day 15 (P < 0.05) post-wounding when compared to sham irradiation, as evident from the image analysis of collagen birefringence. Furthermore, a significant rise in PCNA (P < 0.01) and Ki67 (P < 0.05) expression was also recorded in animals exposed to 2 J/cm² when compared to sham irradiation and (P < 0.01) compared to the 10 J/cm² treated group as evidenced by the microscopy study. The findings of the current investigation have distinctly exhibited the assenting influence of red laser light on excisional wound healing in Swiss albino mice by augmenting cell proliferation and collagen deposition.

Effect of photobiomodulation therapy on the proliferation phase and wound healing in rats fed with an experimental hypoproteic diet

Photobiomodulation therapy (PBMT) has been indicated for enforcement on healing skin wounds. This study evaluated the effects of PBMT on the healing of skin wounds during the proliferation phase in rats with a hypoproteic diet. Rats were randomized to one of the following groups (n = 10 per group): (i) injured normoproteic (25% protein) not subjected to PBMT; (ii) injured normoproteic who received PBMT; (iii) injured hypoproteic (8% protein) not subjected to PBMT; and (iv) injured hypoproteic who received PBMT. Rats were submitted to skin wounds and then treated with PBMT (low-level laser therapy: 660 nm, 50 mW, 1.07 W/cm², 0.028 cm², 72 J/cm², 2 J). Analyses were performed at 7 and 14 days of follow-up: semi-quantitative histopathologic analysis, collagen type I and III expressions, immunohistochemical marking for matrix metalloproteinases-3 (MMP-3) and (matrix metalloproteinases-9) MMP-9, and mechanical resistance test. There were significant differences between the normoproteic groups and their respective treated groups (p < 0.05), as well as to treated and untreated hypoproteic groups in histopathologic analysis semi-quantitatively and immunohistochemistry for MMP-3 and 9, in which PBMT was able to decrease immunostaining. Moreover, there was a decrease in collagen deposition with the statistical difference (p < 0.05) for both collagen types III and I. In conclusion, PBMT application was proved effective in the treatment of cutaneous wounds in rats submitted to a hypoproteic diet. These alterations were more salient in the proliferation stage with the reduction of metalloproteinases providing better mechanical resistance of the injured area in the remodeling phase with an intensification of type I collagen.

Electromedical devices in wound healing management: a narrative review

Wound healing is the sum of physiological sequential steps, leading to skin restoration. However, in some conditions, such as diabetes, pressure ulcers (PU) and venous legs ulcers (VLU), healing is a major challenge and requires multiple strategies. In this context, some electromedical devices may accelerate and/or support wound healing, modulating the inflammatory, proliferation (granulation) and tissue-remodelling phases. This review describes some helpful electromedical devices including: ultrasonic-assisted wound debridement; electrotherapy; combined ultrasound and electric field stimulation; low-frequency pulsed electromagnetic fields; phototherapy (for example, laser therapy and light-emitting diode (LED) therapy); biophotonic therapies, and pressure therapies (for example, negative pressure wound therapy, and high pressure and intermittent pneumatic compression) The review focuses on the evidence-based medicine and adequate clinical trial design in relation to these devices.

Evaluation of angiogenesis, inflammation, and healing on irradiated skin graft with low-level laser therapy in rats (Rattus norvegicus albinus wistar)

The reconstructive techniques have been widely used in Veterinary Medicine. The post-operative adjuvants therapies like the low-level laser therapy (LLLT) are used to decrease inherent complications to reconstructive surgeries. This article purposed to define the LLLT effects on the healing, inflammation, and vascularization of the skin grafts in applicable time intervals to veterinary surgical routine. Forty rats (Rattus norvegicus albinus wistar) were used and each one was submitted to autogenous cutaneous mesh grafting in the interescapular region. The rats were randomly distributed in five groups (G1, G2, G3, G4, and G5) in accordance with the 6 J/cm² or 10 J/cm² dose every 3 or 5 days. These treatments were applied on the skin graft for 15 days. The histochemical evaluation with Picrosirius showed greater expression of collagen type 1 - red in grafts of G5 (p < 0.05), while in G1 did not; the expression of collagen type III - green was not induced by LLLT. The histochemical evaluation with hematoxylin-eosin showed greater numbers of fibroblasts in grafts of G4 (p < 0.05) and less hemorrhage in grafts of G5 (p < 0.05). There was modulation of the inflammatory response in irradiated skin grafts. It is concluded the exhibition of the skin grafts to 6 J/cm² or 10 J/cm² dose every 5 days improved the healing and the modulation of the local inflammation.

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.

Efficacy of Biophysical Energies on Healing of Diabetic Skin Wounds in Cell Studies and Animal Experimental Models: A Systematic Review

We have systematically assessed published cell studies and animal experimental reports on the efficacy of selected biophysical energies (BPEs) in the treatment of diabetic foot ulcers. These BPEs include electrical stimulation (ES), pulsed electromagnetic field (PEMF), extracorporeal shockwave (ECSW), photo energies and ultrasound (US). Databases searched included CINAHL, MEDLINE and PubMed from 1966 to 2018. Studies reviewed include animal and cell studies on treatment with BPEs compared with sham, control or other BPEs. Information regarding the objective measures of tissue healing and data was extracted. Eighty-two studies were eventually selected for the critical appraisal: five on PEMF, four each on ES and ECSW, sixty-six for photo energies, and three about US. Based on the percentage of original wound size affected by the BPEs, both PEMF and low-level laser therapy (LLL) demonstrated a significant clinical benefit compared to the control or sham treatment, whereas the effect of US did not reveal a significance. Our results indicate potential benefits of selected BPEs in diabetic wound management. However, due to the heterogeneity of the current clinical trials, comprehensive studies using well-designed trials are warranted to confirm the results.

Efficacy of low-level light therapy for treatment of diabetic foot ulcer: A systematic review and meta-analysis of randomized controlled trials

AIMS

The goal of this systematic review and meta-analysis based on seven Randomized control trials (RCTs) is to examine whether Low-level light therapy (LLLT) is effective at healing diabetic foot ulcer (DFU) and to provide evidence-based recommendations and clinical guidelines for the future clinical treatment of DFUs.

METHODS

Medline, Embase, Scopus, Cochrane Library, and Web of Science databases were searched for studies published up to June 30, 2017, without language or data restrictions. RCTs that investigated the use of LLLT for DFU treatment were included. Standard methods of meta-analysis were performed to evaluate outcomes of LLLT on the healing of DFU.

RESULTS

Seven RCTs involving 194 participants were eligible for this systematic review and meta-analysis. The results of meta-analysis showed that LLLT has emerged as a potential noninvasive treatment for DFUs, as LLLT was found to effectively reduce the ulcer area [weighted mean difference (WMD) 34.18, 95% confidence intervals (CI) 19.38-48.99, P < 0.00001], improve the complete healing rate [odds ratio (OR) 6.72, 95% CI 1.99-22.64, P = 0.002]. Qualitative analysis of the included RCTs found that LLLT also played a role in the treatment of DFUs through promoting rapid granulation formation and shortening ulcer closure time, as well as alleviating foot ulcer pain. None of the treatment-related adverse event was reported.

CONCLUSIONS

LLLT was recognized as a potential method in the comprehensive treatment of DFUs. Further well designed and high-quality studies are required to confirm the role of LLLT in the management of DFUs.

Effect of photobiomodulation therapy on oxidative stress markers of gastrocnemius muscle of diabetic rats subjected to high-intensity exercise

This study aimed to determine whether photobiomodulation therapy (PBMT) in diabetic rats subjected to high-intensity exercise interferes with the expression of the oxidative stress marker in the gastrocnemius muscle. Twenty-four male Wistar rats were included in this study comprising 16 diabetic and eight control rats. The animals were allocated into three groups-control, diabetic fatigue, and diabetic PBMT fatigue groups. Diabetes was induced via the intraperitoneal administration of streptozotocin (50 mg/kg). We subsequently assessed blood lactate levels and PBMT. The animals of the diabetic fatigue group PBMT were irradiated before the beginning of the exercises, with dose of 4 J and 808 nm, were submitted to treadmill running with speed and gradual slope until exhaustion, as observed by the maximum volume of oxygen and lactate level. The animals were euthanized and muscle tissue was removed for analysis of SOD markers, including catalase (CAT), glutathione peroxidase (GPx), and 2-thiobarbituric acid (TBARS) reactive substances. CAT, SOD, and GPx activities were significantly higher in the diabetic PBMT fatigue group (p < 0.05) than in the diabetic fatigue group. Outcomes for the diabetic PBMT fatigue group were similar to those of the control group (p > 0.05), while their antioxidant enzymes were significantly higher than those of the diabetic fatigue group. PBMT mitigated the TBARS concentration (p > 0.05). PBMT may reduce oxidative stress and be an alternative method of maintaining physical fitness when subjects are unable to perform exercise. However, this finding requires further testing in clinical studies.

Effect of pulsed high intensity laser therapy on delayed caesarean section healing in diabetic women

[Purpose] The objective of this study was to determine the effect of pulsed high intensity laser therapy on delayed caesarean section healing in diabetic women. [Subjects and Methods] This study was conducted on forty diabetic women with delayed caesarean wound healing, ranging in age from 28 to 38 years. They were randomly assigned into two groups; the group I (n=20) received pulsed high intensity laser therapy for 6-weeks, 3 times per week plus standard medical treatment for treatment of diabetes and caesarean wound patients, the group II (n=20) received sham laser treatment for 6 weeks, 3 times per week plus standard medical treatment for treatment of diabetes and caesarean wound patients. The wound size and appearance in all participants were measured by the tracing method and pressure sore status tool before and after the 6-week treatment. [Results] Pulsed high intensity laser therapy produced a significant difference in wound size and appearance in comparison to the sham laser treatment in diabetic women with delayed caesarean wound healing. [Conclusion] Pulsed high intensity laser therapy is effective in the treatment of delayed caesarean section healing in diabetic women.

Photobiomodulation alters matrix protein activity in stressed fibroblast cells in vitro

A balance is maintained between matrix synthesis and degradation, and a prolonged increase in matrix metalloproteinases (MMPs) affects healing. Photobiomodulation (PBM) speeds up healing and alters wound environment. The study aimed to determine changes in protein and gene expression of collagen type 1 (Col-I), MMP-3 and -9 and TIMP-1 in fibroblasts irradiated at 660 or 830 nm. Commercially purchased human skin fibroblast cells were modeled into five groups namely, normal, normal wounded, diabetic wounded, hypoxic wounded and diabetic hypoxic wounded. Control cells were sham irradiated. Laser irradiation was conducted at 660 or 830 nm (108/or 94 mW, 9.1 cm² , 420/or 483 s) with 5 J/cm² . Forty-eight hours post-irradiation, protein expression of TIMP-1, MMP-3, -9 and Col-I was determined by flow cytometry and immunofluorescence, and gene expression by real-time RT-PCR. There was an increase in TIMP-1 and Col-I, and a decrease in MMP-3 and -9, as well as an alteration in mRNA expression of MMP3, MMP9, TIMP1 and COL1A1 in irradiated cells. Due to the responsiveness of the diabetic hypoxic wounded model, the findings propose this model as appropriate for wound healing studies and suggest that PBM promotes the remodeling phase of wound healing by decreasing matrix degradation and upregulating synthesis.

670nm light treatment following retinal injury modulates Müller cell gliosis: Evidence from in vivo and in vitro stress models

Photobiomodulation (PBM) with 670 nm light has been shown to accelerate wound healing in soft tissue injuries, and also to protect neuronal tissues. However, little data exist on its effects on the non-neuronal components of the retina, such as Müller cells (MCs), which are the principal macroglia of the retina that play a role in maintaining retinal homeostasis. The aim of this study was to explore the effects of 670 nm light on activated MCs using in vivo and in vitro stress models. Adult Sprague-Dawley rats were exposed to photo-oxidative damage (PD) for 24 h and treated with 670 nm light at 0, 3 and 14 days after PD. Tissue was collected at 30 days post-PD for analysis. Using the in vitro scratch model with a human MC line (MIO-M1), area coverage and cellular stress were analysed following treatment with 670 nm light. We showed that early treatment with 670 nm light after PD reduced MC activation, lowering the retinal expression of GFAP and FGF-2. 670 nm light treatment mitigated the production of MC-related pro-inflammatory cytokines (including IL-1β), and reduced microglia/macrophage (MG/MΦ) recruitment into the outer retina following PD. This subsequently decreased photoreceptor loss, slowing the progression of retinal degeneration. In vitro, we showed that 670 nm light directly modulated MC activation, reducing rates of area coverage by suppressing cellular proliferation and spreading. This study indicates that 670 nm light treatment post-injury may have therapeutic benefit when administered shortly after retinal damage, and could be useful for retinal degenerations where MC gliosis is a feature of disease progression.

Low-level laser therapy in the management of plantar fasciitis: a randomized controlled trial

This study aimed at estimating the extent to which a combination therapy of low-level laser therapy (LLLT) with exercise and orthotic support (usual care) affects functional ability in the patient with plantar fasciitis (PF) when compared to usual care alone. Participants with PF were randomly allocated into two groups: LLLT (n = 27) and control (n = 22). All the participants received home exercise program with orthotic support. In addition, the LLLT group received a gallium-aluminum-arsenide laser with a 850-nm wavelength for ten sessions, three times a week. Functional outcomes were measured by function subscale of American Orthopedic Foot and Ankle Society Score (AOFAS-F) and 12-min walking test including walking speed, cadence, and activity-related pain using visual analog scale (VAS).The scores were recorded at baseline, third week, and third month after the treatment. Analysis was performed using repeated measures ANOVA and an intention to treat approach using multiple imputations. There was a significant improvement in AOFAS-F total score at 3 weeks in both groups (LLLT, p < 0.001; control, p = 0.002), but the improvements were seen only for the LLLT group for AOFAS-F total score (p = 0.04) and two individual items of AOFAS-F (walking distance (p < 0.001) and walking surface (p = 0.01)) at 3 months. The groups were comparable with each other for both walking speed and cadence at all assessment times (p > 0.05). Both groups showed significant reduction in pain over 3 months (LLLT, p < 0.001; control, p = 0.01); however, the LLLT group had lower pain than the control group at 3 months (p = 0.03). The combination therapy of LLLT with usual care is more effective to improve functional outcomes and activity-related pain when compared to usual care alone.

Effects of photobiomodulation therapy and topical non-steroidal anti-inflammatory drug on skeletal muscle injury induced by contusion in rats-part 2: biochemical aspects

Muscle injuries trigger an inflammatory process, releasing important biochemical markers for tissue regeneration. The use of non-steroidal anti-inflammatory drugs (NSAIDs) is the treatment of choice to promote pain relief due to muscle injury. NSAIDs exhibit several adverse effects and their efficacy is questionable. Photobiomodulation therapy (PBMT) has been demonstrated to effectively modulate inflammation induced from musculoskeletal disorders and may be used as an alternative to NSAIDs. Here, we assessed and compared the effects of different doses of PBMT and topical NSAIDs on biochemical parameters during an acute inflammatory process triggered by a controlled model of contusion-induced musculoskeletal injury in rats. Muscle injury was induced by trauma to the anterior tibial muscle of rats. After 1 h, rats were treated with PBMT (830 nm, continuous mode, 100 mW of power, 35.71 W/cm²; 1, 3, and 9 J; 10, 30, and 90 s) or diclofenac sodium (1 g). Our results demonstrated that PBMT, 1 J (35.7 J/cm²), 3 J (107.1 J/cm²), and 9 J (321.4 J/cm²) reduced the expression of tumor necrosis factor alpha (TNF-α) and cyclooxygenase-2 (COX-2) genes at all assessed times as compared to the injury and diclofenac groups (p < 0.05). The diclofenac group showed reduced levels of COX-2 only in relation to the injury group (p < 0.05). COX-2 protein expression remained unchanged with all therapies except with PBMT at a 3-J dose at 12 h (p < 0.05 compared to the injury group). In addition, PBMT (1, 3, and 9 J) effectively reduced levels of cytokines TNF-α, interleukin (IL)-1β, and IL-6 at all assessed times as compared to the injury and diclofenac groups (p < 0.05). Thus, PBMT at a 3-J dose was more effective than other doses of PBMT and topical NSAIDs in the modulation of the inflammatory process caused by muscle contusion injuries.

Photobiomodulation therapy action in wound repair skin induced in aged rats old: time course of biomarkers inflammatory and repair

Previous studies have discussed an inverse correlation between age and wound healing, because it relates to the association of aging with a gradual decrease in healing capacity. Treatment with photobiomodulation therapy (PBMT) improves wound healing by inducing increases in mitotic activity, numbers of fibroblasts, collagen synthesis, and neovascularization. Therefore, this study aimed to evaluate the effects of PBMT in cutaneous wound healing in aged rats. A punch biopsy of 8 mm in diameter was performed to produce a skin wound. The study included 45 male rats, of which 15 were young (30 days) and 30 were elderly (500 days). The 45 animals were distributed into 3 experimental groups, which were subjected to skin wounds and 1 aged group received PBMT, with a 30-mW laser beam (power density of 1.07 W/cm²), beam area of 0.028 cm², and λ660 nm produced through active phosphide Gallium-Aluminum-Indio (InGaAIP). The PBMT application took the form of a single-point transcutaneous method, with a total energy of 2 joules per wound site, energy density of 72 J/cm², and time of 1 min and 7 s. Analysis was performed to verify the effect of PBMT on the quantity of collagen I and III, metalloproteinase 3 and 9 (MMP-3 and MMP-9), tissue inhibitor of metalloproteinase-2 (TIMP-2) and of vascular endothelial growth factor (VEGF) at the wound site by immunohistochemistry, cytokine-induced neutrophil chemoattractant (CINC)-1, by enzyme-linked immunosorbent assay (ELISA) and interleukin (IL)-6 real-time polymerase chain reaction (RT-PCR). That we conclude LLLT is effective in the modulation of inflammatory mediators IL-6, CINC-1, VEGF, MMP-3, MMP-9 and TIMP-2 as well as increased collagen production in aged animals during different phases of the tissue regeneration process. However, the effects of PBMT obtained in the aged animals (aged LLLT group) suggest that new dosimetries should be tested to achieve better results.

Effect of low-level laser therapy on angiogenesis and matrix metalloproteinase-2 immunoexpression in wound repair

Low-level laser therapy (LLLT) induces anti-inflammatory and angiogenic activities in wound healing. However, the mechanism of action and optimal parameters require further clarification. In this study, we investigated the effects of LLLT on wound healing matrix metalloproteinase (MMP)-2 immunoexpression and angiogenic processes. Twenty female Wistar rats were randomly divided into four groups (n = 5) according to the treatments as follows. CG7 and CG14 were control groups at days 7 and 14, respectively, which received physiological saline (0.9 % NaCl daily). LG7 and LG14 were laser therapy groups at days 7 and 14, respectively, which received two (LG7) or four (LG14) LLLT applications (40 mW; 660 nm; 4 J/cm²). A dorsal skin sample in the wound area (measuring 2 cm²) was removed after the experimental period, and then the animals were euthanized. The specimens were processed for qualitative and quantitative histological analyses and measurement of MMP-2 expression in the dermis and epidermis. A persistent crust and moderate number of inflammatory cells were found in CG7 and CG14 groups. In the LG14 group, wounds demonstrated complete re-epithelization at the remodeling phase. Angiogenesis and MMP-2 expression were higher in LLLT-treated groups, particularly the LG14 group, which correlated according to the Spearman correlation test. LLLT improves wound healing by enhancing neocollagenesis, increasing the amount of new vessels formed in the tissue (neoangiogenesis), and modulating MMP-2 expression. Epidermal overexpression of MMP-2 was correlated to angiogenic processes.

Photobiomodulation therapy on collagen type I and III, vascular endothelial growth factor, and metalloproteinase in experimentally induced tendinopathy in aged rats

This study investigates the effect of photobiomodulation therapy (PBMT) on collagen type I and III, matrix metalloproteinase (MMP), and vascular endothelial growth factor (VEGF) in experimentally induced tendinopathy in female aged rats. Tendinopathy was induced by the Achilles tendoncollagenase peritendinous. Forty-two Wistar rats (Norvegicus albinus) were used; groups consisted of 36 aged animals (18 months old; mean body weight, 517.7 ± 27.54 g) and 6 adult animals (12 weeks old; mean body weight, 266± 19.30 g). The animals were divided into three groups: control, aged tendinopathy, and aged tendinopathy PBMT; the aged groups were subdivided based on time to euthanasia: 7, 14, and 21 days. PBMT involved a gallium-arsenide-aluminum laser (Theralaser, DMC®) with active medium operating at wavelength 830 ± 10 nm, 50 mW power, 0.028 cm² laser beam, 107 J/cm² energy density, 1.8 W/cm² power density, and an energy of 3 J per point. The laser was applied by direct contact with the left Achilles tendon during 60 s per point at a frequency of three times per week, until the euthanasia date (7, 14, and 21 days). VEGF, MMP-3, and MMP-9 were analyzed by immunohistochemistry, and collagen type I and III by Sirius red. PBMT increased the deposition of collagen type I and III in a gradual manner, with significant differences relative to the group aged tendonitis (p < 0.001), and in relation to VEGF (p < 0.001); decreased expression of MMP-3 and 9 were observed in group aged tendinopathy (p < 0.001). PBMT, therefore, increased the production of collagen type I and III, downregulated the expression of MMP-3 and MMP-9, and upregulated that of VEGF, with age and age-induced hormonal deficiency.

The role of photobiomodulation on gene expression of cell adhesion molecules in diabetic wounded fibroblasts in vitro

Cell adhesion molecules (CAMs) are cell surface glycoproteins that facilitate cell-cell contacts and adhesion with the extracellular matrix (ECM). Cellular adhesion is affected by various disease conditions, such as diabetes mellitus (DM) and inflammation. Photobiomodulation (PBM) stimulates biological processes and expression of these cellular molecules. The aim of this experimental work was to demonstrate the role of PBM at 830nm on CAMs in diabetic wounded fibroblast cells. Isolated human skin fibroblast cells were used. Normal (N-) and diabetic wounded (DW-) cells were irradiated with a continuous wave diode laser at 830nm with an energy density of 5J/cm(2). Real time reverse transcriptase polymerase chain reaction (RT-PCR) was used to determine the relative gene expression of 39 CAMs 48h post-irradiation. Normalized expression levels from irradiated cells were calculated relative to non-irradiated control cells according to the 2^(-ΔΔCt) method. Thirty-one genes were significantly regulated in N-cells (28 were genes up-regulated and three genes down-regulated), and 22 genes in DW-cells (five genes were up-regulated and 17 genes down-regulated). PBM induced a stimulatory effect on various CAMs namely cadherins, integrins, selectins and immunoglobulins, and hence may be used as a complementary therapy in advancing treatment of non-healing diabetic ulcers. The regulation of CAMs as well as evaluating the role of PBM on the molecular effects of these genes may expand knowledge and prompt further research into the cellular mechanisms in diabetic wound healing that may lead to valuable clinical outcomes.

Short-term effects of extremely low-frequency pulsed electromagnetic field and pulsed low-level laser therapy on rabbit model of corneal alkali burn

This study was conducted to investigate the effect of combining extremely low frequency-pulsed electromagnetic field (ELF-PEMF) and low-level laser therapy (LLLT) on alkali-burned rabbit corneas. Fifty alkali-burned corneas of 50 rabbits were categorized into five groups: ELF-PEMF therapy with 2 mT intensity (ELF 2) for 2 h daily; LLLT for 30 min twice daily; combined ELF-PEMF and LLLT (ELF + LLLT); medical therapy (MT); and control (i.e., no treatment). Clinical examination and digital photography of the corneas were performed on days 0, 2, 7, and 14. After euthanizing the rabbits, the affected eyes were evaluated by histopathology. The clinical and histopathologic results were compared between the groups. On days 7 and 14, no significant difference in the corneal defect area was evident between the ELF, LLLT, ELF + LLLT, and MT groups. Excluding the controls, none of the study groups demonstrated a significant corneal neovascularization in both routine histopathology and immunohistochemistry for CD31. Keratocyte loss was significantly higher in the MT group than in the ELF, LLLT, and ELF + LLLT groups. Moderate to severe stromal inflammation in the LLLT group was comparable with that in the MT group and was significantly lower than that in the other groups. In conclusion, combining LLLT and ELF was not superior to ELF alone or LLLT alone in healing corneal alkali burns. However, given the lower intensity of corneal inflammation and the lower rate of keratocytes loss with LLLT, this treatment may be superior to other proposed treatment modalities for healing alkali-burned corneas.

The Role of Matrix Metalloproteinases in Diabetic Wound Healing in relation to Photobiomodulation

The integration of several cellular responses initiates the process of wound healing. Matrix Metalloproteinases (MMPs) play an integral role in wound healing. Their main function is degradation, by removal of damaged extracellular matrix (ECM) during the inflammatory phase, breakdown of the capillary basement membrane for angiogenesis and cell migration during the proliferation phase, and contraction and remodelling of tissue in the remodelling phase. For effective healing to occur, all wounds require a certain amount of these enzymes, which on the contrary could be very damaging at high concentrations causing excessive degradation and impaired wound healing. The imbalance in MMPs may increase the chronicity of a wound, a familiar problem seen in diabetic patients. The association of diabetes with impaired wound healing and other vascular complications is a serious public health issue. These may eventually lead to chronic foot ulcers and amputation. Low intensity laser irradiation (LILI) or photobiomodulation (PBM) is known to stimulate several wound healing processes; however, its role in matrix proteins and diabetic wound healing has not been fully investigated. This review focuses on the role of MMPs in diabetic wound healing and their interaction in PBM.

Study of stiffness effects of poly(amidoamine)-poly(n-isopropyl acrylamide) hydrogel on wound healing

The mechanical miss-match between the host and an implanted foreign body is one of the primary causes for implantation failure. To enhance the efficacy in wound repair, we developed stiffness-tunable temperature-sensitive hydrogels composed of poly(amidoamine) (PAA)-based poly(n-isopropyl acrylamide) (PNIPAM). PNIPAM-PAA hydrogels with three different stiffness fabricated by varying the concentrations of poly(amidoamine) were chosen for morphology and rheology tests. The degradation rate and cell compatibility of gels were also characterized. The PAA-PNIPAM hydrogels were then tested in a wound healing model of mice with full-thickness skin loss. We found that the stiffness of hydrogels has an impact on the wound healing process mainly by regulating the cell activities in the proliferation phase. PNIPAM-PAA hydrogels with appropriate stiffness reduce scar formation and improve wound healing by promoting myofibroblast transformation, keratinocytes proliferation, extracellular matrix synthesis and remodeling. Moreover, the stiffness of hydrogels impact on the secretion of TGF-β1 and bFGF, which play an important role in skin wound healing. These results suggest that the therapeutic effects of hydrogels in skin wound healing can by regulated by hydrogels' stiffness.

Phototherapy improves wound healing in rats subjected to high-fat diet

This study aimed to compare the phototherapy effects on wound healing in rats submitted to normal and high-fat diets. Thirty-six rats received normal lipidic diet (NL) and 36 high lipidic (HL) diet for 45 days. The nutritional status was measured by body mass, blood glucose, total cholesterol, and triglycerides levels. Four experimental groups were performed according light (L) therapy applied "on" or "off" (660 nm, 100 mW, 70 J/cm(2), 2 J) on 1.5-mm-punched dorsum skin wounds as NLL+, NLL-, HLL+, and HLL-. The wound healing rate (WHR) and oxidative stress markers were analyzed on 2nd, 7th, and 14th days. Despite no difference among body mass, the HL rats presented higher blood glucose, total cholesterol, and triglycerides levels than NL rats. Respectively, on the 2nd and 14th days, the HLL+ group presented the highest WHRs (0.38 ± 0.16/0.97 ± 0.02) among all groups, while the HLL- (-0.002 ± 0.12/0.81 ± 12.1) the lowest WHRs. Hydroxyproline level was lower in HLL- (6.41 ± 1.09 μg/mg) than HLL+ (7.71 ± 0.61 μg/mg) and also NLL+ (9.33 ± 0.84 μg/mg). HLL+ presented oxidative stress markers similar to normal control group (NLL-) during follow up and highest antioxidant defense on 7th day. The results showed phototherapy accelerated the cutaneous wound healing by modulating oxidative stress in rats with metabolic disorders under a high-fat diet.

Phototherapy promotes healing of cutaneous wounds in undernourished rats

BACKGROUND

Various studies have shown that phototherapy promotes the healing of cutaneous wounds.

OBJECTIVE

To investigate the effect of phototherapy on healing of cutaneous wounds in nourished and undernourished rats.

METHODS

Forty rats, 20 nourished plus 20 others rendered marasmus with undernourishment, were assigned to four equal groups: nourished sham, nourished Light Emitting Diode treated, undernourished sham and undernourished Light Emitting Diode treated. In the two treated groups, two 8-mm punch wounds made on the dorsum of each rat were irradiated three times per week with 3 J/cm2 sq cm of combined 660 and 890 nm light; wounds in the other groups were not irradiated. Wounds were evaluated with digital photography and image analysis, either on day 7 or day 14, with biopsies obtained on day 14 for histological studies.

RESULTS

Undernourishment retarded the mean healing rate of the undernourished sham wounds (p < 0.01), but not the undernourished Light emission diode treated wounds, which healed significantly faster (p < 0.001) and as fast as the two nourished groups. Histological analysis showed a smaller percentage of collagen in the undernourished sham group compared with the three other groups, thus confirming our photographic image analysis data.

CONCLUSION

Phototherapy reverses the adverse healing effects of undernourishment. Similar beneficial effects may be achieved in patients with poor nutritional status.

Organic light emitting diode improves diabetic cutaneous wound healing in rats

A major complication for diabetic patients is chronic wounds due to impaired wound healing. It is well documented that visible red wavelengths can accelerate wound healing in diabetic animal models and patients. In vitro and in vivo diabetic models were used to investigate the effects of organic light emitting diode (OLED) irradiation on cellular function and cutaneous wound healing. Human dermal fibroblasts were cultured in hyperglycemic medium (glucose concentration 180 mM) and irradiated with an OLED (623 nm wavelength peak, range from 560 to 770 nm, power density 7 or 10 mW/cm2 at 0.2, 1, or 5 J/cm2). The OLED significantly increased total adenosine triphosphate concentration, metabolic activity, and cell proliferation compared with untreated controls in most parameters tested. For the in vivo experiment, OLED and laser (635 ± 5 nm wavelength) treatments (10 mW/cm2 , 5 J/cm2 daily for a total of seven consecutive days) for cutaneous wound healing were compared using a genetic, diabetic rat model. Both treatments had significantly higher percentage of wound closure on day 6 postinjury and higher total histological scores on day 13 postinjury compared with control. No statistical difference was found between the two treatments. OLED irradiation significantly increased fibroblast growth factor-2 expression at 36-hour postinjury and enhanced macrophage activation during initial stages of wound healing. In conclusion, the OLED and laser had comparative effects on enhancing diabetic wound healing.

The effect of low-level laser irradiation on sperm motility, and integrity of the plasma membrane and acrosome in cryopreserved bovine sperm

BACKGROUND AND OBJECTIVE

Freezing changes sperm integrity remarkably. Cryopreservation involves cooling, freezing, and thawing and all these contribute to structural damage in sperm, resulting in reduced fertility potential. Low-level laser irradiation (LLLI) could increase energy supply to the cell and cause reactive oxygen species reduction (ROS), contributing to the restoration of oxygen consumption and adenosine triphosphate synthesis (ATP) in the mitochondria. Our goal was to analyze the effects of low-level laser irradiation on sperm motility and integrity of the plasma membrane and acrosome in cryopreserved bovine sperm.

STUDY DESIGN/MATERIALS AND METHODS

We analyzed 09 samples of bull semen (Bos taurus indicus), divided into three groups: a control group without laser irradiation, a 4J group subjected to a laser irradiation dose of 4 joules, and a 6J group subjected to dose of 6 joules. Samples were divided for the analysis of cell viability and acrosomal membrane integrity using flow cytometry; another portion was used for motion analysis. Irradiation was performed in petri dishes of 30 mm containing 3 ml of semen by an aluminum gallium indium phosphide laser diode with a wavelength of 660 nm, 30 mW power, and energy of 4 and 6 joules for 80 and 120 seconds respectively. Subsequently, the irradiated and control semen samples were subjected to cryopreservation and analyzed by flow cytometry (7AAD and FITC-PSA) using the ISAS--Integrated Semen Analysis System.

RESULTS

Flow cytometry showed an increase in the percentage of live sperm cells and acrosome integrity in relation to control cells when subjected to irradiation of low-power laser in two different doses of 4 and 6 joules (p < 0.05). In the analysis of straightness, percentage of cell movement, and motility, a dose of 4 joules was more effective (p < 0.05).

CONCLUSION

We conclude that LLLI may exert beneficial effects in the preservation of live sperm. A dose of 4 joules prior to cryopreservation was more effective than a dose of 6 joules in preserving sperm motility.

Effect of low-level laser therapy in an experimental model of osteoarthritis in rats evaluated through Raman spectroscopy

OBJECTIVE

This work aimed to investigate the biochemical changes associated with low-level laser therapy (LLLT) using 660 and 780 nm, on a well-established experimental model of osteoarthritis (OA) in the knees of rats with induced collagenase, using histomorphometry and Raman spectroscopy.

MATERIALS AND METHODS

Thirty-six Wistar rats were divided into four groups: control (GCON, n=9), collagenase without treatment (GCOL, n=9), collagenase with LLLT 660 nm treatment (G660, n=8), and collagenase with LLLT 780 nm treatment (G780, n=10). LLLT protocol was: 30 mW power output, 10 sec irradiation time, 0.04 cm(2) spot size, 0.3 J energy, 0.75 W/cm(2) irradiance, and 7.5 J/cm(2) fluence per session per day, during 14 days. Then, knees were withdrawn and submitted to histomorphometry and Raman spectroscopy analysis. Principal components analysis (PCA) and Mahalanobis distance were employed to characterize the spectral findings.

RESULTS

Histomorphometry revealed a significant increase in the amount of collagen III for the group irradiated with 660 nm. The Raman bands at 1247, 1273, and 1453 cm(-1) (from principal component score PC2), attributed to collagen type II, and 1460 cm(-1) (from PC3), attributed to collagen type III, suggested that the LLLT causes acceleration in cellular activity, especially on the cells that repair cartilage, accelerating the breakdown of cartilage destroyed by collagenase and stimulating the fibroblast to synthesize repairing collagen III.

CONCLUSIONS

LLLT accelerated the initial breakdown of cartilage destroyed by collagenase and stimulated the fibroblast to synthesize the repairing collagen III, suggesting a beneficial effect of LLLT on OA.