Effects of the Low-Level Laser Therapy (LLLT) in the process of healing diabetic foot ulcers

Adherence to Self-care and Quality of Life of Patients with Diabetic Foot Ulcers Treated with Low-Level Laser Therapy: An Exploratory Study

OBJECTIVE

To evaluate the quality of life (QoL) of patients with a diabetic foot ulcer undergoing treatment with low-level laser therapy (LLLT) at 904 nm and its association with self-care.

METHODS

In this randomized, exploratory study, participants were divided into the following four groups: control group (CG) with LLLT placebo, LLLT group 1 (LG1) at 10 J/cm2, LLLT group 2 (LG2) at 8 J/cm2, and LLLT group 3 (LG3) at 4 J/cm2. Participants received light therapy (or placebo) twice a week, for a total of 20 sessions. Researchers assessed participants' QoL using the Short-Form 36 questionnaire.

RESULTS

Sixty-two participants were included in the analysis (CG = 18, LG1 = 14, LG2 = 17, LG3 = 13). The LG1 group showed a higher proportion of healing, whereas the CG group showed a lower proportion than the other groups. The LG1 group showed a relationship between physical limitations and blood glucose monitoring, pain and foot care, and general health status (GHS) and foot care. The GL2 group showed a relationship between physical limitations and blood glucose monitoring, vitality and foot care, and GHS and diet.

CONCLUSIONS

Low-level laser therapy had a positive impact on QoL as assessed by the Short-Form 36 questionnaire (functional capacity, vitality, and pain domains), and there was a positive association between QoL and self-care in the LLLT groups (physical limitations, pain, GHS, and vitality domains).

A meta-analysis and systematic review of photodynamic therapy for diabetic foot ulcers

BACKGROUND

Diabetic foot ulcer (DFU) is a chronic and challenging condition, addressed through various treatments including photodynamic therapy (PDT) and standard of care (SOC), yet lacking consensus on the optimal approach. This study presents a comprehensive meta-analysis of randomized controlled trials to evaluate the efficacy and safety of PDT versus SOC in managing DFU.

METHODS

An extensive literature search was conducted across PubMed, Embase, and the Cochrane Library databases to identify RCTs that compared the effectiveness of PDT with SOC in treating DFU. The primary metrics evaluated included changes in ulcer area, wound healing indices, and pain levels experienced by the patients.

RESULTS

This meta-analysis incorporated data from 6 RCTs, encompassing 458 patients with 467 DFUs. The analysis indicated that while PDT led to a faster reduction in ulcer size compared to SOC, the difference was not statistically significant [mean difference (MD): 2.73cm², 95 % Confidence Interval (CI) -2.98 to 8.44; p > 0.05]. However, a notable improvement was observed in the wound healing rate in the PDT group [MD: 29.26 %, 95 % CI 7.24 to 51.28; p = 0.01]. Based on the Visual Analog Scale (VAS), pain assessment revealed no significant difference between the two treatment groups [MD: 2.35, 95 % CI -2.36 to 7.06; p = 0.33].

CONCLUSION

The study suggests that PDT might offer an enhanced healing rate for DFUs compared to SOC alone, potentially leading to improved patient outcomes. Importantly, our findings highlight the superiority of photodynamic therapy in accelerating ulcer healing without an associated increase in complications.

PROSPERO

2023 CRD42023493930.

Photobiomodulation CME part II: Clinical applications in dermatology

Photobiomodulation (PBM) is an emerging treatment modality in dermatology with increasing office and home-based use. PBM is the use of various light sources in the red light (620-700 nm) and near-infrared (700-1440 nm) spectrum as a form of light therapy. PBM is often administered through low-level lasers or light-emitting diodes. Studies show that PBM can be used effectively to treat conditions secondary to cancer therapies, alopecia, ulcers, herpes simplex virus, acne, skin rejuvenation, wounds, and scars. PBM offers patients many benefits compared to other treatments. It is noninvasive, cost-effective, convenient for patients, and offers a favorable safety profile. PBM can be used as an alternative or adjuvant to other treatment modalities including pharmacotherapy. It is important for dermatologists to gain a better clinical understanding of PBM for in-office administration and to counsel patients on proper application for home-use devices to best manage safety and expectations as this technology develops. PBM wavelengths can induce varied biological effects in diverse skin types, races, and ethnicities; therefore, it is also important for dermatologists to properly counsel their skin of color patients who undergo PBM treatments. Future clinical trials are necessary to produce standardized recommendations across conditions and skin types.

Chronic Leg Ulcer Associated with Cutaneous IgG4-Related Disease

Chronic leg ulcer occurs in up to 13% of the general population and leads to economic and health care burdens. Approximately 20% of chronic nonhealing wounds are related to autoimmune diseases or vasculitis. Of these, chronic wounds associated with IgG4-related disease, a group of fibroinflammatory disorders that can have cutaneous and systemic involvement, are rarely reported. This case report describes a chronic leg ulcer associated with cutaneous IgG4-related disease. In addition to disease control with anti-inflammatory agents, following the principles of wound management and providing adjuvant wound treatment (eg, debridement, dressing, photobiomodulation therapy, or hyperbaric oxygen therapy) can promote the wound healing process.

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.

Diabetic foot wound ulcer management by laser therapy: A meta-analysis

A meta-analysis examination was implemented to review diabetic foot wound ulcer (DFWU) management by laser therapy (LT). A broad literature examination until May 2023 was done and 1357 interconnected examinations were revised. The 26 elected examinations, enclosed 1067 personals with DFWU were in the utilized examinations 'starting point, 540 of them were utilizing LT, and 527 were utilizing control. Odds ratio (OR) and 95% confidence intervals (CIs) were utilized to appraise the DFWUs management by LT by the dichotomous and continuous approach and a fixed or random model. LT had significantly higher ulcer size decreases (MD, 17.04; 95% CI, 12.48-21.59, p < 0.001) with high heterogeneity (I2  = 99%), and complete healing rate (OR, 2.88; 95% CI, 1.89-4.37, p < 0.001) with no heterogeneity (I2  = 0%) compared with control in personals with DFWU. LT had significantly higher ulcer size decreases, and complete healing rate compared to control in personals with DFWU. Nevertheless, exercise caution while interacting with its values since all the chosen examinations were found with a low sample size for the comparisons in the meta-analysis.

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.

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.

Photobiomodulation, as additional treatment to traditional dressing of hard-to-heal venous leg ulcers, in frail elderly with municipality home healthcare

The main objectives of the study were to explore whether laser Photobiomodulation (PBM) in addition to traditional dressing of hard-to-heal venous leg ulcer, reduced healing time of the ulcer and if the duration of the ulcer before PBM impacted the treatment time with PBM to healing. The intervention group was frail, elderly patients with home healthcare in the municipality of Skellefteå, registered in the Swedish quality registry RiksSar for ulcer treatment with hard-to-heal venous leg ulcer. The control group with equivalent physical conditions was obtained from the same quality registry. Definition of hard-to-heal ulcer was six weeks duration or more. The PBM was performed two times per week with laser type infrared GaAs, 904nm, 60mW, and 700Hz, targeting lymphatic area and ulcer area. Laser type red visible, GaAllnp, 635nm, 75mW and 250Hz, targeting ulcer area. The intervention group treated with PBM in addition to traditional dressing healed significantly faster than the control group with a mean of 123 days (p = 0.0001). Duration of the ulcer before PBM did not impact the healing time. To conclude, the findings indicate that using PBM in addition to dressing may have multiple benefits on hard-to-heal venous leg ulcer, saving valuable time and resources for patients, healthcare providers, and institutions.

Clinical Effect of Photobiomodulation on Wound Healing of Diabetic Foot Ulcers: Does Skin Color Needs to Be Considered?

Diabetic foot ulcers (DFUs) are one of the most common complications of diabetes. DFUs impede patients' quality of life and are known to be unresponsive to conventional therapy. Photobiomodulation (PBM) is a pain-free, noninvasive treatment method that has been shown to promote chronic wound healing and has been successfully used for the treatment of DFUs. Since skin tone and color can affect the way light interacts with tissue, studies should take this into consideration when determining protocols for the use of PBM. This review is aimed at critically evaluating data of existing studies conducted to evaluate the clinical effect of PBM on DFUs, taking skin color into consideration. A literature search was conducted and resulted in articles on cell studies, animal studies, and clinical trials. Only 13 clinical trials and 2 clinical case studies were adopted and used in this review. All the clinical trials adopted for this review show evidence that PBM together with conventional treatment results in an increased healing rate of DFUs; however, only one study adjusted their protocol according to skin color. There are not enough studies conducted on people of color to determine the safety and efficacy of PBM therapy in such ethnic groups. Future randomized, placebo-controlled clinical trials are necessary on PBM and DFUs and should take skin color into consideration.

Low-laser light therapy in venous ulcer healing: a randomized clinical trial

OBJECTIVES

to compare the effect of adjuvant low-laser light therapy versus conventional treatment alone on venous ulcer healing.

METHODS

this is a randomized clinical trial with 40 patients randomized equally to a control group (topical and compressive treatment) and intervention group (adjuvant low-laser light therapy). Outcomes of interest were Wound Healing: Secondary Intention and Tissue Integrity: Skin & Mucous Membranes, as described in the Classification of Nursing Outcomes/NOC.

RESULTS

groups with similar sociodemographic and clinical characteristics. Eighty-two ulcers were assessed, with an average duration of 1 to 5 years, in 1,066 nursing consultations, with a statistically significant difference in the time and number of healed ulcers (intervention group). There was a significant improvement in the nursing outcomes under study and in eight clinical indicators.

CONCLUSIONS

low-laser light therapy improves and reduces tissue regeneration time, contributing to advances in wound treatment.

Efficacy and safety of CO2 laser in the treatment of chronic wounds: A Retrospective Matched Cohort Trial

OBJECTIVES

Treating chronic cutaneous wounds is challenging, and debridement is a central concept in treating them. Studies have shown that CO₂ laser debridement can control local infection and promote the wound healing process. The present study aimed to investigate the efficacy and safety of fully ablative CO₂ laser debridement compared to routine surgical debridement in the treatment of chronic wounds.

METHODS

The retrospective cohort study was conducted on patients with chronic (>1 month) cutaneous wounds (≥1 cm² ) between December 1, 2017, and December 1, 2020, in the Wound Healing Center at Shanghai Ruijin Hospital, China. Patients treated with CO₂ laser debridement with a DEKA SmartXide2 C80 (DEKA) (the CO₂ laser group) were compared with matched control patients with similar baseline characteristics who had undergone routine surgical debridement (the routine group). The primary outcome was time-to-heal (days) for chronic wounds in two groups, and secondary outcomes included the wound area and BWAT (Bates-Jensen wound assessment tool) score before treatment, and at 1, 2, 3, and 4 weeks after treatment.

RESULTS

The study included 164 patients (82 in the CO₂ laser group and 82 matched in the routine group). The time-to-heal for patients in the CO₂ laser group (41.30 ± 17.11) was significantly shorter than that of the patients in the routine group (48.51 ± 24.32) (p = 0.015). At 3 and 4 weeks after treatment, the absolute wound area of the CO₂ laser group was significantly smaller than that of the routine group. Also, the CO₂ laser group exhibited a significantly lower relative area at 2, 3, and 4 weeks after treatment. The CO₂ laser group yielded significantly lower BWAT scores at 2, 3, and 4 weeks after treatment. Additionally, the relative BWAT score was significantly lower in the CO₂ laser group than the relative scores in the routine group at 2, 3, and 4 weeks after treatment. No adverse events related to the treatments were observed in either group during the study period.

CONCLUSIONS

The present study has shown that fully ablative CO₂ laser debridement has several advantages over routine sharp surgical debridement. It is superior at ameliorating wound status and reducing wound area, and it also significantly reduces the time-to-heal for chronic wounds, without causing any adverse events.

Assessment of wound area reduction on chronic wounds in dogs with photobiomodulation therapy: A randomized controlled clinical trial

Background and Aim

Chronic wounds are a clinical problem and require intensive standard wound care. However, this is sometimes insufficient to promote healing. Photobiomodulation therapy (PBMT) can be used as an adjunctive therapy to improve wound healing. Various PBMT devices with different properties and parameter settings as well as different animal species can influence a variety of clinical outcomes. This study aims to assess the use of 830 nm PBMT or simultaneous superpulsed and multiple wavelengths (SPMW; 660, 875, and 905 nm) PBMT on chronic wounds in client-owned dogs.

Materials and Methods

This study included 21 client-owned dogs with chronic wounds allocated into three groups: (1) Control group (C) treated with irrigated saline and without PBMT (n=7); (2) L1 group treated with irrigated saline together with the radiation of 830 nm PBMT (n=7); and (3) L2 group treated with irrigated saline together with the radiation of simultaneous SPMW-PBMT (n=7). Wound healing was assessed on the basis of wound size reduction as a percentage of wound area every 2^nd day for 15 days using image analysis software (ImageJ software^®, National Institutes of Health, Rockville, Maryland, USA).

Results

A significant difference in the percentage of wound area reduction was noted between the C and PBMT groups (L1 and L2; p<0.05). The average percentages of wound area reduction at the end of the study (15 days) were 42.39±20.58, 56.98±24.82, and 61.81±27.18 in the C, L1, and L2 groups, respectively. A steady decrease in wound size was noted in both PBMT and non-PBMT groups, and coefficients were 7.77, 8.95, and 10.01 in the C, L1, and L2 groups, respectively. The percentage of wound area reduction was found to be significantly different between the PBMT and non-BPMT groups on day 7 (p<0.05).

Conclusion

Based on the results of the current study, using either 830 nm PBMT or simultaneous SPMW-PBMT can accelerate the chronic wound healing process in dogs with a significant reduction in wound area. Therefore, it can be used as an adjunctive therapy to improve wound healing in dogs with reduced treatment duration.

A Systematic Review and Meta-Analysis of the Effects of Low-Level Laser Therapy in the Treatment of Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) are considered one of the most aggressive and expensive complications of diabetes. Low-level laser therapy (LLLT) has been highlighted as a potential modality of treatment to accelerate the healing of ulcers. This systematic review and meta-analysis aimed to investigate the efficacy of LLLT in the treatment of DFU and identify the LLLT application parameters recommended for the treatment of DFU over the past 10 years. A systematic search was conducted in PubMed, BVS, PEDro, Scopus, Web of Science, and CINAHL up to March 31, 2019. Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, randomized controlled trials (RCTs) that assessed the effect of LLLT on the treatment of DFU were included. Thirteen RCTs with a total of 361 participants were included in this review. Three RCTs reported a reduction in the percentage size of the ulcers and were included in the meta-analysis. The meta-analysis of the percentage size difference demonstrated a significant reduction in ulcer size in the LLLT group compared with controls (22.96 [95% confidence interval = 18.22-27.69; z = 9.51, P < .0001]). Treatment with 632.8 to 685 nm, 50 mW/cm2, 3 to 6 J/cm2, and irradiation for 30 to 80 seconds, 3 times weekly for a month is of benefit to patients with DFU. LLLT is effective and safe for the treatment of DFU. Additionally, well-designed, high-quality studies are needed to allow its ideal parameterization for clinical practice.

Photobiomodulation and diabetic foot and lower leg ulcer healing: A narrative synthesis

PURPOSE

To provide a comprehensive narrative review and critical appraisal of research investigating photobiomodulation (PBM), formerly known as low level laser therapy which includes lasers and light emitting diodes (LEDs), as a treatment to promote diabetic foot and lower leg ulcer (DFU) healing for humans.

MATERIALS AND METHODS

Pubmed, CINAHL, Scopus, and OVID Medline databases were used to find relevant studies published between January 2000 and January 2020. Reference lists of identified articles were scanned for additional studies that might have been missed in the database searches.

RESULTS

A total of 13 studies, with a total of 417 participants, were included in this review.

DISCUSSION

The studies were critically appraised using the PEDro scale, which revealed weaknesses in study designs such as small sample sizes and problems with reproducibility with respect to the laser protocols. Characteristics of PBM that improved wound healing were wavelengths of 630 nm-660 nm and infrared wavelengths of 850 or 890 nm, and radiant exposure levels of 3 J/cm²-7 J/cm². PBM was beneficial for superficial and deep DFUs. Controlled blood glucose levels and adherence to best practices (pressure off-loading, optimized wound dressing changes, appropriate debridement, etc.) could have been a factor in the beneficial outcomes.

CONCLUSION

Regardless of the laser characteristics chosen, in the majority of studies PBM as a treatment for DFUs improved healing rate when compared with standard wound care alone. However, weaknesses across the studies indicate that further research is required.

Treatment of diabetic foot ulcers in a frail population with severe co-morbidities using at-home photobiomodulation laser therapy: a double-blind, randomized, sham-controlled pilot clinical study

PURPOSE

To evaluate the safety and efficacy of an at-home photobiomodulation (PBM) device for the treatment of diabetic foot ulcers (DFUs) in a frail population with severe comorbidities.

METHODS

Prospective, randomized, double-blind, sham-controlled pilot study. Patients (age = 63 ± 11 years, male:female 13:7) with insulin-dependent diabetes type 2, neuropathy, peripheral artery disease, significant co-morbidities, and large osteomyelitis-associated DFUs (University of Texas grade ≥ III) were randomized to receive active (n = 10) or sham (n = 10) at-home daily PBM treatments (pulsed near-infrared 808 nm Ga-Al-As laser, 250 mW, 8.8 J/cm²) for up to 12 weeks in addition to standard care. The primary outcome was the %wound size reduction. The secondary was adverse events.

RESULTS

With the numbers available, PBM-treated group had significantly greater %reduction compared to sham (area [cm²], baseline vs endpoint: PBM 10[20.3] cm² vs 0.2[2.4] cm²; sham, 7.9 [12.0] cm² vs 4.6 [13.8] cm², p = 0.018 by Mann-Whitney U test). Wound closure > 90% occurred in 7 of 10 PBM-treated patients but in only 1 of 10 sham patients (p = 0.006). No adverse device effects were observed.

CONCLUSIONS

Photobiomodulation at home, in addition to standard care, may be effective for the treatment of severe DFUs in frail patients with co-morbidities and is particularly relevant at these times of social distancing. Our preliminary results justify the conduction of a larger clinical trial. ClinicalTrials.gov: NCT01493895.

Patients with Diabetes Complicated by Peripheral Artery Disease: the Current State of Knowledge on Physiotherapy Interventions

Diabetes mellitus (DM) is one of the major public health problems that account for morbidity, mortality, and disability worldwide. The presence of DM increases the risk of peripheral artery disease (PAD), as well as accelerates its course, making these patients more susceptible to ischemic events and impaired functional status. Unfortunately, alternative treatments for vascular complications in diabetes are poorly researched. Physiotherapy (kinesitherapy combined with different physical therapy agents) in individuals with DM and coexisting PAD may offer an important complementary therapy alternative. Early therapeutic measures can significantly improve patient outcomes, reduce cardiovascular risk, and improve daily life quality. The article provides an update on the current state of knowledge on physiotherapy interventions in the course of DM in patients with coexisting PAD.

The effect of low-level laser therapy on diabetic foot ulcers: A meta-analysis of randomised controlled trials

Our purpose was to perform a meta‐analysis to evaluate the effect of Low‐level laser therapy (LLLT) on diabetic foot ulcers (DFUs). The PubMed, Cochrane, Embase, Web of Science, Chinese BioMedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), VIP and Wanfang databases were searched systematically up to August 27, 2020. Studies that met the inclusion criteria were included in the analysis. A total of 13 randomised controlled trials (RCTs) and 413 patients were analysed. Compared with the control group, LLLT significantly increased the complete healing rate (risk ratio [RR] = 2.10, 95% confidence interval [CI] 1.56‐2.83, P < .00001), reduced the ulcer area (standardised mean difference [SMD] = 3.52, 95% CI 1.65‐5.38, P = .0002), and shortened the mean healing time (SMD = −1.40, 95% CI −1.90 to −0.91, P < .00001) of patients with DFUs. The quality of the evidence was very low according to the GRADE system. LLLT is a promising and effective adjuvant treatment to accelerate the healing of DFUs. Further evidence from larger samples and higher quality RCTs is needed to prove the effect of LLLT and to determine the most appropriate parameters for the healing of DFUs.

Retrospective Matched Case-Control Study on the Use of CO2 Laser for the Treatment of Nonhealing Diabetic Foot Ulcers: The DULCIS-2 (Diabetic ULcer, CO2 Laser, and Infections) Study

PURPOSE

Infection, which is one of the possible complications of diabetic foot ulcers (DFUs), makes the treatment of ulcers challenging because of its negative impact on healing processes and the high prevalence of multiresistant germs. This study is aimed at verifying the effect of a surgical CO₂ laser (which reduces the bacterial load and allows a more accurate debridement), as compared with the traditional lancets, on the healing rate of DFU.

METHODS

The present case-control retrospective analysis was performed on patients with chronic (>6 months) DFU with Texas grade >1, treated with 80 W surgical CO₂ laser (DEKA SmartXide2 C80, El.En. Group) and compared with a matched sample of patients with similar characteristics, who were treated with a traditional surgical approach. The debridement was performed trying to achieve the complete removal of nonviable tissues. The principal endpoint was the proportion of patients healed at 6 months. All analyses were carried out with SPSS 25.0. The study protocol was approved by the local ethical committee.

RESULTS

This study included 118 patients (59 cases and 59 controls). At 6 months, the proportion of healing patients was 35% and 18% in cases and controls, respectively (P = .034). The corresponding figure at 1 year was 62% and 38% (P = .009), whereas no difference was observed at 1, 2, and 3 months. No serious adverse event was observed.

CONCLUSIONS

In this article, we show for the first time that CO₂ laser treatment, in comparison with traditional surgical approaches, can be associated with an increased healing rate in patients with DFU.

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.

Biostimulative effect of laser on growth of mesenchymal stem/stromal cells in vitro

Introduction

Human adipose tissue-derived mesenchymal stem/stromal cells (hAT-MSCs) are multipotent stromal cells with a high potential application in tissue engineering and regenerative medicine. Laser irradiation of the place where the cells were implanted can stimulate their proliferation, increase the secretion of growth factors and thus increase the therapeutic effect.

Aim

To evaluate the influence of two lasers: Er:YAG and diode on the growth of hAT-MSCs in vitro.

Material and methods

hAT-MSCs were isolated from human subcutaneous adipose tissue. Immunophenotype of hAT-MSCs was confirmed by flow cytometry. Multipotency of hAT-MSCs was confirmed by differentiation into adipogenic, osteogenic and chondrogenic lineages. hAT-MSCs were irradiated with Er:YAG laser (wavelength 2940 nm, frequency 5, 10 Hz, doses: 0.1–1.2 J/cm²) for 2 s and 4 s and diode laser (wavelength 635 nm and doses: 1–8 J/cm²) for 5, 10, 20, 30 and 40 s. Cell viability was analysed 24 h after the exposure using MTT assay.

Results

Growth stimulation of hAT-MSCs after 5 Hz Er:YAG laser exposure, 0.1 J/cm² dose for 4 s and 0.3 J/cm² dose for 4 s was shown in comparison with the control group. Significant growth stimulation of hAT-MSCs after diode laser irradiation in doses of 1–4 J/cm² was demonstrated compared to the control group.

Conclusions

The presented results indicate that both lasers, Er:YAG and diode can be used to stimulate stem/stromal cell growth in vitro. The biostimulative effect of laser therapy on stromal cells may be used in the future in aesthetic dermatology in combined laser and cell therapy.

Efeitos da laserterapia de baixa intensidade na cicatrização de úlceras nos pés em pessoas com diabetes mellitus

Objetivo: Identificar os efeitos da laserterapia de baixa intensidade na cicatrização do pé diabético. Método: Revisão sistemática nas bases de dados PubMed, LILACS, SciELO, CINAHL, Cochrane, Web of Science e Scopus, em que foram identificados 73 artigos, dos quais seis foram incluídos na amostra final, após verificação dos critérios de elegibilidade. Resultados: Os artigos apontaram como efeitos da laserterapia a efetividade na progressão do processo de reparo tecidual do pé diabético, alívio da dor, ação antiinflamatória, aumento da perfusão tecidual da lesão e melhora da resposta vascular e do sistema nervoso. Conclusão: O laser é uma terapia adjuvante que pode acelerar o processo de cicatrização da lesão, diminuir a dor, melhorar a neovascularização e, assim, minimizar o risco de complicações, como amputação do membro inferior e melhora da qualidade de vida de pessoas com diabetes e integridade da pele prejudicada.

Effects of low-level laser therapy on the healing of foot ulcers in people with diabetes mellitus

Objective: Identify the effects of low-level laser therapy on the healing of diabetic foot. Method: Systematic review of the PubMed, LILACS, SciELO, CINAHL, Cochrane, Web of Science and Scopus databases, in which 92 articles were identified and six were included in the final sample after the eligibility criteria. Results: The articles pointed out as effects of laser therapy the effectiveness in the progression of the tissue repair process of the diabetic foot, pain relief, anti-inflammatory action, increased tissue perfusion of the lesion and improvement of the vascular response and the nervous system. Conclusion: Laser is an adjuvant therapy that can accelerate the wound healing process, relieve pain, improve neovascularization, and thus minimize the risk of complications, such as lower limb amputation and improvement of quality of life for people with diabetes and impaired skin integrity.

Effectiveness of interventions to enhance healing of chronic foot ulcers in diabetes: a systematic review

The management of diabetic foot ulcers (DFU) remains a challenge, and there is continuing uncertainty concerning optimal approaches to wound healing. The International Working Group of the Diabetic Foot (IWGDF) working group on wound healing has previously published systematic reviews of the evidence in 2008, 2012 and 2016 to inform protocols for routine care and to highlight areas which should be considered for further study. The working group has now updated this review by considering papers on the interventions to improve the healing of DFU's published between June 2014 and August 2018. Methodological quality of selected studies was independently assessed by a minimum of two reviewers using the recently published 21-point questionnaire as recommended by IWGDF/European Wound Management Association, as well as the previously incorporated Scottish Intercollegiate Guidelines Network criteria. Of the 2275 papers identified, 97 were finally selected for grading following full text review. Overall, there has been an improvement in study design and a significant rise in the number of published studies. While previous systematic reviews did not find any evidence to justify the use of newer therapies, except for negative pressure wound therapy in post-surgical wounds, in this review we found additional evidence to support some interventions including a sucrose-octasulfate dressing, the combined leucocyte, fibrin and platelet patch as well as topical application of some placental membrane products, all when used in addition to usual best care. Nonetheless, the assessment and comparison of published trials remains difficult with marked clinical heterogeneity between studies: in patient selection, study duration, standard of usual care provision and the timing and description of the clinical endpoints.

Guidelines on use of interventions to enhance healing of chronic foot ulcers in diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. In conjunction with advice from internal and external reviewers and expert consultants in the field, this update is based on a systematic review of the literature centred on the following: the Population (P), Intervention (I), Comparator (C) and Outcomes (O) framework; the use of the SIGN guideline/Cochrane review system; and the 21 point scoring system advocated by IWGDF/EWMA. This has resulted in 13 recommendations. The recommendation on sharp debridement and the selection of dressings remain unchanged from the last recommendations published in 2016. The recommendation to consider negative pressure wound therapy in post-surgical wounds and the judicious use of hyperbaric oxygen therapy in certain non-healing ischaemic ulcers also remains unchanged. Recommendations against the use of growth factors, autologous platelet gels, bioengineered skin products, ozone, topical carbon dioxide, nitric oxide or interventions reporting improvement of ulcer healing through an alteration of the physical environment or through other systemic medical or nutritional means also remain. New recommendations include consideration of the use of sucrose-octasulfate impregnated dressings in difficult to heal neuro-ischaemic ulcers and consideration of the use of autologous combined leucocyte, platelet and fibrin patch in ulcers that are difficult to heal, in both cases when used in addition to best standard of care. A further new recommendation is the consideration of topical placental derived products when used in addition to best standard of care.

Photobiomodulation plus Adipose-derived Stem Cells Improve Healing of Ischemic Infected Wounds in Type 2 Diabetic Rats

In this study, we sought to investigate the impact of photobiomodulation and adipose-derived stem cells (ADS), alone and in combination, on the maturation step of wound healing in an ischemic infected delayed healing wound model in rats with type 2 diabetes mellitus (DM2). We randomly divided 24 adult male rats into 4 groups (n = 6 per group). DM2 plus an ischemic delayed healing wound were induced in all rats. The wounds were infected with methicillin-resistant Staphylococcus aureus. Group 1 was the control (placebo) group. Group 2 received only photobiomodulation (890 nm, 80 Hz, 0.324 J/cm², and 0.001 W/cm²). Group 3 received only the allograft ADS. Group 4 received allograft ADS followed by photobiomodulation. On days 0, 4, 8, 12, and 16, we performed microbiological examination (colony forming units, [CFU]), wound area measurement, wound closure rate, wound strength, and histological and stereological examinations. The results indicated that at day 16, there was significantly decreased CFU (Analysis of variance, p = 0.001) in the photobiomodulation + ADS (0.0 ± 0.0), ADS (1350 ± 212), and photobiomodulation (0.0 ± 0.0) groups compared with the control group (27250 ± 1284). There was significantly decreased wound area (Analysis of variance, p = 0.000) in the photobiomodulation + ADS (7.4 ± 1.4 mm²), ADS (11 ± 2.2 mm²), and photobiomodulation (11.4 ± 1.4 mm²) groups compared with the control group (25.2 ± 1.7). There was a significantly increased tensiometeric property (stress maximal load, Analysis of variance, p = 0.000) in the photobiomodulation + ADS (0.99 ± 0.06 N/cm²), ADS (0.51 ± 0.12 N/cm²), and photobiomodulation (0.35 ± 0.15 N/cm²) groups compared with the control group (0.18 ± 0.04). There was a significantly modulated inflammatory response in (Analysis of variance, p = 0.049) in the photobiomodulation + ADS (337 ± 96), ADS (1175 ± 640), and photobiomodulation (69 ± 54) treatments compared to control group (7321 ± 4099). Photobiomodulation + ADS gave significantly better improvements in CFU, wound area, and wound strength compared to photobiomodulation or ADS alone. Photobiomodulation, ADS, and their combination significantly hastened healing in ischemic methicillin-resistant Staphylococcus aureus infected delayed healing wounds in rats with DM2. Combined application of photobiomodulation plus ADS demonstrated an additive effect.

Combined effects of metformin and photobiomodulation improve the proliferation phase of wound healing in type 2 diabetic rats

We determined the impact of Photobiomodulation (PBM) and metformin administration alone and combined on the inflammation and proliferation steps of wound healing of incisions in type two diabetes mellitus (T2DM) rats. 40 rats were divided into 4 groups (n = 10 each group). A non-genetic model of T2DM was induced in all rats, and an incision was made on each rat. There were 4 groups as follows: Group 1 was control group. Group 2 received PBM alone (890 nm, 80 Hz, 0.324 J/cm², daily). Group 3 received metformin alone (50 mg/kg, i.p., daily) and the fourth group received combination of PBM + metformin. At inflammation (day 4) and proliferation (day 7) steps, tensiometerical, stereological, and immunohistochemical examinations were performed. PBM and PBM + metformin treatments significantly increased wound strength at inflammation and proliferation steps of wound healing respectively. PBM, metformin, and PBM + metformin groups significantly decreased inflammatory cells at inflammation and proliferation steps of wound healing. PBM, metformin, and PBM + metformin groups significantly improved granulation tissue formation by increasing fibroblasts, and new blood vessel formation at inflammation and proliferation steps of wound healing. Metformin significantly increased M2 macrophages than other treatment groups at inflammation and proliferation steps of wound healing. Simultaneously, PBM significantly decreased M2 macrophages than control group. We concluded PBM and PBM + metformin treatments significantly hastened repair at the inflammation and proliferation steps of repairing skin injury in a non-genetic model of T2 DM. PBM + metformin showed a synergistic impact. There were not a positive relation between M2 macrophage number and wound strength in the studied groups. The details of the molecular mechanisms of PBM, and PBM + metformin treatments of repairing wounds in animals, and treatment of DFUs of patients with T2 DM should be elucidated by further research.

Therapeutic efficacy of early photobiomodulation therapy on the zones of stasis in burns: An experimental rat model study

This study aimed to investigate the role of photobiomodulation therapy in preventing zones of stasis in burn wounds. We hypothesized that photobiomodulation therapy could promote tissue formation and release of nitric oxide (NO), and reduce inflammatory responses, thereby dilating local microvessels, reducing necrosis and apoptosis. Thirty rats were randomly divided into control group (CG) and laser group (LG). The zone of stasis was formed by applying a brass comb to the skin resulting in four rectangular burns separated by three unburned interspaces. The left side was laser wound (LW), while the right side was shielded wound (SW). The LW of LG was immediately subjected to photobiomodulation therapy, followed by once-daily 30-minutes photobiomodulation therapy sessions. Skin ultrasound and Doppler angiography analyses were used to evaluate the statuses of the zones of stasis at 1, 24, and 96 hours after injury. Harvested burn wound tissue was subjected to hematoxylin-eosin staining and HMGB1, caspase 3, and thrombomodulin immunohistochemistry, and the contents of NO and TNF-α were measured in stasis tissue. Thrombomodulin, HMGB1, and caspase 3 immunohistochemistry revealed significantly lower positive staining rates in the LW of LG rats relative to the others at 96 hours (p < 0.05), as well as a significantly higher skin blood flow relative to the others (p < 0.05). The NO content was significantly higher in the LW of LG, compared with other wounds, at 24 and 96 hours after injury (p < 0.05). The TNF-α level was significantly lower in the LW of LG than in other wounds at 96 hours (p < 0.05). Early, local photobiomodulation therapy can effectively ameliorate injury progression in the zone of stasis. However, these beneficial effects are limited to the directly irradiated sites.

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.

Low-level laser irradiation modifies the effect of hyperglycemia on adhesion molecule levels

Endothelium plays a key role in maintaining vascular homeostasis by secreting active factors involved in many biological processes such as hemostasis, angiogenesis, and inflammation. Hyperglycemia in diabetic patients causes dysfunction of endothelial cells. Soluble fractions of adhesion molecules like sE-selectin and vascular cell adhesion molecule (sVCAM) are considered as markers of endothelial damage. The low-level laser therapy (LLLT) effectively supports the conventional treatment of vascular complications in diabetes, for example hard-to-heal wounds in patients with diabetic foot syndrome. The aim of our study was to evaluate the effect of low-energy laser at the wavelength of 635 nm (visible light) and 830 nm (infrared) on the concentration of adhesion molecules: sE-selectin and sVCAM in the supernatant of endothelial cell culture of HUVEC line. Cells were cultured under high-glucose conditions of 30 mM/L. We have found an increase in sE-selectin and sVCAM levels in the supernatant of cells cultured under hyperglycemic conditions. This fact confirms detrimental influence of hyperglycemia on vascular endothelial cell cultures. LLLT can modulate the inflammation process. It leads to a decrease in sE-selectin and sVCAM concentration in the supernatant and an increase in the number of endothelial cells cultured under hyperglycemic conditions. The influence of LLLT is greater at the wavelength of 830 nm.

Cell Adhesion Molecules are Mediated by Photobiomodulation at 660 nm in Diabetic Wounded Fibroblast Cells

Diabetes affects extracellular matrix (ECM) metabolism, contributing to delayed wound healing and lower limb amputation. Application of light (photobiomodulation, PBM) has been shown to improve wound healing. This study aimed to evaluate the influence of PBM on cell adhesion molecules (CAMs) in diabetic wound healing. Isolated human skin fibroblasts were grouped into a diabetic wounded model. A diode laser at 660 nm with a fluence of 5 J/cm² was used for irradiation and cells were analysed 48 h post-irradiation. Controls consisted of sham-irradiated (0 J/cm²) cells. Real-time reverse transcription (RT) quantitative polymerase chain reaction (qPCR) was used to determine the expression of CAM-related genes. Ten genes were up-regulated in diabetic wounded cells, while 25 genes were down-regulated. Genes were related to transmembrane molecules, cell–cell adhesion, and cell–matrix adhesion, and also included genes related to other CAM molecules. PBM at 660 nm modulated gene expression of various CAMs contributing to the increased healing seen in clinical practice. There is a need for new therapies to improve diabetic wound healing. The application of PBM alongside other clinical therapies may be very beneficial in treatment.

Update on management of diabetic foot ulcers

Diabetic foot ulcers (DFUs) are a serious complication of diabetes that results in significant morbidity and mortality. Mortality rates associated with the development of a DFU are estimated to be 5% in the first 12 months, and 5-year morality rates have been estimated at 42%. The standard practices in DFU management include surgical debridement, dressings to facilitate a moist wound environment and exudate control, wound off-loading, vascular assessment, and infection and glycemic control. These practices are best coordinated by a multidisciplinary diabetic foot wound clinic. Even with this comprehensive approach, there is still room for improvement in DFU outcomes. Several adjuvant therapies have been studied to reduce DFU healing times and amputation rates. We reviewed the rationale and guidelines for current standard of care practices and reviewed the evidence for the efficacy of adjuvant agents. The adjuvant therapies reviewed include the following categories: nonsurgical debridement agents, dressings and topical agents, oxygen therapies, negative pressure wound therapy, acellular bioproducts, human growth factors, energy-based therapies, and systemic therapies. Many of these agents have been found to be beneficial in improving wound healing rates, although a large proportion of the data are small, randomized controlled trials with high risks of bias.

A randomized, open-label, controlled trial to evaluate the antimicrobial and surgical effect of CO2 laser treatment in diabetic infected foot ulcers: DULCIS (diabetic ulcer, CO2 laser, and infections) study

AIM

Debridement of fibrin and necrotic tissue from the ulcer surface is an important component of the treatment of diabetic ulcers. A possible alternative to standard lancets is represented by CO₂ laser, which vaporizes necrotic tissues together with any pathogen. The present trial is aimed at verifying the effect of a CO₂ laser on bacterial load in the debridement of infected diabetic foot ulcers.

METHODS

In this open-label randomized controlled trial (NCT02677779), patients with diabetes and an infected foot ulcers were randomized to either CO₂ laser or traditional debridement.

RESULTS

The reduction (%) of bacterial load with CO₂ laser was significantly greater than in control group [-99.9 (-100.0; -90.0) vs. -50.0 (-96.0; -75.0), p = 0.049]. Similarly, a significantly greater reduction (%) of the fraction of ulcer area covered by fibrin was obtained in the intervention group [-84.1 (-95.0; -72.2) vs. -46.9 (-69.5; -40.8), p = 0.038].

CONCLUSIONS

Debridement of ulcers with CO₂ laser significantly reduces bacterial load and fibrin-covered areas, and could be of help in the treatment of diabetic foot ulcer.

The effects of photobiomodulation therapy on Staphylococcus aureus infected surgical wounds in diabetic rats. A microbiological, histopathological, and biomechanical study

PURPOSE

To evaluate the effects of photobiomodulation therapy (PBMT) at 685 nm on diabetic wound healing in rats suffering from bacterial infection induced by Staphylococcus aureus (S. aureus).

METHODS

Thirty streptozotocin-induced diabetic rats were allocated into two groups: control and PBMT. A 4-cm full-thickness linear-incision was made on the dorsal midline and was contaminated with S. aureus. The wounds in the PBMT group were irradiated daily for 5 consecutive days, starting 3 days after the induction and always in the mornings.

RESULTS

The result revealed that PBMT resulted in a significant decrease in S. aureus CFU in the PBMT group in comparison to the control group (P<0.05). The length of wounds, in the 2nd and 3rd weeks, in the PBMT group were significantly shorter compared to the control group (P<0.05). PBMT caused a significant increase in the histological parameters in comparison to the control group (P<0.05). Moreover, PBMT significantly increased the breaking strength of the surgical scars produced in the skin of the PBMT group when compared to the control group (P<0.05).

CONCLUSION

Photobiomodulation therapy may be useful in the management of wound infection through a significant bacterial growth inhibition and an acceleration of wound healing process.

Photobiomodulation with non-thermal lasers: Mechanisms of action and therapeutic uses in dermatology and aesthetic medicine

BACKGROUND

Non-thermal laser therapy in dermatology, is a growing field in medical technology by which therapeutic effects are achieved by exposing tissues to specific wavelengths of light.

OBJECTIVES

The purpose of this review was to gain a better understanding of the science behind non-thermal laser and the evidence supporting its use in dermatology.

METHODS

A group of dermatologists and surgeons recently convened to review the evidence supporting the use of non-thermal laser for body sculpting, improving the appearance of cellulite, and treating onychomycosis.

RESULTS

The use of non-thermal laser for body sculpting is supported by three randomized, double-blind, sham-controlled studies (N = 161), one prospective open-label study (N = 54), and two retrospective studies (N = 775). Non-thermal laser application for improving the appearance of cellulite is supported by one randomized, double-blind, sham-controlled study (N = 38). The use of non-thermal laser for the treatment of onychomycosis is supported by an analysis of three non-randomized, open-label studies demonstrating clinical improvement of nails (N = 292).

CONCLUSIONS

Non-thermal laser is steadily moving into mainstream medical practice, such as dermatology. Although present studies have demonstrated the safety and efficacy of non-thermal laser for body sculpting, cellulite reduction and onychomycosis treatment, studies demonstrating the efficacy of non-thermal laser as a stand-alone procedure are still inadequate.

Effect of low-level light therapy on diabetic foot ulcers: a near-infrared spectroscopy study

Diabetic foot ulcer (DFU) is a diabetic complication due to peripheral vasculopathy and neuropathy. A promising technology for wound healing in DFU is low-level light therapy (LLLT). Despite several studies showing positive effects of LLLT on DFU, LLLT’s physiological effects have not yet been studied. The objective of this study was to investigate vascular and nervous systems modification in DFU after LLLT. Two samples of 45 DFU patients and 11 healthy controls (HCs) were recruited. The total hemoglobin (totHb) concentration change was monitored before and after LLLT by near-infrared spectroscopy and analyzed in time and frequency domains. The spectral power of the totHb changes in the very-low frequency (VLF, 20 to 60 mHz) and low frequency (LF, 60 to 140 mHz) bandwidths was calculated. Data analysis revealed a mean increase of totHb concentration after LLLT in DFU patients, but not in HC. VLF/LF ratio decreased significantly after the LLLT period in DFU patients (indicating an increased activity of the autonomic nervous system), but not in HC. Eventually, different treatment intensities in LLLT therapy showed a different response in DFU. Overall, our results demonstrate that LLLT improves blood flow and autonomic nervous system regulation in DFU and the importance of light intensity in therapeutic protocols.

Photobiomodulation (Laser and LED) on Sternotomy Healing in Hyperglycemic and Normoglycemic Patients Who Underwent Coronary Bypass Surgery with Internal Mammary Artery Grafts: A Randomized, Double-Blind Study with Follow-Up

BACKGROUND AND OBJECTIVE

This study aimed at analyzing the healing effects of low-level laser therapy (LLLT) (λ620 nm, 6 J/cm²) and light-emitting diode (LED) therapy (λ640 nm, 6 J/cm²) on the longitudinal sternotomy incisions of hyperglycemic and normoglycemic patients who underwent coronary artery bypass grafting (CABG).

MATERIALS AND METHODS

120 volunteers were electively submitted to CABG and were randomly allocated into four different groups of equal size (n = 30): control, placebo, laser (λ of 640 nm and spatial average energy fluency [SAEF] of 1.06 J/cm²), and LED (λ of 660 ± 20 nm and SAEF of 0.24 J/cm²). Laser and LED groups were irradiated from the second to eighth day postsurgery, and sternotomy incision was photographically registered. Then, participants were also separated into hyperglycemic and normoglycemic groups, according to their fasting blood glucose test before surgery. Three researchers blindly analyzed the incision photographs to determine hyperemia and wound closure at the first day of hospital discharge (eighth postoperative day).

RESULTS

LLLT and LED groups had similarly less hyperemia and less incision bleeding or dehiscence (p ≤ 0.005) and the outcomes were also analogous between hyperglycemic and normoglycemic patients, which indicates no difference observed in an intragroup analysis (p ≥ 0.05).

CONCLUSIONS

With the present therapy parameters, it may be assumed that both coherent light (laser) and non-coherent light (LED) are effective in promoting sternotomy and healing acceleration, which are evident on the eighth day postsurgery.

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.

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.