Light-emitting diodes in dermatology: A systematic review of randomized controlled trials

An Analysis of Dermatology-Related Red-Light Therapy Patient Questions on Reddit

BACKGROUND

Reddit is one of the world's most popular social media platforms and is increasingly used as a health information resource for patients on topics such as red-light (RL) therapy.

OBJECTIVE

In this article, the authors present an analysis of prevalent patient questions and concerns regarding RL therapy.

METHODS

All posts on the "Hot" page of the r/redlighttherapy subreddit were analyzed and categorized.

RESULTS

A total of 930 questions from 664 posts were analyzed. The most commonly asked question category was related to product recommendations or feedback (29.7%), followed by usage instructions (15.3%), safety and side effects (12.6%), and indications and efficacy (12.3%).

CONCLUSION

Understanding patient concerns and questions about RL, as expressed on online platforms like Reddit, can help clinicians improve patient satisfaction, education, and clinical outcomes. The study offers an innovative approach by using social media to uncover valuable patient insights that might not be easily observable within clinical settings.

Comparing the efficacy of 308-nm light-emitting diode and 308-nm excimer lamp for treating vitiligo: A randomized controlled trial

BACKGROUND

In previous studies, the 308-nm light-emitting diode (LED) has been proven safe and effective for treating vitiligo. However, direct comparisons between the 308-nm LED and 308-nm excimer lamp (308-nm MEL) for the treatment of vitiligo are lacking.

OBJECTIVE

To compare the efficacy of the 308-nm LED and 308-nm MEL for treating nonsegmental stable vitiligo.

PATIENTS AND METHODS

This randomized controlled trial was conducted between January 2018 and August 2023. Enrolled patients were randomly assigned to either the 308-nm LED or the 308-nm MEL groups, both receiving 16 treatment sessions. Adverse events that occurred during the treatment were documented.

RESULTS

In total, 269 stable vitiligo patches from 174 patients completed the study. A total of 131 lesions were included in the 308-nm LED group, and 138 lesions were included in the 308-nm MEL group. After 16 treatment sessions, 38.17% of the vitiligo patches in the 308-nm LED group achieved repigmentation of at least 50% versus 38.41% in the 308-nm MEL group. The two devices exhibited similar results in terms of efficacy for a repigmentation of at least 50% (p = .968). The incidence of adverse effects with the two phototherapy devices was comparable (p = .522).

CONCLUSIONS

Treatment of vitiligo with the 308-nm LED had a similar efficacy rate to the 308-nm MEL, and the incidence of adverse effects was comparable between the two devices.

Photobiomodulation therapy with light-emitting diode in stimulating adipose tissue mitochondria

Low-level laser therapy (LLLT) is known for its ability to induce a photochemical process, primarily targeting mitochondria, a process referred to as photobiomodulation (PBM). Recently, its use has been attributed as an adjunct in obesity treatment, to stimulate lipolysis and apoptosis. However, the pathway of stimulation remains uncertain. Thus, the objective of this study was to understand whether mitochondrial stimulation occurs in adipose tissue cells after PBM therapy, which could lead to the processes of lipolysis and apoptosis. A non-randomized clinical trial was conducted using a split abdomen design in obese women who received red and infrared LED photobiomodulation therapy (PBMT). The patients underwent bariatric surgery, and adipose tissue samples were collected for immunohistochemical analysis with primary mitochondrial antibodies. Adipose tissue samples subjected to LED intervention exhibited positivity in mitochondrial antibodies for cAMP, DRP1, FAS, FIS1, MFN2, and OPA1 (p<0.001) compared to the control group. In conclusion, we observed that PBMT was capable of generating mitochondrial stimulation in adipose tissue cells, as evidenced by the positive antibody signals. This finding suggests that mitochondrial stimulation could be the mechanism and action underlying adipose tissue lipolysis and apoptosis.

Riboflavin and Its Derivates as Potential Photosensitizers in the Photodynamic Treatment of Skin Cancers

Riboflavin, a water-soluble vitamin B2, possesses unique biological and physicochemical properties. Its photosensitizing properties make it suitable for various biological applications, such as pathogen inactivation and photodynamic therapy. However, the effectiveness of riboflavin as a photosensitizer is hindered by its degradation upon exposure to light. The review aims to highlight the significance of riboflavin and its derivatives as potential photosensitizers for use in photodynamic therapy. Additionally, a concise overview of photodynamic therapy and utilization of blue light in dermatology is provided, as well as the photochemistry and photobiophysics of riboflavin and its derivatives. Particular emphasis is given to the latest findings on the use of acetylated 3-methyltetraacetyl-riboflavin derivative (3MeTARF) in photodynamic therapy.

Opinion of speech-language pathologist on the use of photobiomodulation in the vocal clinic

PURPOSE

to investigate the opinion of Brazilian speech-language pathologists on the training, performance, and parameters used for the application of photobiomodulation (PBM) in the vocal clinic.

METHODS

observational, cross-sectional, and quantitative study, carried out through a web survey hosted on the Google Forms digital platform, composed of questions related to training, professional performance, and knowledge about PBM in the voice area. Twenty-nine speech-language pathologists of both sexes participated. Data were analyzed using descriptive statistics.

RESULTS

all participants knew the theoretical foundations of PBM, and among them, 28 (96.6%) knew its use specifically in the voice area; twenty-five respondents (86.2%) had a device to perform the irradiation, and all of them used it routinely in their clinical practice in voice. The majority (96.6%, 28) participated in a PBM training course, including specific approaches to the voice area. Participants stated that PBM is a resource that can be used in the area of ​​voice to improve performance in sung (86.2%, 25) and spoken (82.8%, 24), in addition to its application in cases of inflammatory processes in the vocal folds (79.3%, 23). As for dosimetry parameters, the most used wavelength was 808 - 830nm (37.9%, 11) and 660/808nm simultaneously (37.9%, 11), with a dose of 3-5 J per point for the patients with inflammatory processes in the vocal folds (51.7%, 15) and 6-9 J (44.8%, 13) per point for patients whose objective was improvement/conditioning.

CONCLUSION

the study participants demonstrated knowledge and training in PBM and its applicability to the voice area.

The Beneficial Role of Photobiomodulation in Neurodegenerative Diseases

Photobiomodulation (PBM), also known as Low-level Laser Therapy (LLLT), involves the use of light from a laser or light-emitting diode (LED) in the treatment of various disorders and it has recently gained increasing interest. Progressive neuronal loss with attendant consequences such as cognitive and/or motor decline characterize neurodegenerative diseases. The available therapeutic drugs have only been able to provide symptomatic relief and may also present with some side effects, thus precluding their use in treatment. Recently, there has been an exponential increase in interest and attention in the use of PBM as a therapy in various neurodegenerative diseases in animal studies. Because of the financial and social burden of neurodegenerative diseases on the sufferers and the need for the discovery of potential therapeutic inventions in their management, it is pertinent to examine the beneficial effects of PBM and the various cellular mechanisms by which it modulates neural activity. Here, we highlight the various ways by which PBM may possess beneficial effects on neural activity and has been reported in various neurodegenerative conditions (Alzheimer's disease, Parkinson's disease, epilepsy, TBI, stroke) with the hope that it may serve as an alternative therapy in the management of neurodegenerative diseases because of the biological side effects associated with drugs currently used in the treatment of neurodegenerative diseases.

Shed light on photosynthetic organisms: a physical perspective to correct light measurements

The requirements for novel and innovative production systems expedite research on light emitting diode-based illumination in a life science context. In course of these rapid developments, the scientific community is in need of a consensus regarding to the characterization and presentation of the applied lighting conditions. This publication aims to establish a basic understanding of photon physics and propose guidelines for the conclusive usage of light related quantities. To illustrate the challenges in data handling, six different light sources were measured and characterized. Furthermore, a stepwise conversion within and in-between physical systems is presented, and an opportunity to extract information from weak data sets is demonstrated. The proposed calculations indicated flexibility in data handling, but revealed partial inaccuracy for colored light emitting diodes with spectral power distribution maxima far-off 550 nm compared to spectrometer-based measurements and conversions. Furthermore, it could be shown, that when comparing light properties, the determination of photometric quantities is incorrect to describe lighting systems for photosynthetic organism and the usage of luxmeter or similar photometric sensors should be avoided. The presented guidelines shall support scientists in applying a consistent and precise characterization of their illumination regimes, tailored to their requirements to avoid ambiguous communication and the generation of incorrect and thus incomparable data based on wrong quantities and units, such as lumen or lux, in future research.

Evaluation of Photobiomodulation and Boldine as Alternative Treatment Options in Two Diabetic Retinopathy Models

Diabetic retinopathy causes progressive and irreversible damage to the retina through activation of inflammatory processes, overproduction of oxidative species, and glial reactivity, leading to changes in neuronal function and finally ischemia, edema, and hemorrhages. Current treatments are invasive and mostly applied at advanced stages, stressing the need for alternatives. To this end, we tested two unconventional and potentially complementary non-invasive treatment options: Photobiomodulation, the stimulation with near-infrared light, has shown promising results in ameliorating retinal pathologies and insults in several studies but remains controversial. Boldine, on the other hand, is a potent natural antioxidant and potentially useful to prevent free radical-induced oxidative stress. To establish a baseline, we first evaluated the effects of diabetic conditions on the retina with immunofluorescence, histological, and ultrastructural analysis in two diabetes model systems, obese LepR^db/db mice and organotypic retinal explants, and then tested the potential benefits of photobiomodulation and boldine treatment in vitro on retinal explants subjected to high glucose concentrations, mimicking diabetic conditions. Our results suggest that the principal subcellular structures affected by these conditions were mitochondria in the inner segment of photoreceptors, which displayed morphological changes in both model systems. In retinal explants, lactate metabolism, assayed as an indicator of mitochondrial function, was altered, and decreased photoreceptor viability was observed, presumably as a consequence of increased oxidative-nitrosative stress. The latter was reduced by boldine treatment in vitro, while photobiomodulation improved mitochondrial metabolism but was insufficient to prevent retinal structural damage caused by high glucose. These results warrant further research into alternative and complementary treatment options for diabetic retinopathy.

Photobiomodulation Controls Keratinocytes Inflammatory Response through Nrf2 and Reduces Langerhans Cells Activation

Photobiomodulation (PBM) is rapidly gaining traction as a valuable tool in dermatology for treating many inflammatory skin conditions using low levels of visible light or near-infrared radiation. However, the physiological regulatory pathways responsible for the anti-inflammatory effect of PBM have not been well defined. Since previous studies showed that nuclear factor-erythroid 2 like 2 (Nrf2) is a master regulator of the skin inflammatory response, we have addressed its role in controlling inflammation by PBM. Primary human keratinocytes (KCs) stimulated with 2,4-dinitrochlorobenzene (DNCB) to mimic pro-inflammatory stress were illuminated with two wavelengths: 660 nm or 520 nm. Both lights significantly reduced the mRNA expression of the DNCB-triggered TNF-α, IL-6, and IL-8 cytokines in KCs, while they enhanced Nrf2 pathway activation. PBM-induced Nrf2 is a key regulator of the inflammatory response in KCs since its absence abolished the regulatory effect of light on cytokines production. Further investigations of the mechanisms contributing to the immunoregulatory effect of PBM in inflamed human skin explants showed that 660 nm light prevented Langerhans cells migration into the dermis, preserving their dendricity, and decreased pro-inflammatory cytokine production compared to the DNCB-treated group. This study is the first to report that the PBM-mediated anti-inflammatory response in KCs is Nrf2-dependent and further support the role of PBM in skin immunomodulation. Therefore, PBM should be considered a promising alternative or complementary therapeutic approach for treating skin-related inflammatory diseases.

Comparison of the effects of 2 frequencies of application of photobiomodulation on facial rejuvenation: Controlled, randomized, and double-blind clinical trial

INTRODUCTION

Skin aging is an irreversible, slow and progressive process, mainly influenced by age, but also by external factors such as ultraviolet radiation, smoking, and alcohol, among others. It is increasingly common to look for procedures that slow down skin aging by limiting or hiding its effects on appearance. Studies have shown the benefits of photobiomodulation (PBM) for the skin, especially with the use of red light-emitting diodes. However, there is a high level of variability in the treatment parameters and frequency of application.

METHODS AND ANALYSIS

The objective of this study is to compare the effects of PBM with a light-emitting diode mask (660 nm, 6.4 mW/ cm², 8,02 J/ cm², 5.02 mW, 21 minutes) on facial rejuvenation using 2 frequency applications for 4 weeks: one group will receive PBM application on the face, twice a week and another group will receive PBM application 3 times a week. A group with simulated PBM applied twice a week for 4 weeks will be used as a control. The treatment will be performed on female participants aged between 45 and 60 years. After 4 weeks, evaluations of photographic images by specialists (Wrinkle Assessment Scale) as well as the quantitative analysis of the wrinkle size by the Image J software, the depth and width of wrinkles (assessment of face impressions by optical coherence tomography) and the level of Satisfaction with Facial Appearance Overall will be compared with data collected before the start of the study. All data will be analyzed statistically according to their distribution, seeking a level of statistical significance of 0.05.

ETHICS AND DISSEMINATION

This protocol was approved by the Research Ethics Committee of the Nove de Julho University (acceptance number: 4.365.565). This trial has been registered in ClinicalTrials.gov (ID: NCT04911140). This study is recruiting.

Photobiomodulation Reduces Periocular Wrinkle Volume by 30%: A Randomized Controlled Trial

Objective: This study aimed to evaluate red and amber light-emitting diode protocols for facial rejuvenation at the same light dose. Background: The demand for minimally invasive cosmetic procedures to address skin aging has grown throughout the world. In vitro red and amber photobiomodulation (PBM) has been shown to improve collagen synthesis. Meanwhile, red PBM has already been studied in clinical trials; however, a comparison of the use of different wavelengths at the same light dose to reduce periocular wrinkles has not yet been performed. Methods: This split-face, randomized clinical trial recruited 137 women (40-65 years old) presenting with skin phototypes II-IV and Glogau photoaging scale types II-IV. The individuals received 10 sessions for 4 weeks of red (660 nm) and amber (590 nm) PBM (3.8 J/cm²), one at each side of the face. The outcomes, measured before and after the treatments, were the periocular wrinkle volume measured by VisioFace^® RD equipment; hydration measured by the Corneometer CM 825; skin elasticity measured by the Cutometer Dual MPA 580; and quality of life determined by adapted versions of validated questionnaires [Melasma Quality of Life Scale-Brazilian Portuguese (MelasQoL-BP) and Skindex-29]. Results: There was a significant reduction in wrinkle volume after red (31.6%) and amber (29.9%) PBM. None of the treatments improved skin hydration and viscoelasticity. Both questionnaires showed improvements in participants' quality of life. Conclusions: PBM, both at red and amber wavelengths, is an effective tool for rejuvenation, producing a 30% wrinkle volume reduction. The technique has strong potential in patients with diabetes or those presenting with keloids, conditions for which highly inflammatory rejuvenating procedures are not indicated. Clinical trial registration number: REBEC-6YFCBM.

Feasibility and Safety of Using Combined Light-Emitting Diodes Versus Intense Pulsed Light Technology for the Improvement of Facial Hypervascularization in Adult Patients

Background: Superficial facial vascular lesions can be an aesthetic problem and a symptom of different skin diseases. Objective: It was to compare the efficacy and safety profiles of Dermalux^® Tri-Wave MD, based on three combined light-emitting diodes (LEDs) technology and intense pulsed light (IPL) for reducing the excess of facial vascularization due to superficial cutaneous vascular lesions. Materials and methods: The study had a single-center, proof-of-concept, open-label, and prospective design. Two groups of adult patients were treated for facial hypervascularization, LED-Group with an LED device combining 633 and 830 nm and IPL-Group with an IPL (555-950 and 530-750 nm). Variables assessed were hemoglobin hyperconcentration (HH), hemoglobin-affected area (HAA) through Antera 3D^®, and pain using the Numeric Pain Rating Scale. Results: Twenty subjects were included, 10 by group (50% female). LED-Group: Mean age 32.1 years (range, 21-46). IPL-Group: Mean age 34.5 years (range, 25-49). HH: LED-Group 100% had a moderate improvement; in the IPL-Group, 10% was moderate, and 90% was marked. HAA: LED-Group 10% had a slight improvement, 70% moderate, and 20% marked; in the IPL-Group, 100%, the improvement was marked. Seventy percent of LED-Group patients reported no pain, 30% mild; in the IPL-Group, 100% of patients reported severe pain. Conclusions: Treatment with combined red and near-infrared LEDs effectively reduced the excess of facial vascularization with moderate outcomes compared with IPL, but without secondary effects and no pain. This treatment could represent an effective, safe, and well-tolerated approach for facial vascular lesions.

Red LED light therapy associated with epidermal growth factor on wound repair process in rats

Epidermal growth factor (EGF) and light-emitting diode (LED) are currently deployed as promissory treatments for skin repair; however, the mechanisms of their association are not yet evidenced. Thus, the present study aimed to evaluate the effects of combined treatment with EGF and red LED on the wound healing processes in rats. Adult Wistar rats were randomized in control group (CG) wounds without treatment; wounds submitted to EGF treatment (EGF); wounds submitted to LED treatment (LED); wounds submitted to EGF associated with LED treatments (EGF/LED). Treatments were performed immediately after the surgical procedure and each 24 h, totaling 8 sessions. Moreover, LED was applied before EGF treatment at a single point in the center of the wound. Morphological characteristics and the immunoexpression of COX-2, VEGF, and TGF-β were measured. The results demonstrated that EGF/LED group presented a higher wound healing index. Additionally, all experimental groups presented similar findings in the histological evaluation, the degree of inflammation, and the area of dermis-like tissue. However, for EGF-treated animals (with or without LED), neoepithelial length was higher. Furthermore, all the treated groups decreased COX-2 and increased VEGF immunoexpression, and only EGF/LED group enhanced the TGF-β protein expression when compared to the untreated group. This research shows that EGF and LED modulate inflammatory process and increase the vascularity. In addition, treatment of EGF associated with LED promoted a more evident positive effect for increasing TGF-β expression and may be promising resources in the clinical treatment of cutaneous wounds.

Visible red light does not induce DNA damage in human dermal fibroblasts

Visible red light (RL) therapy is a rapidly expanding treatment option for dermatological conditions, including acne, psoriasis and chronic wounds. It is currently unknown if high fluences of RL induce DNA damage via reactive oxygen species (ROS) stress or other pathways. Our lab previously demonstrated that RL generates ROS in human dermal fibroblasts (HDFs). Other studies show that UV and blue light generate ROS and DNA damage in fibroblasts. This study aims to determine if RL induces DNA damage in HDFs. We found that 320 J/cm² , 640 J/cm² and 1280 J/cm² RL (633 ± 6 nm) did not measurably increase DNA damage in the form of cyclobutane pyrimidine dimers (CPD) or 6-4 photoproducts (6-4PP) immediately, 3 hours and 24 hours following irradiation. Our study further supports that RL therapy is safe in human skin fibroblasts.

Composite Materials Based on Polymeric Fibers Doped with Magnetic Nanoparticles: Synthesis, Properties and Applications

The increasingly sophisticated requirements of contemporary society, in relation to the assessment of environmental and health factors, are receiving much attention from the scientific community [...]

Red Light Phototherapy Using Light-Emitting Diodes Inhibits Melanoma Proliferation and Alters Tumor Microenvironments

Background

Total annual cancer rates have decreased due to improved treatment and prevention. However, the incidence of melanoma is rising, and not all patients respond to immune and targeted approaches. Therefore, we sought to determine the efficacy of red light (RL) phototherapy in preclinical models of melanoma.

Methods

Melanoma cells (A375, B16F10, MNT-1) were irradiated with RL. Melanoma proliferation, apoptosis, oxidative stress, and p53 phosphorylation were measured in vitro. In C57BL/6 mice, phototherapy safety, B16F10 tumor growth, and immunocyte infiltration were assessed following RL.

Results

In vitro, 640 J/cm² RL decreased cellular proliferation without increasing apoptosis, while 1280 J/cm² increased apoptosis. RL increased intracellular reactive oxygen species generation and p53 phosphorylation. In animal models, 2560 J/cm² RL significantly prevented melanoma growth and increased the expression of CD103+ dendritic cells. 1280 and 1920 J/cm² RL decreased tumor volume, but not significantly. RL did not cause skin inflammation or erythema in normal skin.

Conclusion

RL represents a potentially safe and effective melanoma therapeutic. RL prevented tumor growth and increased the expression of immune markers, such as CD103, that are associated with favorable melanoma outcomes. Further research is needed to determine the optimal clinical treatment regimen for melanoma using RL.

Blue Laser Irradiation Decreases the ATP Level in Mouse Skin and Increases the Production of Superoxide Anion and Hypochlorous Acid in Mouse Fibroblasts

Simple Summary

Photobiomodulation studies have reported that blue light irradiation induces the production of reactive oxygen species. We examined the effect of blue laser (405 nm) irradiation on ATP level in the skin and measured the types of reactive oxygen species and reactive nitrogen species. The decrease in the skin ATP level due to blue light irradiation may be caused by oxidative stress due to the generation of reactive oxygen species. These findings highlight the need to consider the effects on the skin when performing photobiomodulation treatment using blue light.

Abstract

Photobiomodulation studies have reported that blue light irradiation induces the production of reactive oxygen species. We investigated the effect of blue laser (405 nm) irradiation on the ATP levels in mouse skin and determined the types of reactive oxygen species and reactive nitrogen species using cultured mouse fibroblasts. Blue laser irradiation caused a decrease in the ATP level in the mouse skin and triggered the generation of superoxide anion and hypochlorous acid, whereas nitric oxide and peroxynitrite were not detected. Moreover, blue laser irradiation resulted in reduced cell viability. It is believed that the decrease in the skin ATP level due to blue light irradiation results from the increased levels of oxidative stress due to the generation of reactive oxygen species. This method of systematically measuring the levels of reactive oxygen species and reactive nitrogen species may be useful for understanding the effects of irradiation conditions.

Pigmentation and Scaring Management after Hypodermoclysis, a Case Report

Hypodermoclysis is the continuous subcutaneous infusion of a parenteral solution into dermal tissue, which is typically associated with skin lesions and cosmetic issues in the majority of patients. Scarring and pigmentation are two of the potential skin lesions after hypodermoclysis. The way skin diseases and cosmetic issues are treated has altered dramatically as a result of laser technology. This is the first article to our knowledge that describes the treatment of pigmentation and scarring produced by Hypodermoclysis cutaneous damage by using laser treatment. It was vital to select the appropriate endpoint, technology, and configuration parameters. The lesion was completely resolved after five months of treatment with four laser sessions. The first session used a fractional Er-Yag laser to perform cold ablation. The remaining sessions used 1064 and 585 nm Nd-Yag Q-switch lasers to operate in the nanosecond region. To minimize the danger of post-inflammatory hyperpigmentation (PIH), the treated region was prepped between laser treatments with 4% hydroquinone (HQ) cream. Our protocol may reduce scars and pigmentation while minimizing adverse effects and downtime.

Effect of Blue Light on Acne Vulgaris: A Systematic Review

Acne is a dermatosis that affects almost 90% of the adolescent population worldwide and its treatment is performed with retinoids, antimicrobials, acids, and topical or systemic antibiotics. Side effects such as skin irritation in addition to microbial resistance to antibiotics are the main side effects found. Phototherapy with blue light is being used as an alternative treatment. Our objective was to analyze the use of blue light to treat inflammatory acne. We conducted a systematic literature review, following the recommendation PRISMA (Preferred Reporting Items for Systematic Reviews and MetaAnalyses), including in the sample randomized clinical trial studies that compared blue light with another intervention as control. The research was carried out in the PUBMED and WEB of SCIENCE databases and the methodological quality of the studies evaluated were made by the Cochrane Collaboration Bias Risk Scale. After the exclusion of duplicates, the titles and abstracts of 81 articles were evaluated, and 50 articles were selected for full reading, including in the review at the end 8 articles. Studies have shown significant improvements in the overall picture of acne. It is concluded that despite the great potential in its use in the treatment of acne, there is a need for more detailed trials on the effect of blue light on the treatment of inflammatory acne.

HeaLED: Assessment of skin healing under light-emitting diode (LED) exposure-A randomized controlled study versus placebo

BACKGROUND

Light-emitting diodes (LEDs) in the visible or near-infrared spectrum have been reported to promote wound healing. However, despite being frequently proposed in daily clinical practice, the efficacy of photobiomodulation treatment after a laser procedure relies on very limited clinical data.

OBJECTIVE

To compare the relative efficacy of LED versus placebo treatment in decreasing erythema and transepidermal water loss (TEWL) after a fractional CO₂ session.

METHODS

We conducted an open prospective intraindividual randomized controlled study with 10 healthy volunteers. An ablative fractional laser was performed on the seven forearm areas. Three consecutive daily sessions of LED (590, 630, and 850 nm [two tested irradiances each] and placebo) were applied after randomization. Physical measures (colorimetry, TEWL), photography, and clinical evaluation were performed on Days 1, 2, 3, 7, and 21. The main criterion of evaluation was the variation of parameter a* (erythema) at 72 hours for each LED parameter compared to placebo treatment.

RESULTS

No significant differences in the variation of the parameter a* or any of the other studied parameters were found for the different LEDs compared to the placebo area.

CONCLUSION

Photobiomodulation failed to improve healing after laser ablation compared to placebo.

Effectiveness of Blue light photobiomodulation therapy in the treatment of chronic wounds. Results of the Blue Light for Ulcer Reduction (B.L.U.R.) Study

BACKGROUND

Lower limb ulcers not responding to standard treatments after 8 weeks are defined as chronic wounds, and they are a significant medical problem. Blue light (410-430 nm) proved to be effective in treating wounds, but there is a lack of data on chronic wounds in clinical practice. The study's purpose was to determine if Blue Light photobiomodulation with EmoLED medical device in addition to Standard of Care is more effective compared to Standard of care alone in promoting re-epithelialization of chronicwounds of lower limbs in 10 weeks.

METHODS

90 patients affected by multiple or large area ulcers were enrolled. To minimize all variabilities, each patient has been used as control of himself. Primary endpoint was the comparison of the re-epithelialization rate expressed as a percentage of the difference between the initial and final area. Secondary endpoints were: treatment safety, pain reduction, wound area reduction trend over time, healing rate.

RESULTS

At week 10, the wounds treated with EmoLED in addition to Standard Care showed a smaller residual wound area compared to the wounds treated with Standard of Care alone: 42.1% vs 63.4% (p=0.029). The difference is particularly evident in venous leg ulcers, 33.3% vs 60.1% (p=0.007). 17 treated wounds and 12 controls showed complete healing at week 10. Patients showed a significant reduction in pain (p = 2*10-7).

CONCLUSIONS

Blue Light treatment in addition to Standard of Care accelerates consistently the re-epithelialization rate of chronic wounds, especially venous leg ulcers and increases the chances of total wound healing in 10 weeks.

In Vitro Effect of Photodynamic Therapy with Different Lights and Combined or Uncombined with Chlorhexidine on Candida spp

Candidiasis is very common and complicated to treat in some cases due to increased resistance to antifungals. Antimicrobial photodynamic therapy (aPDT) is a promising alternative treatment. It is based on the principle that light of a specific wavelength activates a photosensitizer molecule resulting in the generation of reactive oxygen species that are able to kill pathogens. The aim here is the in vitro photoinactivation of three strains of Candida spp., Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258, using aPDT with different sources of irradiation and the photosensitizer methylene blue (MB), alone or in combination with chlorhexidine (CHX). Irradiation was carried out at a fluence of 18 J/cm² with a light-emitting diode (LED) lamp emitting in red (625 nm) or a white metal halide lamp (WMH) that emits at broad-spectrum white light (420–700 nm). After the photodynamic treatment, the antimicrobial effect is evaluated by counting colony forming units (CFU). MB-aPDT produces a 6 log₁₀ reduction in the number of CFU/100 μL of Candida spp., and the combination with CHX enhances the effect of photoinactivation (effect achieved with lower concentration of MB). Both lamps have similar efficiencies, but the WMH lamp is slightly more efficient. This work opens the doors to a possible clinical application of the combination for resistant or persistent forms of Candida infections.

Combination of an engineered Lactococcus lactis expressing CXCL12 with light-emitting diode yellow light as a treatment for scalded skin in mice

Impaired wound closure is an increasingly crucial clinical challenge. Recently, wound healing has shifted towards innovative treatments that exploit nanotechnology, biomaterials, biologics and phototherapy. Here, we constructed an engineered MG1363-pMG36e-mCXCL12 strain with pMG36e plasmid encoding stromal cell-derived factor 1α (named CXCL12) and evaluated the synergistic effects of light-emitting diode (LED) yellow light and MG1363-pMG36e-mCXCL12 on scald wounds in mice. The results indicated that the combined treatment with LED yellow light with mCXCL12 delivering strain accelerated wound closure, tissue remodelling, re-epithelialization and hair follicle regeneration and inhibited over-inflammation oppositely in the central and surrounding wounds by macroscopic, histopathologic and immunohistochemistry parameters. Furthermore, combination therapy increased the epidermal growth factor and Ki67-positive cells and upregulated beta-catenin (β-catenin), cellular-myelocytomatosis (c-Myc), wingless-type MMTV integration site family member 1 (Wnt1), Jagged 1, neurogenic locus notch homolog protein 1 (Notch 1) and hairy and enhancer of split 1 (Hes 1) protein levels of the Wnt and Notch signalling pathways. It also facilitated collagen fibrogenesis and deposition and improved the activities of hydroxyproline, superoxide dismutase and glutathione peroxidase in scalded granulation tissue, in addition to reducing the inflammatory factors interleukin 1 beta (IL-1β) and tumour necrosis factor alpha (TNF-α). The combined treatment effectively reduced skin pathogens Ralstonia and Acinetobacter to further reduce the risk of infection. Overall, combination of LED yellow light and MG1363-pMG36e-mCXCL12 represents a potential strategy for the treatment of cutaneous wounds.

Light emitting diode-red light for reduction of post-surgical scarring: Results from a dose-ranging, split-face, randomized controlled trial

Scarring has significant esthetic and functional consequences for patients. A need exists for anti-scarring therapeutics. Light emitting diode-red light (LED-RL) has been shown to modulate skin fibrosis. The aim of this study is to evaluate the safety and efficacy of LED-RL to reduce post-operative scarring. Cutaneous Understanding of Red-light Efficacy on Scarring was a randomized, mock-controlled, single-blind, dose-ranging, split-face phase II clinical trial. Starting 1 week post-surgery, patients received LED-RL irradiation and temperature-controlled mock therapy to incision sites at fluences of 160, 320 or 480 J/cm2 , triweekly for 3 weeks. Efficacy was assessed at 1, 3 and 6-12 months. The primary endpoint was difference in scar pliability between LED-RL-treated and control sites. Secondary outcomes included Patient and Observer Scar Assessment Scale, collagen and water concentration, and adverse events. There were no significant differences in scar pliability between treated and control scars. At certain fluences, treated scars showed greater improvements in observer rating and scar pliability, reflected by greater reductions in induration, from baseline to 6 months compared to control scars. Treatment-site adverse events included blistering (n = 2) and swelling (n = 1), which were mild and resolved without sequelae. LED-RL phototherapy is safe in the early postoperative period and may reduce scarring.

Visible light. Part I: Properties and cutaneous effects of visible light

Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and flash lamps. Photons from visible light are absorbed by photoreceptive chromophores (e.g., melanin, heme, and opsins), altering skin function by activating and imparting energy to chromophores. Additionally, visible light can penetrate the full thickness of the skin and induce pigmentation and erythema. Clinically, lasers and light devices are used to treat skin conditions by utilizing specific wavelengths and treatment parameters. Red and blue light from light-emitting diodes and intense pulsed light have been studied as antimicrobial and anti-inflammatory treatments for acne. Pulsed dye lasers are used to treat vascular lesions in adults and infants. Further research is necessary to determine the functional significance of visible light on skin health without confounding the influence of ultraviolet and infrared wavelengths.

Photobiomodulation of Human Fibroblasts and Keratinocytes with Blue Light: Implications in Wound Healing

In recent years, photobiomodulation (PBM) has been recognized as a physical therapy in wound management. Despite several published research papers, the mechanism underlying photobiomodulation is still not completely understood. The investigation about application of blue light to improve wound healing is a relatively new research area. Tests in selected patients evidenced a stimulation of the healing process in superficial and chronic wounds treated with a blue LED light emitting at 420 nm; a study in animal model pointed out a faster healing process in superficial wound, with an important role of fibroblasts and myofibroblasts. Here, we present a study aiming at evidencing the effects of blue light on the proliferation and metabolism in fibroblasts from healthy skin and keratinocytes. Different light doses (3.43, 6.87, 13.7, 20.6, 30.9 and 41.2 J/cm2) were used to treat the cells, evidencing inhibitory and stimulatory effects following a biphasic dose behavior. Electrophysiology was used to investigate the effects on membrane currents: healthy fibroblasts and keratinocytes showed no significant differences between treated and not treated cells. Raman spectroscopy revealed the mitochondrial Cytochrome C (Cyt C) oxidase dependence on blue light irradiation: a significant decrease in peak intensity of healthy fibroblast was evidenced, while it is less pronounced in keratinocytes. In conclusion, we observed that the blue LED light can be used to modulate metabolism and proliferation of human fibroblasts, and the effects in wound healing are particularly evident when studying the fibroblasts and keratinocytes co-cultures.

On-demand and tunable dual wavelength release of antibody using light-responsive hydrogels

There has been an increased interest in the use of protein therapeutics, especially antibodies, for the treatment of a variety of diseases due to their high specificity to tissues and biological pathways of interest. However, the use of antibodies can be hindered by physical aggregation, degradation, and diffusion when injected in vivo leading to the need for antibody-releasing depots for the controlled and localized delivery within tissues of interest. Here, we investigated photolabile hydrogel chemistries for creating on-demand and tunable antibody release profiles. Innovative, scalable synthetic procedures were established and applied for fabricating hydrogels with nitrobenzyl (NB) and coumarin (CMR) photolabile crosslinks that responded to clinically relevant doses of long-wavelength UV and short-wavelength visible light. This synthetic procedure includes a route to make a CMR linker possessing two functional handles at the same ring position with water-stable bonds. The photocleavage properties of NB and CMR crosslinked hydrogels were characterized, as well as their potential for translational studies by degradation through pig skin, a good human skin mimic. The mechanism of hydrogel degradation, bulk versus surface eroding, was determined to be dependent on the wavelength of light utilized and the molar absorptivity of the different photolabile linkers, providing a facile means for altering protein release upon hydrogel degradation. Further, the encapsulation and on-demand release of a model monoclonal antibody was demonstrated, highlighting the ability to control antibody release from these hydrogels through the application of light while retaining its bioactivity. In particular, the newly designed CMR hydrogels undergo surface erosion-based protein release using visible light, which is more commonly used clinically. Overall, this work establishes scalable syntheses and relevant pairings of formulation-irradiation conditions for designing on-demand and light-responsive material systems that provide controlled, tunable release of bioactive proteins toward addressing barriers to preclinical translation of light-based materials and ultimately improving therapeutic regimens.

Low-level light therapy using a helmet-type device for the treatment of androgenetic alopecia: A 16-week, multicenter, randomized, double-blind, sham device-controlled trial

INTRODUCTION

Androgenetic alopecia is the most common form of hair loss in both sexes. In recent studies, low-level light therapy (LLLT) has been established as an effective treatment for alopecia. The purpose of this study was to evaluate the safety and efficacy of LLLT using a new helmet-type device for the treatment of androgenetic alopecia.

METHOD

A randomized, sham device-controlled, double-blind clinical trial was conducted at 2 institutions. Sixty participants diagnosed with androgenetic alopecia aged from 19 to 65 years were recruited. LLLT was performed through a helmet-type device that emitted light with a mean output power of 2.36 mW/cm at a wavelength of 655 nm. Participants were divided into 2 groups, which respectively used the experimental device and a sham device. After tattooing at the central point of the vertex, phototrichograms at that point were obtained at 0, 8, and 16 weeks. The primary endpoint of the study was the difference in the rate of change of hair density between the test group and the control group.

RESULTS

Comparing the results at baseline and week 16, the experimental group showed an increase in hair density of 41.90 hairs/cm and an increase in hair thickness of 7.50 μm, whereas the control group showed an increase of 0.72 hairs/cm and a decrease of 15.03 μm, respectively (P < .001). No adverse events or side effects occurred.

CONCLUSION

LLLT showed a significant effect on increasing hair density in patients with androgenetic alopecia. LLLT could be a safe and effective treatment for androgenetic alopecia in both sexes.

Comparison of ophthalmic toxicity of light-emitting diode and organic light-emitting diode light sources

The use of organic light-emitting diodes (OLEDs) has rapidly increased in recent years. However, the effect of OLEDs on human health has not been studied yet. We investigated morphologic and functional changes after OLEDs exposure of human ocular cells, including corneal, conjunctival, lens, and retinal pigment epithelial cells, and mouse eyes. In corneal and conjunctival epithelial cells, the levels of reactive oxygen species production and interleukin-8 expression after white light-emitting diodes (LED) exposure were significantly greater than those after OLED exposure. Although no gross morphologic changes of the eyelid or cornea were found in LED- or OLED-exposed mice, oxidative stress on ocular surface was significantly increased, and the outer nuclear layer (ONL) was significantly shorter in both light-treated groups than the control group. Moreover, ONL thickness was significantly lower in the LED group than the OLED group. The electroretinography response was significantly lower in light exposure group, and there was significant difference between LED- and OLED-treated mice. Although OLED exhibits certain ocular toxicity, it can be less toxic to eyes than LED. The higher blue-wavelength energy of LED light might be the reason for its higher toxicity relative to OLED.

Safety of light emitting diode-red light on human skin: Two randomized controlled trials

Therapeutic applications of light emitting diode-red light (LED-RL) are expanding, yet data on its clinical effects are lacking. Our goal was to evaluate the safety of high fluence LED-RL (≥160 J/cm2 ). In two phase I, single-blind, dose escalation, randomized controlled trials, healthy subjects received LED-RL or mock irradiation to the forearm thrice weekly for 3 weeks at fluences of 160-640 J/cm2 for all skin types (STARS 1, n = 60) and at 480-640 J/cm2 for non-Hispanic Caucasians (STARS 2, n = 55). The primary outcome was the incidence of adverse events (AEs). The maximum tolerated dose was the highest fluence that did not elicit predefined AEs. Dose-limiting AEs, including blistering and prolonged erythema, occurred at 480 J/cm2 in STARS 1 (n = 1) and 640 J/cm2 in STARS 2 (n = 2). AEs of transient erythema and hyperpigmentation were mild. No serious AEs occurred. We determined that LED-RL is safe up to 320 J/cm2 for skin of color and 480 J/cm2 for non-Hispanic Caucasian individuals. LED-RL may exert differential cutaneous effects depending on race and ethnicity, with darker skin being more photosensitive. These findings may guide future studies to evaluate the efficacy of LED-RL for the treatment of various diseases.

Irradiation with Polychromatic Incoherent Low Energy Radiation of Human Peripheral Blood Mononuclear Cells In Vitro: Effects on Cytokine Production

(1) Background: Physical stimuli may activate peripheral blood mononuclear cells (PBMCs) to secrete cytokines, which may favor pro-inflammatory responses or trigger reparative phenomena. The purpose of this study is to evaluate the action of Polarized Polychromatic Incoherent Low Energy Radiation (PILER) on human in vitro PBMCs, by detection of the possible effects on cytokine production; (2) Methods: isolated PBMCs were irradiated with a PILER lamp at different exposure times, at a distance of 10 cm, before incubation. The supernatants were collected after 24 h and 48 h and cytokines evaluated by ELISA; (3) Results: Our results showed a decrease in the levels of pro-inflammatory IL-12p70, IL-17A, IFN-γ, and TNF-α cytokines, whereas IL-10 and TGF-β1 with regulatory activity increased; (4) Conclusions: PILER irradiation affected the cytokine production by isolated PBMCs driving the immune response toward an anti-inflammatory/reparative profile.

A dose-ranging, parallel group, split-face, single-blind phase II study of light emitting diode-red light (LED-RL) for skin scarring prevention: study protocol for a randomized controlled trial

BACKGROUND

Skin fibrosis is a significant global health problem that affects over 100 million people annually and has a profoundly negative impact on quality of life. Characterized by excessive fibroblast proliferation and collagen deposition, skin fibrosis underlies a wide spectrum of dermatologic conditions ranging from pathologic scars secondary to injury (e.g., burns, surgery, trauma) to immune-mediated diseases. Effective anti-scarring therapeutics remain an unmet need, underscoring the importance of developing novel approaches to treat and prevent skin fibrosis. Our in vitro data show that light emitting diode-red light (LED-RL) can modulate key cellular and molecular processes involved in skin fibrosis. In two phase I clinical trials (STARS 1 and STARS 2), we demonstrated the safety and tolerability of LED-RL at fluences of 160 J/cm² up to 480 J/cm² on normal human skin.

METHODS/DESIGN

CURES (Cutaneous Understanding of Red-light Efficacy on Scarring) is a dose-ranging, randomized, parallel group, split-face, single-blind, mock-controlled phase II study to evaluate the efficacy of LED-RL to limit post-surgical skin fibrosis in subjects undergoing elective mini-facelift surgery. Thirty subjects will be randomly allocated to three treatment groups to receive LED-RL phototherapy or temperature-matched mock irradiation (control) to either periauricular incision site at fluences of 160 J/cm², 320 J/cm², or 480 J/cm². Starting one week post-surgery (postoperative days 4-8), treatments will be administered three times weekly for three consecutive weeks, followed by efficacy assessments at 30 days, 3 months, and 6 months. The primary endpoint is the difference in scar pliability between LED-RL-treated and control sites as determined by skin elasticity and induration measurements. Secondary outcomes include clinical and photographic evaluations of scars, 3D skin imaging analysis, histological and molecular analyses, and adverse events.

DISCUSSION

LED-RL is a therapeutic modality of increasing importance in dermatology, and has the potential to limit skin fibrosis clinically by decreasing dermal fibroblast activity and collagen production. The administration of LED-RL phototherapy in the early postoperative period may optimize wound healing and prevent excessive scarring. The results from this study may change the current treatment paradigm for fibrotic skin diseases and help to pioneer LED-RL as a safe, non-invasive, cost-effective, portable, at-home therapy for scars.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03795116 . Registered on 20 December 2018.

Photo-controlled delivery of a potent analogue of doxorubicin

Highly cytotoxic agents have found an important niche in targeted anticancer therapy. Here we develop a new light release strategy for the targeting of one of these agents, 2-pyrrolinodoxorubicin, showing dramatic enhancements in toxicity with light and single digit nM potency.

FLUORESCENT LIGHT ENERGY: The Future for Treating Inflammatory Skin Conditions?

Background: We have previously reported clinical efficacy with a novel form of photobiomodulation-a biophotonic platform inducing fluorescent light energy (FLE)-in both disease-affected and healthy skin; however, the cellular mechanisms remain largely unknown. Objective: This study investigated the cellular mechanism of action of FLE on key skin and immune cells. Methods: We examined the effects of FLE on the clinical presentation of inflammation in a representative patient with acne vulgaris. The effect of FLE and an FLE-mimicking control lamp on collagen production from primary human dermal fibroblast (HDF) cells was assessed in the presence and absence of the proinflammatory cytokine, interferon gamma (IFN-γ). Cytokine production was assessed from HDF and human epidermal keratinocytes (HEK) exposed to M1 macrophage-conditioned media following illumination with either a blue light-emitting diode (LED) or FLE. Finally, the effects of FLE on angiogenesis were assessed in human aortic endothelial (HAE) cells. Results: FLE reduced inflammatory lesions and associated redness in the representative acne patient. Following the resolution of inflammation there was an overall enhancement of the skin's texture. FLE enhanced collagen production from nonstressed HDF cells, decreased the inflammatory profile of HDF and HEK cells, and enhanced angiogenesis in HAE cells. Conclusion: Our results suggest FLE is capable of enhancing collagen production, modulating cutaneous inflammation, and encouraging angiogenesis. While further research is required, our findings have important implications for approaches to treating inflammatory skin conditions and achieving better aesthetic outcomes.

MicroRNA expression analysis of human skin fibroblasts treated with high-fluence light-emitting diode-red light

Skin fibrosis is a chronic debilitating feature of several skin diseases that lead to characteristic increases in dermal fibroblast proliferation and collagen deposition through upregulation in components of the transforming growth factor beta (TGF-B)/SMAD pathway. In contrast to ultraviolet phototherapy, high-fluence light-emitting diode-generated red light (HF-LED-RL, 633 ± 15 nm) is a safe, economic and non-invasive therapy with in vitro evidence that supports modulation of the key cellular characteristics involved in the pathogenesis of skin fibrosis. Limited data exists pertaining to the effects of HF-LED-RL on human skin fibroblast microRNA (miRNA). Herein, we explored the effects of HF-LED-RL on fibroblast miRNA levels using RNA-seq and miRNA expression analysis. Using RNA-seq analysis we found that HF-LED-RL at 320 and 640 J/cm² increased transcription of key miRNA that are involved in skin fibrosis including miRNA-29, miRNA-196a and Let-7a, and decreased transcription of miRNA-21, miRNA-23b and miRNA-31. These microRNA findings provide insight into the molecular underpinnings of HF-LED-RL and highlight potential therapeutic targets of interest for the treatment of skin fibrosis. Additional research on the specific molecular mechanisms underlying HF-LED-RL effects on fibroblasts may provide further mechanistic insight into this therapy and may reveal additional future therapeutic targets for skin fibrosis.

A single-blind, dose-escalation, phase I study of high-fluence light-emitting diode-red light on Caucasian non-Hispanic skin: study protocol for a randomized controlled trial

BACKGROUND

Visible light (400 to 700 nm) is common in our environment, comprising 44% of total solar radiation and a large component of environmental light exposure. The effects of visible light on skin remain undefined. The red light portion of the visible spectrum (600 to 700 nm) may be used to treat skin diseases as a monotherapeutic modality or in combination with other agents. Light-emitting diode-red light (LED-RL) phototherapy may represent an important advance in light-based treatment modalities because it is non-invasive, inexpensive, portable, and easily combinable with other therapies. We previously determined the maximum tolerated dose (MTD) of high-fluence LED-RL (HF-LED-RL) in skin of color individuals to be 320 J/cm2. To the best of our knowledge, no clinical trials have been performed to determine the safety of higher doses of HF-LED-RL in Caucasian non-Hispanic individuals. The aim of this study is to investigate the safety of HF-LED-RL at doses of 480 and 640 J/cm2 in healthy Caucasian non-Hispanic individuals.

METHODS

This is a single-blind, dose-escalation, randomized, controlled, phase I trial titled Safety Trial Assessing Red-light on Skin (STARS) 2. Healthy subjects will be randomly assigned to groups of five (three subjects randomly assigned to HF-LED-RL phototherapy and two subjects randomly assigned to mock therapy). Subjects in group 1 will receive HF-LED-RL or mock irradiation at the starting dose of 480 J/cm2, and the dose will be escalated in the subsequent group (group 2) to 640 J/cm2. The MTD is defined as the dose level below the dose at which two or more subjects (>20% of the cohort) experience a dose-limiting toxicity (DLT). After either the MTD is established or the study endpoint of 640 J/cm2 is achieved, additional HF-LED-RL phototherapy subjects and mock therapy subjects will be enrolled at that fluence (group 3) for a total number of up to 60 subjects. Each subject will receive a total of nine irradiation sessions, three times per week for three consecutive weeks.

DISCUSSION

This follow-up study aims to provide important knowledge about safety and cutaneous effects of HF-LED-RL phototherapy of 480 and 640 J/cm2 in Caucasian non-Hispanic subjects. The importance of this clinical trial is that it may establish new treatment paradigms and a safety profile for LED-RL based on race and ethnicity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03433222 . Registered on February 1, 2018 - Retrospectively registered. Protocol date and version: January 12, 2018; version 1.

Patient-reported outcomes in lasers and light therapy

As the prevalence of lasers and light devices to treat dermatologic conditions increases, patient reported outcomes (PROs) will be an essential component of evaluating clinical efficacy and patient satisfaction. PROs may be used to identify patients' values, weigh risks and benefits of various therapies, identify barriers to treatment and help guide the development of new therapies. Utilizing patient and physician assessments may help determine if a new treatment is objectively better than currently available therapies. In creating a patient-centered treatment plan using laser and light modalities, it is critical to evaluate side effects using PROs. Determining and resolving barriers to treatment has benefits at the individual level and the population level. Many PRO measures (PROMs) are available to use for general and specific dermatologic conditions. The Dermatologic Life Quality Index, Skindex, and FACE-Q are PROMs that have been used in laser and light therapy studies. Selecting the proper instrument should be based on study aims to yield high quality data. Herein, we assess PROs use in laser and light treatment protocols to improve patient care, increase patient satisfaction and reduce barriers to care, and review dermatology PRO measures (PROMs) used in published laser and light clinical studies.

Trichogenic Photostimulation Using Monolithic Flexible Vertical AlGaInP Light-Emitting Diodes

Alopecia is considered an aesthetic, psychological, and social issue among modern people. Although laser-induced skin stimulation is utilized for depilation treatment, such treatment has significant drawbacks of high energy consumption, huge equipment size, and limited usage in daily life. Here, we present a wearable photostimulator for hair-growth applications using high-performance flexible red vertical light-emitting diodes (f-VLEDs). Flexible microscale LEDs were effectively fabricated by a simple monolithic fabrication process, resulting in high light output (∼30 mW mm^-2), low forward voltage (∼2.8 V), and excellent flexibility for wearable biostimulation. Finally, trichogenic stimulation of a hairless mouse was achieved using high-performance red f-VLEDs with high thermal stability, device uniformity, and mechanical durability.

Photodynamic and photobiological effects of light-emitting diode (LED) therapy in dermatological disease: an update

Benefit deriving from the use of light is known since ancient time, but, only in the last decades of twentieth century, we witnessed the rapid expansion of knowledge and techniques. Light-emitted diode (LED)-based devices represent the emerging and safest tool for the treatment of many conditions such as skin inflammatory conditions, aging, and disorders linked to hair growth. The present work reviews the current knowledge about LED-based therapeutic approaches in different skin and hair disorders. LED therapy represents the emerging and safest tool for the treatment of many conditions such as skin inflammatory conditions, aging, and disorders linked to hair growth. The use of LED in the treatment of such conditions has now entered common practice among dermatologists. Additional controlled studies are still needed to corroborate the efficacy of such kind of treatment.

Efficacy of phototherapy to treat facial ageing when using a red versus an amber LED: a protocol for a randomised controlled trial

INTRODUCTION

The skin undergoes morphological and physiological changes with the advancing age of an individual. These changes may be caused by intrinsic and extrinsic factors that contribute to cellular ageing and consequent skin ageing. The term photoageing is used to characterise the ageing of the skin caused by solar radiation. Clinically, the skin becomes more flaccid, thicker and hyperpigmented, while there is an early appearance of wrinkles and other skin changes, such as skin cancer. Nowadays, there are numerous treatments for ageing skin, and one of them is with the use of phototherapy, which uses light-emitting diodes (LEDs). The objective of this study will be to evaluate the percentages of reduction in the volume of periocular wrinkles when treated with red and amber LEDs.

METHODS AND ANALYSIS

All of the participants will receive photobiomodulation to treat their periocular wrinkles. They will be using red and amber LEDs, with one colour being used on each hemiface. The facial side to be treated with each colour will be randomised. After an interval of 180 days, the participants will receive a cross-treatment. The primary variable of the study is the volume of periocular wrinkles (crow's feet), which will be measured by a VisioFace equipment. The secondary variables are elasticity (measured by Cutometer) and hydration (measured by Corneometer). Quality of life and self-assessment of the participants will be measured using the adapted Melasma Quality of Life scale - Brazilian Portuguese adaption (MelasQoL-BP) and Skindex-29 questionnaires. All of the variables will be measured before and after a group of 10 sessions.

ETHICS AND DISSEMINATION

This protocol was approved by the Research Ethics Committee of the Nove de Julho University (acceptance number: 2.550.732). This trial has been registered in the Registro Brasileiro de Ensaios Clínicos (Brazilian Clinical Trials Registry) (REBEC number: RBR-6YFCBM). This study is not recruiting yet.

TRIAL REGISTRATION NUMBER

RBR6YFCBM; Pre-results.

How UV Light Touches the Brain and Endocrine System Through Skin, and Why

The skin, a self-regulating protective barrier organ, is empowered with sensory and computing capabilities to counteract the environmental stressors to maintain and restore disrupted cutaneous homeostasis. These complex functions are coordinated by a cutaneous neuro-endocrine system that also communicates in a bidirectional fashion with the central nervous, endocrine, and immune systems, all acting in concert to control body homeostasis. Although UV energy has played an important role in the origin and evolution of life, UV absorption by the skin not only triggers mechanisms that defend skin integrity and regulate global homeostasis but also induces skin pathology (e.g., cancer, aging, autoimmune responses). These effects are secondary to the transduction of UV electromagnetic energy into chemical, hormonal, and neural signals, defined by the nature of the chromophores and tissue compartments receiving specific UV wavelength. UV radiation can upregulate local neuroendocrine axes, with UVB being markedly more efficient than UVA. The locally induced cytokines, corticotropin-releasing hormone, urocortins, proopiomelanocortin-peptides, enkephalins, or others can be released into circulation to exert systemic effects, including activation of the central hypothalamic-pituitary-adrenal axis, opioidogenic effects, and immunosuppression, independent of vitamin D synthesis. Similar effects are seen after exposure of the eyes and skin to UV, through which UVB activates hypothalamic paraventricular and arcuate nuclei and exerts very rapid stimulatory effects on the brain. Thus, UV touches the brain and central neuroendocrine system to reset body homeostasis. This invites multiple therapeutic applications of UV radiation, for example, in the management of autoimmune and mood disorders, addiction, and obesity.

Differential response of human dermal fibroblast subpopulations to visible and near-infrared light: Potential of photobiomodulation for addressing cutaneous conditions

BACKGROUND OBJECTIVES

The past decade has witnessed a rapid expansion of photobiomodulation (PBM), demonstrating encouraging results for the treatment of cutaneous disorders. Confidence in this approach, however, is impaired not only by a lack of understanding of the light-triggered molecular cascades but also by the significant inconsistency in published experimental outcomes, design of the studies and applied optical parameters. This study aimed at characterizing the response of human dermal fibroblast subpopulations to visible and near-infrared (NIR) light in an attempt to identify the optical treatment parameters with high potential to address deficits in aging skin and non-healing chronic wounds.

MATERIALS AND METHODS

Primary human reticular and papillary dermal fibroblasts (DF) were isolated from the surplus of post-surgery human facial skin. An in-house developed LED-based device was used to irradiate cell cultures using six discrete wavelengths (450, 490, 550, 590, 650, and 850 nm). Light dose-response at a standard oxygen concentration (20%) at all six wavelengths was evaluated in terms of cell metabolic activity. This was followed by an analysis of the transcriptome and procollagen I production at a protein level, where cells were cultured in conditions closer to in vivo at 2% environmental oxygen and 2% serum. Furthermore, the production of reactive oxygen species (ROS) was accessed using real-time fluorescence confocal microscopy imaging. Here, production of ROS in the presence or absence of antioxidants, as well as the cellular localization of ROS, was evaluated.

RESULTS

In terms of metabolic activity, consecutive irradiation with short-wavelength light (⇐530 nm) exerted an inhibitory effect on DF, while longer wavelengths (>=590 nm) had essentially a neutral effect. Cell behavior following treatment with 450 nm was biphasic with two distinct states: inhibitory at low- to mid- dose levels (<=30 J/cm² ), and cytotoxic at higher dose levels (>30 J/cm² ). Cell response to blue light was accompanied by a dose-dependent release of ROS that was localized in the perinuclear area close to mitochondria, which was attenuated by an antioxidant. Overall, reticular DFs exhibited a greater sensitivity to light treatment at the level of gene expression than did papillary DFs, with more genes significantly up- or down- regulated. At the intra-cellular signaling pathway level, the up- or down- regulation of vital pathways was observed only for reticular DF, after treatment with 30 J/cm² of blue light. At the cellular level, short visible wavelengths exerted a greater inhibitory effect on reticular DF. Several genes involved in the TGF-β signaling pathway were also affected. In addition, procollagen I production was inhibited. By contrast, 850 nm near-infrared (NIR) light (20 J/cm² ) exerted a stimulatory metabolic effect in these cells, with no detectable intracellular ROS formation. Here too, reticular DF were more responsive than papillary DF. This stimulatory effect was only observed under in vivo-like low oxygen conditions, corresponding to normal dermal tissue oxygen levels (approximately 2%).

CONCLUSION

This study highlights a differential impact of light on human skin cells with upregulation of metabolic activity with NIR light, and inhibition of pro-collagen production and proliferation in response to blue light. These findings open-up new avenues for developing therapies for different cutaneous conditions (e.g., treatment of keloids and fibrosis) or differential therapy at distinct stages of wound healing. Lasers Surg. Med. 50:859-882, 2018. © 2018 Wiley Periodicals, Inc.