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

Effects of photobiomodulation on human hair dermal papilla cells with various light modes and light parameters

Androgenetic alopecia (AGA) is a prevalent hair loss disorder and influenced by genetic, hormonal, and environmental factors. Minoxidil and finasteride have been widely used for treating AGA. However, the side effects associated with these drugs often lead to poor patient compliance. In contrast, photobiomodulation (PBM), due to its safety and non-invasiveness, holds promising prospects for use. Although the promoting effects of PBM on AGA have been reported, the mechanisms by which PBM affects dermal papilla cells (DPCs) remain largely unknown. Hence, this study explored the impacts of both continuous wave (CW) and pulsed wave (PW) PBM on DPCs, and revealed the underlying actions of light parameters in PBM. Orthogonal experiments were conducted to evaluate the effects of CW PBM on DPCs at varying irradiances and doses, indicating that irradiance was the crucial parameter, as well as cell viability and proliferation were maximized at 8 mW/cm2 and 8 J/cm2. For PW PBM, response surface methodology was employed to determine the influences of duty cycles, frequencies, and doses. The findings highlighted frequency as a primary factor, with the optimum cell viability observed at peak irradiance 10 mW/cm2, duty cycle 80 %, 500 Hz, and 8.8 J/cm2. Notably, PBM could enhance cell viability, proliferation, and migration in DPCs by activating the Wnt/β-Catenin signaling and suppressing Transforming Growth Factor signaling, particularly when applied in pulsed mode. Overall, this study determined the key light parameters that influence PBM effectiveness, further identified the optimal light conditions, and preliminary revealed into the mechanisms of PBM in DPCs, highlighting that PW PBM may be a competitive therapeutic option for alleviating AGA in the future.

Ultrasound-assisted laser therapy for selective removal of melanoma cells

The current study explores the potential of ultrasound-assisted laser therapy (USaLT) to selectively destroy melanoma cells. The technology was tested on an ex vivo melanoma model, which was established by growing melanoma cells in chicken breast tissue. Ultrasound-only and laser-only treatments were used as control groups. USaLT was able to effectively destroy melanoma cells and selectively remove 66.41% of melanoma cells in the ex vivo tumor model when an ultrasound peak negative pressure of 2 MPa was concurrently applied with a laser fluence of 28 mJ/cm2 at 532 nm optical wavelength for 5 min. The therapeutic efficiency was further improved with the use of a higher laser fluence, and the treatment depth was improved to 3.5 mm with the use of 1,064 nm laser light at a fluence of 150 mJ/cm2. None of the laser-only and ultrasound-only treatments were able to remove any melanoma cells. The treatment outcome was validated with histological analyses and photoacoustic imaging. This study opens the possibility of USaLT for melanoma that is currently treated by laser therapy, but at a much lower laser fluence level, hence improving the safety potential of laser therapy.

Meta-stable state photoacid containing β-estradiol fragment with photomodulated biological activity and anti-cancer stem cells properties

Photopharmacology is a young and rapidly developing field of research that offers significant potential for new insights into targeted therapy. While it primarily focuses on cancer treatment, it also holds promise for other diseases. The key feature of photopharmacological agents is the presence of a photosensitive and biologically active component in the same molecule. In our current study, we synthesized a spiropyran-based meta-stable state photoacid containing a fragment of β-estradiol. This compound exhibits negative photochromism and photocontrolled fluorescence under visible-light irradiation due to the initial stabilization of its self-protonated form in solution. We conducted comprehensive biological studies on the HeLa cells model to assess the short- and long-term cytotoxicity of the photoacid, its metabolic effects, its influence on signaling and epithelial-mesenchymal transition super-system pathways, and the proportion of the population enriched with cancer stem cells. Our findings reveal that this derivative demonstrates low cytotoxicity to HeLa cells, yet it is capable of dramatically reducing malignant cells side population enriched in cancer stem cells. Additionally, appropriate structural modification lead to an increase in some other biological effects compared to β-estradiol. In particular, our substance possesses rare properties of AP-1 suppression and demonstrates some pro-oxidant and metabolic effects, which can be regulated by visible light irradiation. As a result, the new estradiol-based photoacid may be considered a promising multi-acting photopharmacological agent for the next-generation anti-cancer research & development.

Near-infrared light does not induce DNA damage in human dermal fibroblasts

Photobiomodulation (PBM) can be used to treat a range of conditions in dermatology. PBM refers to the changes induced by red (RL, 620-700 nm) and near-infrared (NIR, 700-1440 nm) light. Light radiation-induced DNA damage is a major contributor to aging and skin cancer. It is crucial to study the effects of PBM on DNA to ensure safety. Our lab previously demonstrated that RL (633 ± 6 nm) did not result in human dermal fibroblasts (HDFs) DNA damage. This study employed similar methods to investigate NIR effects. Commercially available LED-NIR (830 ± 5 nm) panels (66, 132, and 264 J/cm2 ) did not result in DNA damage measured by cyclobutane pyrimidine dimers and pyrimidine-6,4-pyrimidone photoproducts in HDFs compared to temperature-matched controls immediately, 3 h, and 24 h following irradiation and compared to positive and negative controls. This demonstrates that LED-NIR does not damage DNA in HDFs in vitro.

Newly Synthesized CoFe2-xDyxO4 (x = 0; 0.1; 0.2; 0.4) Nanoparticles Reveal Promising Anticancer Activity against Melanoma (A375) and Breast Cancer (MCF-7) Cells

The current study focuses on the synthesis via combustion of dysprosium-doped cobalt ferrites that were subsequently physicochemically analyzed in terms of morphological and magnetic properties. Three types of doped nanoparticles were prepared containing different Dy substitutions and coated with HPGCD for higher dispersion properties and biocompatibility, and were later submitted to biological tests in order to reveal their potential anticancer utility. Experimental data obtained through FTIR, XRD, SEM and TEM confirmed the inclusion of Dy3+ ions in the nanoparticles' structure. The size of the newly formed nanoparticles ranged between 20 and 50 nm revealing an inverse proportional relationship with the Dy content. Magnetic studies conducted by VSM indicated a decrease in remanent and saturation mass magnetization, respectively, in Dy-doped nanoparticles in a direct proportionality with the Dy content; the decrease was further amplified by cyclodextrin complexation. Biological assessment in the presence/absence of red light revealed a significant cytotoxic activity in melanoma (A375) and breast (MCF-7) cancer cells, while healthy keratinocytes (HaCaT) remained generally unaffected, thus revealing adequate selectivity. The investigation of the underlying cytotoxic molecular mechanism revealed an apoptotic process as indicated by nuclear fragmentation and shrinkage, as well as by Western blot analysis of caspase 9, p53 and cyclin D1 proteins. The anticancer activity for all doped Co ferrites varied was in a direct correlation to their Dy content but without being affected by the red light irradiation.

Efficacy of lidocaine wet compress combined with red-light irradiation for chronic wounds

BACKGROUND

Chronic wounds that fail to progress through normal phases of healing present a significant healthcare burden owing to prolonged treatment and associated costs. Traditional wound care typically involves regular dressing changes, which can be painful. Recent approaches have explored the use of lidocaine to manage pain and red-light irradiation (RLI), known for its anti-inflammatory and cell proliferation effects, to potentially enhance wound healing.

AIM

To investigate the therapeutic efficacy of lidocaine wet compression (LWC) combined with RLI for chronic wounds.

METHODS

We enrolled 150 patients with chronic wounds from the Wound and Ostomy Outpatient Clinic of the Second Hospital of Anhui Medical University from April to September 2022. The wounds were treated with dressing changes. The patients were randomly assigned to the control and experimental groups using a random number table and given the same first dressing change (2% LWC for 5 min and routine dressing change). From the second dressing change, in addition to 2% LWC for 5 min and routine dressing change, the experimental group received RLI, whereas the control group continued to receive the same LWC and dressing change. The first and second dressing changes were performed on days 1 and 2, respectively. The third dressing change was performed 3 d after the second change. The frequency of subsequent dressing changes was determined based on wound exudation and pain. Pain during the first three dressing changes was evaluated in both groups. The average number of dressing changes within 28 d and the degree of wound healing on day 28 were also recorded.

RESULTS

During the initial dressing change, no noticeable differences were observed in the pain levels experienced by the two groups, indicating similar pain tolerance. However, during the second and third dressing changes, the experimental group reported significantly less pain than the control group. Furthermore, over 28 d, the experimental group required fewer dressing changes than the control group.

CONCLUSION

Notably, the effectiveness of wound healing on the 28th day was significantly higher in the experimental group than that of in the control group. The combination of LWC and RLI was effective in reducing early-stage pain, promoting wound healing, decreasing the frequency of dressing changes, and enhancing patients' overall quality of life with chronic wounds.

Efficacy of Repeated Low-Level Red-Light Therapy for Slowing the Progression of Childhood Myopia: A Systematic Review and Meta-analysis

PURPOSE

To evaluate the long-term efficacy and safety of repeated low-intensity red light (RLRL) treatment for childhood myopia.

DESIGN

Systematic review and meta-analysis METHODS: We searched PubMed, Web of Science, CNKI, and Wanfang from inception to February 8, 2023. We used the RoB 2.0 and ROBINS-I tools to assess the risk of bias and then used a random-effect model to calculate the weighted mean difference (WMD) and 95% CIs. The primary outcomes were WMD in spherical equivalent refractive error (SER), WMD in axial length (AL), and WMD in subfoveal choroid thickness (SFChT). Subgroup analyses were performed to investigate the sources of heterogeneity based on variation in follow-up and study design. The Egger and Begg tests were used to assess publication bias. Sensitivity analysis was used to verify the stability.

RESULTS

This analysis included 13 studies (8 randomized controlled trials, 3 non-randomized controlled trials, and 2 cohort studies) involving 1857 children and adolescents. Eight studies met the meta-analysis criteria, and the WMD for myopia progression between RLRL and the control group was 0.68 diopters (D) per 6 months (95% CI = 0.38 to 0.97 D; I2 = 97.7%; P < .001) for SER change; -0.35 mm per 6 months (95% CI = -0.51 to -0.19 mm; I2 = 98.0%; P < .001) for AL elongation; and 36.04 µm per 6 months (95% CI = 19.61 to 52.48 µm; I2 = 89.6%; P < .001) for SFChT change.

CONCLUSIONS

Our meta-analysis shows that RLRL therapy may be effective for delaying the progression of myopia. The evidence is low certainty, and larger and better randomized clinical trials with 2-year follow-ups are needed to improve the existing state of knowledge to inform medical guidelines more comprehensively.

Photobiomodulation: A Systematic Review of the Oncologic Safety of Low-Level Light Therapy for Aesthetic Skin Rejuvenation

Photobiomodulation (PBM) therapy is an increasingly popular modality for aesthetic skin rejuvenation. PBM induces genomic, proteomic, and metabolomic processes within target cells, but such manipulation of cell behavior has led to concerns about oncologic safety. This article presents a summary of the clinical and preclinical evidence for the oncologic safety of PBM for aesthetic skin rejuvenation. A focused systematic review was performed, in which safety data from clinical trials of PBM for skin rejuvenation was supplemented by analyses of in vitro data obtained from cells derived from human skin and human neoplastic cells and in vivo data of tumors of the skin, oral cavity, and breast. Within established parameters, red and near infrared light mainly enhances proliferation of healthy cells without a clear pattern of influence on cell viability. The same light parameters mainly reduce neoplastic cell proliferation and viability or else make no difference. Invasiveness potential (appraised by cell migration assays and/or differential gene expression) is equivocal. PBM does not induce dysplastic change in healthy cells. In vivo tumor models yield varied results with no clear pattern emerging. There are no relevant clinical trial data linking PBM with any significant adverse events, including the finding of a new or recurrent malignancy.Current clinical and preclinical evidence suggests that PBM is oncologically safe for skin rejuvenation, and there is no evidence to support the proposition that it should be avoided by patients who have previously undergone treatment for cancer.

LEVEL OF EVIDENCE: 4

Low-Level Laser Therapy Induces Melanoma Tumor Growth by Promoting Angiogenesis

The effects of low-level laser therapy (LLLT) on tumor growth are inconsistent. In this study, we investigated the effects of LLLT on melanoma tumor growth and angiogenesis. C57/BL6 mice were challenged with B16F10 melanoma cells and treated with LLLT for 5 consecutive days; untreated mice were used as controls. Tumor weight, angiogenesis, immunohistochemistry, and protein levels were compared between the treated and untreated mice. In an in vitro experiment, B16F10 cells were treated with LLLT. Proteins were extracted and subjected to Western blot analysis for analyzing signaling pathways. Compared with the findings in the untreated mice, tumor weight substantially increased in the treated mice. Both immunohistochemical and Western blot analyses revealed markedly increased levels of CD31, a biomarker of vascular differentiation, in the LLLT group. In B16F10 cells, LLLT considerably induced the phosphorylation of extracellular signal-regulated kinase (ERK), which, in turn, phosphorylated p38 mitogen-activated protein kinase (MAPK). Furthermore, LLLT induced the expression of vascular endothelial growth factor, but not hypoxia-inducible factor-1α, through the ERK/p38 MAKP signaling pathways. Our findings indicate that LLLT induces melanoma tumor growth by promoting angiogenesis. Therefore, it should be avoided in patients with melanoma.

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.