Experimental Study on Blue Light Interaction with Human Keloid-Derived Fibroblasts

Label-free and real-time assessment of 660 nm red light photobiomodulation induced molecular alterations in human adipose derived mesenchymal stem cells using micro Raman spectroscopy

Therapeutic applications involving mesenchymal stem cells (MSCs) encounter challenges of attaining therapeutically potent and scaled up number during in-vitro batch culture. Recently, photobiomodulation (PBM) has emerged as a non-pharmacological method for enhancing MSC number, potency, and secretome production. However, the absence of a versatile, non-invasive technique to accurately identify PBM-induced biochemical alterations hinders the clinical translation of the approach. Raman spectroscopy (RS) can be a potential solution to this challenge. In this study, we demonstrate the utility of micro-RS to determine red light (∼660 nm) induced molecular alterations in human adipose tissue derived MSCs (hADMSCs) exposed to three different red light (∼660 nm) fluence; ∼3, 6 and 9 J/cm2. While the immediate changes in response to ∼660 nm exposure are subtle, at 6 and 24 h, there is increase in peak intensity of reducedCytochromes c, c1 and b, phenylalanine,CN stretching, CC lipids, OPO stretchingin cells. Maximum increase in intensity of these peaks was observed at ∼6 J/cm2. Raman peak at 1585 cm-1, assigned to stretching vibration (CαCm) asymmetry of reduced Cyt c and sensitive to cellular redox status, shows notable change. Further, the intensity ratio of 1585 cm-1 and 1452 cm-1, a suggestive Raman biomarker for cell proliferation, is increased in cells exposed to ∼3 &  ∼6 J/cm2 followed by a decrease in cells exposed to ∼9 J/cm2. Furthermore, both micro-RS intensity ratio (1585 cm-1/1452 cm-1) and MTT data on cell viability are in qualitative agreement with each other and show biphasic response to ∼660 nm exposure. While these results suggest the utility of micro-RS for label free assessment of PBM induced changes in hADMSCs, detailed studies on other cell types are necessary to validate the utility of micro-RS in this field.

Periostin regulates the activity of keloid fibroblasts by activating the JAK/STAT signaling pathway

A keloid is secondary to skin trauma or has spontaneously manifested as an overgrowth and occurs when the skin heals abnormally after an injury. The main pathological manifestations are abnormal proliferation of keloid fibroblasts (KEL-FIB). This study researched periostin (POSTN) on keloid fibroblasts (KEL-FIB) and the associated mechanism, aiming to provide a reference for the targeted therapy of keloid. We got tissues from Second People's Hospital of Guangxi Zhuang Autonomous Region between June 2022 and March 2023. POSTN expression was increased in keloid skin tissue and KEL-FIB than normal skin tissue and normal fibroblasts. We collected and inoculated KEL-FIB cells, transfection of si-NC (Silencing of POSTN negative control), si-POSTN (Silencing of POSTN), pcDNA-NC (Overexpression of POSTN negative control), and POSTN (Overexpression of POSTN) (Thermo Fisher Scientific) used Lipofectamine 2000 transfection reagent. Wound closure, cell proliferation viability, migrated cell numbers, and POSTN, p-JAK2, p-STAT3 protein levels were reduced in the si-POSTN group. Wound closure, cell proliferation viability, migrated cell numbers, and POSTN, p-JAK2, p-STAT3 protein levels were elevated in the POSTN group. POSTN protein levels did not changed and wound closure, cell proliferation viability, migrated cell numbers, were reduced in the POSTN + S-Ruxolitinib group. The study results indicated that POSTN promotes cell migration and proliferation by activating the JAK/STAT pathway, promoting KEL-FIB development.

The effect of continuous long-term illumination with visible light in different spectral ranges on mammalian cells

One of the biggest challenges in tissue engineering and regenerative medicine is to ensure oxygen supply of cells in the (temporary) absence of vasculature. With the vision to exploit photosynthetic oxygen production by microalgae, co-cultivated in close vicinity to oxygen-consuming mammalian cells, we are searching for culture conditions that are compatible for both sides. Herein, we investigated the impact of long-term illumination on mammalian cells which is essential to enable photosynthesis by microalgae: four different cell types-primary human fibroblasts, dental pulp stem cells, and osteoblasts as well as the murine beta-cell line INS-1-were continuously exposed to warm white light, red or blue light over seven days. We observed that illumination with red light has no adverse effects on viability, metabolic activity and growth of the cells whereas exposure to white light has deleterious effects that can be attributed to its blue light portion. Quantification of intracellular glutathione did not reveal a clear correlation of this effect with an enhanced production of reactive oxygen species. Finally, our data indicate that the cytotoxic effect of short-wavelength light is predominantly a direct effect of cell illumination; photo-induced changes in the cell culture media play only a minor role.

Unlocking the Power of Light on the Skin: A Comprehensive Review on Photobiomodulation

Photobiomodulation (PBM) is a procedure that uses light to modulate cellular functions and biological processes. Over the past decades, PBM has gained considerable attention for its potential in various medical applications due to its non-invasive nature and minimal side effects. We conducted a narrative review including articles about photobiomodulation, LED light therapy or low-level laser therapy and their applications on dermatology published over the last 6 years, encompassing research studies, clinical trials, and technological developments. This review highlights the mechanisms of action underlying PBM, including the interaction with cellular chromophores and the activation of intracellular signaling pathways. The evidence from clinical trials and experimental studies to evaluate the efficacy of PBM in clinical practice is summarized with a special emphasis on dermatology. Furthermore, advancements in PBM technology, such as novel light sources and treatment protocols, are discussed in the context of optimizing therapeutic outcomes and improving patient care. This narrative review underscores the promising role of PBM as a non-invasive therapeutic approach with broad clinical applicability. Despite the need for further research to develop standard protocols, PBM holds great potential for addressing a wide range of medical conditions and enhancing patient outcomes in modern healthcare practice.

Differential Photosensitivity of Fibroblasts Obtained from Normal Skin and Hypertrophic Scar Tissues

It is unclear whether normal human skin tissue or abnormal scarring are photoreceptive. Therefore, this study investigated photosensitivity in normal skin tissue and hypertrophic scars. The expression of opsins, which are photoreceptor proteins, in normal dermal fibroblasts (NDFs) and hypertrophic scar fibroblasts (HSFs) was examined. After exposure to blue light (BL), changes in the expression levels of αSMA and clock-related genes, specifically PER2 and BMAL1, were examined in both fibroblast types. Opsins were expressed in both fibroblast types, with OPN3 exhibiting the highest expression levels. After peripheral circadian rhythm disruption, BL induced rhythm formation in NDFs. In contrast, although HSFs showed changes in clock-related gene expression levels, no distinct rhythm formation was observed. The expression level of αSMA was significantly higher in HSFs and decreased to the same level as that in NDFs upon BL exposure. When OPN3 knocked-down HSFs were exposed to BL, the reduction in αSMA expression was inhibited. This study showed that BL exposure directly triggers peripheral circadian synchronization in NDFs but not in HSFs. OPN3-mediated BL exposure inhibited HSFs. Although the current results did not elucidate the relationship between peripheral circadian rhythms and hypertrophic scars, they show that BL can be applied for the prevention and treatment of hypertrophic scars and keloids.

The signal pathway of melatonin mediates the monochromatic light-induced T-lymphocyte apoptosis in chicken thymus

Our previous study revealed that under monochromatic red light (RL), the melatonin nuclear receptor reduces the proliferation activity of broiler thymic lymphocytes through the P65 signaling pathway. The main objective of this study was to investigate the signal mechanism by which RL decreases thymic lymphocyte proliferation. Initially, broilers were purchased and randomly assigned to be fed under white light (WL), red light (RL), green light (GL), and blue light (BL). Pinealectomy was performed 3 d later, and the broilers were euthanized after 14 d. The results showed that the expression of the antiapoptotic proteins Bcl-2/Bcl-xl decreased under RL, while the expression of the pro-apoptotic factor Bax/caspase-3 and the pro-inflammatory factors INF-γ/TNF-α/IL-6 increased. After pinealectomy, the expression of Bax/TNF-α/IL-6 increased in conjunction with the decrease in Bcl-2 expression. In vitro experiments demonstrated that exogenous melatonin decreased the expression of Bax/TNF-α/IL-6 in thymic lymphocytes of chicks reared under RL. This melatonin-induced effect was enhanced by SR1078 (RORα/RORγ agonist) but attenuated by SR3335 (RORα antagonist) and BAY (P65 antagonist). These findings revealed that the melatonin nuclear receptor RORα/RORγ promotes the expression of the pro-apoptotic factor Bax/caspase-3 and the pro-inflammatory factors INF-γ/TNF-α/IL-6, while inhibiting the expression of the antiapoptotic factor Bcl-2/Bcl-xl. Our research suggested the signaling pathway of monochromatic red light impacts the apoptosis of thymus lymphocytes in broiler.

Effects of photobiomodulation with blue Light Emitting Diode (LED) on the healing of skin burns

The management of skin burns is still challenging. Among the therapeutic methods used, there are topical treatments with pharmacological and herbal agents, low-intensity therapeutic ultrasound, use of biomaterials, reconstructive techniques and photobiomodulation therapy. The aim of this study was to evaluate the effects of photobiomodulation with blue Light Emitting Diode (LED) on burn healing. Fifty Wistar rats were divided into control (CTRL) (n = 25) and blue LED (LED) (n = 25), with subgroups (n = 5) for each time of euthanasia (7, 14, 21, 28 and 32 days). Treated animals were daily irradiated (470 nm, 1W, 0.44 W/cm2, 50 J/cm2). Clinical evaluations were performed and the Wound Retraction Index (WRI) was determined. Histological sections were submitted to hematoxylin-eosin, toluidine blue and the immunohistochemical technique, with anti-α-SMA and anti-TGF-β1 antibodies. All data were directly collected by previously calibrated evaluators in a blind manner. The values were included in a statistical program. For all statistical tests used, 5% significance level (p < 0.05) was considered. No statistically significant differences in WRI between groups were observed (p > 0.05). Re-epithelialization was higher using LED at 7 and 14 days (p < 0.05) and greater amount of inflammatory cells was observed at 7 days (p = 0.01). With LED at 21 and 32 days, greater number of mast cells were observed (p < 0.05), as well as smaller number of myofibroblasts at 14, 21, 28 and 32 days (p < 0.05) and lower percentage of TGF-β1 positive cells in the conjunctiva at 7, 14 and 21 days (p < 0.05). Negative correlations were observed in LED between the percentage of TGF-β1 in the epithelium and the mean number of inflammatory cells and number of myofibroblasts (p < 0.05). The results suggest that, depending on the period, blue LED can modulate the healing processes of third-degree skin burns, such as re-epithelialization, inflammatory response, mast cell concentration, myofibroblast differentiation and TGF-β1 immunoexpression. Despite these effects, this therapy does not seem to have significant influence on the retraction of these wounds. Future studies, using different protocols, should be carried out to expand the knowledge about the photobiomodulatory mechanisms of this type of light in the healing process.

Ear keloids: An innovative 3-steps combined treatment

INTRODUCTION

An excessive proliferation of fibroblasts and collagen synthesis after an injury may lead to a benign fibrous tumor, known as keloid, which does not regress spontaneously. Earlobes are a very frequent site of onset, since after a trauma (i.e., piercing) keloids may develop either on the helix and on the anterior or posterior lobe, from a few months up to several years after the injury.

OBJECTIVES

To report the effectiveness of a combined protocol of CO2 laser + Dye laser + a portable Blue LED Light medical device for Photobiomodulation Therapy (EmoLED®).

METHODS

Fifty-two patients with a total of 56 ear keloids have been treated in the same session with a single CO2 laser procedure + a pulsed Dye laser procedure with an adjunctive EmoLED® procedure for 3 up to 6 min. A monthly follow-up has been performed with an adjunctive EmoLED® session in case of signs of inflammation.

RESULTS

Among 56 treated keloids, 89.3% of them (50/56) did not recur during a follow-up period (from 6 up to 24 months, mean 16.3 months) while six keloids recurred (6/56, 10.7%) with mild thickening of the scar, thus requiring further treatments.

CONCLUSIONS

Even if an excellent outcome obtained by the synergistic effect of combined laser treatments has already been described (i.e., CO2 laser + Dye Laser), the present study showed the adjuvant procedure with EmoLED® can reduce significantly the risk of keloids recurrences.

Cellular and Molecular Processes in Wound Healing

This review summarizes the recent knowledge of the cellular and molecular processes that occur during wound healing. However, these biological mechanisms have yet to be defined in detail; this is demonstrated by the fact that alterations of events to pathological states, such as keloids, consisting of the excessive formation of scars, have consequences yet to be defined in detail. Attention is also dedicated to new therapies proposed for these kinds of pathologies. Awareness of these scientific problems is important for experts of various disciplines who are confronted with these kinds of presentations daily.

Blue-LED-Light Photobiomodulation of Inflammatory Responses and New Tissue Formation in Mouse-Skin Wounds

Background: Recent studies evidence that blue-LED-light irradiation can modulate cell responses in the wound healing process within 24 h from treatment. This study aims to investigate blue-light (410-430 nm) photobiomodulation used in a murine wound model within six days post-treatment. Methods: A superficial wound was made in 30 CD1 male mice. The injuries were treated with a blue LED light (20.6 J/cm²), and biopsies were collected at 24, 72, and 144 h. Histology, fluorescence analysis, and advanced microscopy techniques were used. Results: We can observe an increase in the cellular infiltrate response, and in mast-cell density and their degranulation index correlated to the expression of the major histocompatibility complex after 24 h. Furthermore, after six days, the vessel density increases with the expression of the platelet-derived growth factor in the mast cells. Finally, collagen deposition and morphology in the treated wounds appear more similar to unwounded skin. Conclusions: Blue-light photobiomodulation stimulates several cellular processes that are finely coordinated by mast cells, leading to more rapid wound healing and a better-recovered skin morphology.

Liquid crystalline lipid nanoparticle promotes the photodynamic activity of gallium protoporphyrin against S. aureus biofilms

Antimicrobial photodynamic therapy (aPDT) has emerged as an innovative strategy to combat antibiotic resistant microbes; yet aPDT efficacies against biofilms are sub-optimal due to inability of photosenstizers to reach microbes embedded in biofilm matrix. To overcome this challenge, liquid crystal lipid nanoparticles (LCNP) were employed in this study as a smart, biocompatible and triggerable delivery system for the new photosensitizer gallium protoporphyrin (GaPP), due to their capabilities in promoting efficient antimicrobial delivery to biofilms. The relationship between GaPP loading of LCNP, reactive oxygen species (ROS) production and the in vitro antibacterial activity against two antibiotic resistant Staphylococcus aureus strains was established. LCNP substantially improved the antibacterial activity of GaPP, completely eradicating S. aureus and MRSA planktonic cultures, using a GaPP concentration of 0.8 μM and light dose 1.9 J/cm². At the same concentration and light dose, unformulated GaPP triggered only a 4 log₁₀ and 2 log₁₀ reduction in respective planktonic cultures. Most importantly, the activity of GaPP against biofilms was enhanced by 2-fold compared to unformulated GaPP, reducing the viability of S. aureus and MRSA biofilms by 8 log₁₀ and 5 log₁₀, respectively. The biosafety of photoactivated GaPP-LCNP was evaluated against human fibroblasts, which indicated a high safety profile of the treatment. Therefore, these findings encourage further investigations of GaPP-LCNP as a potential treatment for localized chronic infections.

Photobiomodulation Therapy: A New Light in the Treatment of Systemic Sclerosis Skin Ulcers

INTRODUCTION

Skin ulcers (SU) represent one of the most frequent manifestations of systemic sclerosis (SSc), occurring in almost 50% of scleroderma patients. SSc-SU are often particularly difficult to treat with conventional systemic and local therapies. In this study, a preliminary evaluation of the role and effectiveness of blue light photobiomodulation (PBM) therapy with EmoLED^® in the treatment of scleroderma skin ulcers (SSc-SU) was performed.

METHODS

We retrospectively analyzed 12 consecutive SSc patients with a total of 15 SU on finger hands. All patients were treated with adequate systemic therapy and local treatment for SU; after a standard skin ulcer bed preparation with debridement of all lesions, EmoLED^® was performed. All patients were locally treated every week during 2 months of follow-up; SU data were collected after 4 weeks (T4) and 8 weeks (T8). Eight SSc patients with comparable SU were also evaluated as controls.

RESULTS

The application of EmoLED^® in addition to debridement apparently produced faster healing of SU. Complete healing of SU was recorded in 41.6% cases during EmoLED^® treatment. Significant improvements in SU area, length, and width, wound bed, and related pain were observed in EmoLED^® patients from T0 to T8. Control subjects treated with standard systemic/local therapies merely showed an amelioration of SU area and width at the end of the follow-up. No procedural or post-procedural adverse events were reported.

CONCLUSIONS

The positive clinical results and the absence of side effects suggest that EmoLED^® could be a promising tool in the management of SSc-SU, with an interesting role to play in the healing process in addition to conventional systemic and local treatments.

Photobiomodulation of oral fibroblasts stimulated with periodontal pathogens

Photobiomodulation (PBM) utilises light energy to treat oral disease, periodontitis. However, there remains inconsistency in the reporting of treatment parameters and a lack of knowledge as to how PBM elicits its molecular effects in vitro. Therefore, this study aimed to establish the potential immunomodulatory effects of blue and near infra-red light irradiation on gingival fibroblasts (GFs), a key cell involved in the pathogenesis of periodontitis. GFs were seeded in 96-well plates in media + / - Escherichia coli lipopolysaccharide (LPS 1 μg/ml), or heat-killed Fusobacterium nucleatum (F. nucleatum, 100:1MOI) or Porphyromonas gingivalis (P. gingivalis, 500:1MOI). Cultures were incubated overnight and subsequently irradiated using a bespoke radiometrically calibrated LED array (400-830 nm, irradiance: 24 mW/cm² dose: 5.76 J/cm²). Effects of PBM on mitochondrial activity (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and adenosine triphosphate (ATP) assays, total reactive oxygen species production (ROS assay) and pro-inflammatory/cytokine response (interleukin-8 (IL-8) and tumour growth factor-β1 (TGFβ1)) were assessed 24 h post-irradiation. Data were analysed using one-way ANOVA followed by the Tukey test. Irradiation of untreated (no inflammatory stimulus) cultures at 400 nm induced 15%, 27% and 13% increases in MTT, ROS and IL-8 levels, respectively (p < 0.05). Exposure with 450 nm light following application of P. gingivalis, F. nucleatum or LPS induced significant decreases in TGFβ1 secretion relative to their bacterially stimulated controls (p < 0.001). Following stimulation with P. gingivalis, 400 nm irradiation induced 14% increases in MTT, respectively, relative to bacteria-stimulated controls (p < 0.05). These findings could identify important irradiation parameters to enable management of the hyper-inflammatory response characteristic of periodontitis.

The Aqueous Extract of Polypodium leucotomos (Fernblock®) Regulates Opsin 3 and Prevents Photooxidation of Melanin Precursors on Skin Cells Exposed to Blue Light Emitted from Digital Devices

The effects of sun exposure on the skin and specifically those related to pigmentation disorders are well known. It has recently been shown that blue light leads to the induction of oxidative stress and long-lasting pigmentation. The protective effect of an aqueous extract of Polypodium leucotomos (Fernblock^®) is known. Our aim was to investigate the action mechanism of Fernblock^® against pigmentation induced by blue light from digital devices. Human fibroblasts (HDF) and murine melanocytes (B16-F10) were exposed to artificial blue light (a 400–500 nm LED lamp). Cell viability, mitochondrial morphology, and the expression of the mitogen-activated protein kinase (MAPK) p38, known markers involved in the melanogenesis pathway, were evaluated. The activation of Opsin-3, a membrane protein sensitive to blue light that triggers the activation of the enzyme tyrosinase responsible for melanogenesis in melanocytes, was also analyzed. Our results demonstrated that pretreatment with Fernblock^® prevents cell death, alteration of mitochondrial morphology, and phosphorylation of p38 in HDF exposed to blue light. In addition, Fernblock^® significantly reduced the activation of Opsin-3 in melanocytes and the photo-oxidation of melanin, preventing its photodegradation. In sum, Fernblock^® exerts beneficial effects against the detrimental impact of blue light from digital devices and could prevent early photoaging, while maintaining skin homeostasis.

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.