IPL irradiation rejuvenates skin collagen via the bidirectional regulation of MMP-1 and TGF-β1 mediated by MAPKs in fibroblasts

Intense pulsed light treatment for the management of meibomian gland dysfunction

PURPOSE OF REVIEW

Meibomian gland dysfunction (MGD) is one of the most common disorders encountered by ophthalmologists, and its management can prove challenging for both clinicians and patients. Intense pulsed light (IPL), which has been historically used in the field of dermatology, has emerged as a tool to help improve meibomian gland function. The goal of this review is to assess the clinical efficacy, utility, and safety of IPL for the treatment of MGD.

RECENT FINDINGS

In recent randomized controlled trials, IPL has been shown to improve meibomian gland function, and subsequently tear film quality and dry eye symptoms. The mechanism of action still remains unclear. Recent literature suggests that IPL may also be used in conjunction with other therapies, such as meibomian gland expression, low-level light therapy, and thermal pulsation. Careful attention should be placed on each patient's Fitzpatrick skin type, as well as protecting the ocular structures to reduce the risk of adverse effects. Cost, accessibility, as well as a limited duration of efficacy may be drawbacks.

SUMMARY

There is significant evidence supporting that IPL may be used as a potential well tolerated and effective treatment for MGD, though there are certain caveats regarding its long-term efficacy, accessibility, and cost.

Using an intense pulsed light (IPL) module for the treatment of pigmented lesions

BACKGROUND

Pigmented lesions are largely benign and may lead to extreme distress. Various light and lasers may be used to treat pigmentation, often Q-switched lasers are considered the method of choice, while intense pulsed light (IPL) devices may offer a less invasive treatment with a shorter downtime.

OBJECTIVE

The purpose of this study is to evaluate the safety and efficacy of a narrowband IPL module for the treatment of pigmented lesions.

METHODS

A retrospective study of 20 patients with pigmented lesions underwent treatment with an IPL module. Treatment was assessed by blinded evaluation of clinical photographs using a GAIS scale of 0-10, as well as through patient satisfaction ratings on a scale of 0-10. Throughout the treatment, pain levels and adverse events were monitored.

RESULTS

The mean GAIS score was 7.55 ± 1.15 (mean ± SD), and the mean patient satisfaction score was 7.3 ± 1.26 (mean ± SD). There was a strong positive correlation between GAIS and patient satisfaction scores (r = 0.83), and no significant difference between them (p-value = 0.516). The number of treatments did not significantly affect GAIS and patient satisfaction scores (p-values 0.364 and 0.126). Additional positive unexpected outcomes were improved skin firmness and reduced wrinkles.

CONCLUSION

The results of the study indicate that the IPL module is both safe and effective in treating pigmented lesions and may have the potential to stimulate collagen production.

Quality of life improvement in dry eye patients after intense pulsed light therapy compared to punctal plugs

PURPOSE

The purpose of the study was to evaluate the quality of life (QOL) improvement in evaporative dry eye patients after treatment with intense pulsed light (IPL) therapy compared to punctal plug insertion.

METHODS

A prospective comparative interventional study included 30 patients with moderate-to-severe evaporative dry eye. Patients' QOL affection before and after treatment was assessed by the Ocular Surface Disease Index (OSDI) questionnaire. Fifteen patients were treated with IPL therapy (Group 1). The other 15 patients were treated with silicone punctal plug insertion (Group 2).

RESULTS

Improvement of patients' QOL was noticed in all patients of Group 1, with significant improvement of OSDI score from a mean value of 56.9 to 22.9 (P = 0.001). Improvement was noticed in 80% of Group 2 patients (mean OSDI score pretreatment: 53.8 and posttreatment: 31.7, P = 0.017). The tear breakup time (TBUT) in Group 1 significantly improved from a mean of 3.2 s to 5.9 s (P = 0.001), whereas it showed no significant changes in Group 2 (mean TBUT pretreatment: 3.6 s and posttreatment: 3.9 s, P = 0.654). Complications occurred in 13.3% in Group 2, including punctal granuloma and proximal canalicular obstruction. No adverse effects were recorded in Group 1.

CONCLUSION

IPL therapy had better results with more improvement of patients' QOL compared to punctal plugs. It also showed a better safety profile with no reported complications.

Multi-Frequency RF Combined with Intense Pulsed Light Improves Signs and Symptoms of Dry Eye Disease Due to Meibomian Gland Dysfunction

Purpose

To evaluate the efficacy of multi-frequency RF and IPL + MGX combination for treatment of Meibomian Gland Dysfunction (MGD).

Patients and Methods

Eligible subjects had signs and moderate-to-severe symptoms of DED (Dry Eye Disease) due to MGD. Subjects underwent 4 treatments at 2-week intervals. Each treatment consisted of intense pulsed light (IPL) followed by radiofrequency (RF) on the periocular skin, followed by meibomian gland expression (MGX). The main outcome measure was the quality of meibum in 15 meibomian glands along the lower eyelid, using the modified Meibomian Gland Score (mMGS). The main hypothesis was a reduction of mMGS between the baseline (BL) and the follow-up (FU). Other outcome measures, such as symptoms measured with the OSDI (Ocular Surface Disease Index) questionnaire, meibography, non-invasive tear break-up time (NIBUT), and matrix metallopeptidase 9 (MMP-9) levels in tear samples were evaluated as well.

Results

31 subjects completed the FU. Between BL and FU, mMGS decreased from 30.4 (8.5) to 9.3 (9.5) (-69.3%, 95% CI: -55.6% to -82.9%, p<0.0001); OSDI decreased from 63.6 (17.2) to 25.0 (20.6) (-60.7%, 95% CI: -47.8% to -73.5%, p<0.0001); NIBUT did not change (p=0.92). An adjusted model with a historical control was constructed to allow the comparison of these subjects with those treated similarly with IPL+MGX (but without RF) in a different study. This analysis identified that the change in mMGS was larger when RF was included (-20.9 vs -18.3, adjusted p-value (p_adjusted) <0.05). The difference in OSDI change was not significant (-38.1 vs -25.5, p_adjusted = 0.196).

Conclusion

Combination of multi-frequency RF and IPL+MGX improves signs and symptoms of MGD. In comparison to a historical control, improvements were generally larger. A randomized controlled study comparing the combination of RF and IPL+MGX with IPL+MGX alone is required to further elaborate the relative contribution of RF.

Clinical and Molecular Outcomes After Combined Intense Pulsed Light Therapy With Low-Level Light Therapy in Recalcitrant Evaporative Dry Eye Disease With Meibomian Gland Dysfunction

PURPOSE

Dry eye disease (DED) is a leading cause of ocular morbidity worldwide. This study evaluates the effects of combined light therapy [intense pulsed light (IPL) and low-level light therapy (LLLT)] on clinical and molecular outcomes in evaporative DED with meibomian gland dysfunction (MGD).

METHODS

This prospective study evaluated 94 eyes (47 subjects) with chronic MGD treated with combined light therapy. Patients underwent a detailed evaluation of MGD and DED using the Ocular Surface Disease Index, dry eye tests-tear breakup time and Schirmer test, ocular surface staining, meibomian gland expressibility scoring, and meibography. Patients underwent a single session of combined light therapy (IPL + LLLT treatment) using the Eye-light device. All these tests were repeated at 3 and 6 months after treatment. Tear fluid and ocular surface wash samples were collected from a subset of patients before and after treatment for cellular and secreted immune factor profiling by flow cytometry.

RESULTS

Combined light therapy (IPL + LLLT) demonstrated a marked improvement in the clinical metrics studied. Three months after treatment, Ocular Surface Disease Index showed a significant reduction in 95.6% ( P < 0.0001), tear breakup time increased in 72.3% ( P < 0.0001), and meibomian gland expressibility scoring increased in 80.8% ( P < 0.0001) of the eyes. These effects were observed to be sustained during the 6-month follow-up visit. Significant ( P < 0.05) reduction in tear fluid levels of interleukin-1β, interleukin-17F, and MMP9; MMP9/TIMP1 ratio; and ocular surface B-cell proportions was observed.

CONCLUSIONS

Combined light therapy shows promising results in patients with chronic MGD and DED, even in recalcitrant cases. Clinical and molecular factor alterations support the improved symptomatology and reduced inflammation.

Application and mechanism of probiotics in skin care: A review

BACKGROUND

Skin problems have been the focus of attention in recent years. Skin aging, wrinkles, pigmentation, dryness has been a problem that makes people feel troubled. Researchers have been devoted to find ways to solve these skin problems. Micro-ecological skin care is a popular concept these days, and improving skin health through the use of probiotics is a hot topic of discussion.

OBJECTIVE

Many experimental studies have shown that probiotics have a good effect on improving skin problems. This paper aims to comprehensively review the application and mechanism of probiotics in skin care and provide theoretical basis for the application of probiotics in skin care.

METHODS

Literatures in this review were searched in PubMed, China National Knowledge Infrastructure (CNKI), Web of Science, and Science Direct.

RESULTS

Probiotics have potent effects on skin whitening, moisturizing, anti-aging, anti-wrinkle and removing body odor.

CONCLUSIONS

The effects of probiotics on skin whitening, skin moisturizing, anti-aging, improving skin wrinkles and removing body odor were reviewed, which provided a new basis for the extensive application of probiotics in skin care.

The Effect of Intense Pulsed Light on the Skin Microbiota and Epidermal Barrier in Patients with Mild to Moderate Acne Vulgaris

BACKGROUND AND OBJECTIVES

The skin microbiota partly determined by epidermal barrier plays an important role in acne vulgaris and intense pulsed light (IPL) has been verified as a safe and effective therapeutic option for this disease. Nevertheless, the exact role of the IPL treatment on the skin microbiota and epidermal barrier for patients with acne vulgaris remains unclear. This article was designed to solve this problem.

STUDY DESIGN/MATERIALS AND METHODS

Nineteen healthy controls and 20 patients with mild to moderate acne were enrolled in this study, who received IPL treatment for 12 weeks. The epidermal barrier and skin samples were collected at baseline and after treatment. The microbial diversity was analyzed based on a high-throughput sequencing approach, which targets the V3-V4 region of the bacteria 16S ribosomal RNA genes.

RESULTS

After treatment of IPL, the Global Acne Grading System (GAGS) scores, sebum, sclererythrin, and red area of patients were significantly improved by IPL treatment (P < 0.05). Although there was no difference in microbiota diversity before and after IPL treatment, the Nonmetric Multidimension Scaling (NMDS) analysis showed that the samples of the acne patients before and after treatment could be divided into two different sets by skin microbiota (P = 0.011), which could be verified by heatmap analysis. Moreover, we found that the relative abundance of Staphylococcus epidermidis (S. epidermidis) significantly increased, but Cutibacterium acnes (C. acnes) decreased after IPL treatment. The sebum concentration was positively correlated with PH value (R = 0.525, P = 0.017), and the GAGS was positively associated with both sclererythrin (R = 0.477, P = 0.002) and red area (R = -0.503, P = 0.001).

CONCLUSIONS

IPL could successfully improve the GAGS scores of acne vulgaris, as well as regulate the equilibrium between C. acnes and S. epidermidis, and inhibit the sebum secretion. Lasers Surg. Med. © 2021 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.

Astragaloside IV Promotes Antiphotoaging by Enhancing the Proliferation and Paracrine Activity of Adipose-Derived Stem Cells

Photoaging is a degenerative biological process. As a kind of pluripotent stem cells, adipose-derived stem cells (ADSCs) are widely used in the treatment of photoaging. Therefore, we aimed to find an effective way to improve the antiaging ability of ADSCs. In this study, we isolated ADSCs and assessed multilineage differentiation ability and markers. Cultured ADSCs were preconditioned with astragaloside IV (ASI) at 10^-7, 10^-6, and 10^-5 M. Cell proliferation was assessed by CCK-8 assay and cytokine secretion by enzyme-linked immunosorbent assay (ELISA). A fibroblast photoaging model was established and cocultured with normal ADSCs or ASI-treated ADSCs. Matrix metalloproteinase-1 (MMP1) and type I procollagen (PC-I) secreted by human dermal fibroblasts were measured by ELISA. The effects of ASI-treated ADSCs on skin texture, including dermal thickness, collagen content, and microvessel density, in a photoaging animal model were analyzed using H&E staining, Masson staining, and CD31 immunohistochemistry, respectively. We found that 10^-6 M ASI could significantly promote cell proliferation and stimulate robust secretion of growth factors in ADSCs. Furthermore, our data showed that ASI-treated ADSCs could markedly reverse the ultraviolet B-induced decrease of PC-I secretion and increase of MMP-1 release in fibroblasts. Moreover, in photoaged skin of nude mice, ASI-treated ADSCs significantly increased dermal thickness, collagen content, and microvessel density.

The Efficacy of IPL in Periorbital Skin Rejuvenation: An Open-Label Study

Introduction: Intense pulsed light (IPL) is one of the effective methods used to treat the signs of facial aging. However, its efficacy in improving the appearance of periorbital wrinkles has always been evaluated in the context of whole-face rejuvenation and not studied in its own right. Therefore, in this study, we sought to examine the effectiveness and side effects of IPL in periorbital skin rejuvenation. Methods: In this uncontrolled, open-label clinical trial, 38 patients referred to the Behrooz professional skin clinic for signs of periorbital skin aging were recruited. The patients underwent three treatment sessions with IPL at one-month intervals and were evaluated for treatment side effects after each session. Six months after the final IPL session, patients were examined to assess the level of symptom improvement. The patients were photographed at each treatment session and on the 6-month follow-up visit. Before and after treatment, the patient images were evaluated by two dermatologists unaffiliated with the study to determine the extent of improvement in the appearance of wrinkles and skin texture. Results: Six months' post-treatment, excellent improvement was observed in 3 patients (9.1%), considerable improvement in 7 patients (21.2%), moderate improvement in 9 patients (27.3%), mild improvement in 9 patients (27.3%), and finally little or no improvement in 5 patients (15.1%). A comparison of improvement scores based on the Fitzpatrick skin phenotype did not show significant differences (P=0.674). Four patients (12.1%) were dissatisfied with the treatment, whilst 17 patients (51.5%) reported moderate to considerable satisfaction with IPL rejuvenation. Conclusion: During facial rejuvenation, IPL can be used to improve periorbital skin aging.

Effect of Intense Pulsed Light Therapy on Tear Proteins and Lipids in Meibomian Gland Dysfunction

PURPOSE

To assess the effect of a novel intense pulsed light (IPL) therapy on tear proteins and lipids in eyes with Meibomian gland dysfunction (MGD).

METHODS

Twenty-four eyes of 12 patients with MGD were recruited and received five overlapping flashes (565-1400 nm) directed at the lower eyelid. The IPL parameters include intensity: 2.5 to 6.5 J/cm2, voltage: 100 to 240 V, frequency: 50 to 60 Hz, input: 16 W, maximum optical energy: 23 J, pulse duration: <2.0 ms, and repetition time: 1-3.5 s. Tear samples were evaluated immediately before and 2 weeks after IPL therapy and included measurements of protein concentration, electrophoretic mobility by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, lipid profile assessments, and thin-layer chromatography (TLC) for phospholipids.

RESULTS

Significant improvements were observed in tear protein concentrations and molecular weight after IPL therapy. The most pronounced effect was in the molecular weight of tear lysozyme, lactoferrin, and albumin. Tear lipids showed an improvement in the concentrations of total lipids, triglycerides, cholesterol, and phospholipids. On TLC, the tears in patients with MGD had significantly lower amounts of anionic phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine but amounts zwitterionic neutral phospholipid phosphatidylcholine were normal. These anionic phospholipids showed obvious recovery after IPL therapy.

CONCLUSION

IPL therapy is effective in eyes with MGD. It improved tear protein and lipid content and composition. The anionic phospholipids were more responsive to IPL therapy than were the other zwitterionic phospholipids.

Intense Pulsed Light Therapy In The Treatment Of Meibomian Gland Dysfunction: Current Perspectives

Dry eye disease (DED) is among the most common condition encountered during ophthalmic practice, reducing patient's quality of life and work productivity. Most of DED cases have an evaporative component originated from a meibomian gland dysfunction (MGD). Conventional treatments such as tear substitute, warm compresses, topical anti-inflammatory agents and/or antibiotics often are not able to provide a complete and long-term relief of symptoms and signs. Intense pulsed light (IPL) has been widely used in the field of dermatology to treat various skin conditions, and it has been recently introduced in the ophthalmic practice for the management of DED due to MGD. To date, several clinical studies showed positive results of IPL as adjuvant therapy for DED in terms of both safety and efficacy. The treatment is usually well accepted among patients for its non-invasive nature; very rare are the major adverse reactions. Moreover, results can be maintained over time with periodic sessions of IPL. This review summarizes the clinical outcomes of IPL therapy in MGD patients pointing out its potential role in the therapeutic algorithm of the disease. Further clinical investigations are desirable to identify factors able to predict the positive outcomes of the procedure and therefore to select in advance those patients who best benefit from IPL therapy.

Q-switched 1064-nm dymium-doped yttrium aluminum garnet laser irradiation induces skin collagen synthesis by stimulating MAPKs pathway

The 1064-nm Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser is widely used in clinical practice. However, the effects of 1064-nm Q-switched Nd:YAG laser on skin collagen generation have not been fully elucidated. The objectives of the present study were to investigate whether the 1064-nm Q-switched Nd:YAG laser can be used for non-ablative rejuvenation and to explore the possible mechanism underlying the effects. Six-week-old SKH-1 hairless mice were irradiated by the 1064-nm Nd:YAG laser at fluences of 0, 0.5, 1, 1.5, and 2 J/cm², respectively. The contents of hydroxyproline and hydration were detected after laser irradiation. Moreover, hematoxylin-eosin (HE) staining was preformed to evaluate the dermal thickness. Immunofluorescence was used to detect the expressions of MMP-2 and TIMP-1 in the skin after laser irradiation. Furthermore, qRT-PCR was performed to determine the expressions of TGF-β1 and Smad3. In addition, the expressions of ERK1/2, p-ERK1/2, p38, p-p38, JNK, ERK5, and collagen were evaluated by Western blotting. The results indicated that the levels of hydroxyproline, hydration, and collagen were markedly increased; both the thickness of dermal was enhanced after low dose of laser treatment. Moreover, the expression of TIMP-1 was significantly increased, whereas the expression of MMP-2 was remarkably decreased after laser irradiation. Meanwhile, TGF-β1, Smad3, p-ERK1/2, p-P38, and JNK productions were significantly enhanced in irradiated group compared with the ones non-irradiated. Nevertheless, no significant changes were observed in the expression of ERK5 after irradiation. In summary, our study demonstrated that Q-switched 1064-nm Nd:YAG laser can induce collagen generation, at least in part, through activating TGF-β1/Smad3/MAPK signaling pathway.

Intense pulsed light for evaporative dry eye disease

There is a clear association between dry eye disease (DED) and skin inflammatory diseases occurring in close proximity to the eyelids, such as facial skin rosacea. Intense pulsed light (IPL) is widely accepted as a treatment for skin rosacea. A number of recent studies demonstrated that, in patients suffering from meibomian gland dysfunction (MGD), IPL therapy also reduces signs and symptoms of DED. Despite these encouraging results, in the context of DED and MGD, the mechanisms of action of IPL are not well understood. The purpose of this review was to raise the potential mechanisms of action and to discuss their plausibility.

Ganoderma lucidum polysaccharides protect fibroblasts against UVB-induced photoaging

Ganoderma lucidum has featured in traditional Chinese medicine for >1,000 years. Ganoderma polysaccharides (GL-PS), a major active ingredient in Ganoderma, confer immune regulation, antitumor effects and significant antioxidant effects. The aim of the present study was to investigate the efficacy and mechanism of GL‑PS‑associated inhibition of ultraviolet B (UVB)‑induced photoaging in human fibroblasts in vitro. Primary human skin fibroblasts were cultured, and a fibroblast photoaging model was built through exposure to UVB. Cell viability was measured by MTT assay. Aged cells were stained using a senescence‑associated β-galactosidase staining (SA‑β‑gal) kit. ELISA kits were used to analyze matrix metalloproteinase (MMP) ‑1 and C‑telopeptides of Type I collagen (CICP) protein levels in cellular supernatant. ROS levels were quantified by flow cytometry. Cells exposed to UVB had decreased cell viability, increased aged cells, decreased CICP protein expression, increased MMP‑1 protein expression, and increased cellular ROS levels compared with non‑exposed cells. However, cells exposed to UVB and treated with 10, 20 and 40 µg/ml GL‑PS demonstrated increased cell viability, decreased aged cells, increased CICP protein expression, decreased MMP‑1 protein expression, and decreased cellular ROS levels compared with UVB exposed/GL‑PS untreated cells. These results demonstrate that GL‑PS protects fibroblasts against photoaging by eliminating UVB‑induced ROS. This finding indicates GL‑PS treatment may serve as a novel strategy for antiphotoaging.

Effect of intense pulsed light on the expression of aquaporin 3 in rat skin

Intense pulsed light (IPL) technology has been popularly employed in clinical treatments for dermatological and cosmetic purposes in recent years; yet, the underlying mechanisms of its functions are not fully elucidated. On the other hand, aquaporin (AQP) 3, a member of a subgroup of the aquaporin family that transports both water and small solutes, such as glycerol, has been documented to play an important role in the skin homeostasis. We thus examined the possible involvement of AQP3 in the functional mechanisms of IPL irradiation. Rat dorsal skin areas were irradiated one to three times with IPL at doses of 15, 25, and 35 J/cm2. Skin specimens were collected 7 days after the final irradiation and analyzed for changes in histology, skin hydration, mRNA, and protein expressions of AQP3. IPL induced no significant variations in the mRNA expression levels. Twice or thrice irradiation at the dose of 25 or 35 J/cm2 significantly enhanced AQP3 protein expression. Immunofluorescence study revealed that AQP3 was mainly localized to keratinocyte membranes in the basal layer of epidermis, and the localization was unaltered by IPL. In addition, the pattern of IPL-induced changes in skin hydration was generally coincided with the expression profile of AQP3. These results suggest the possibility that one of the functional mechanisms of IPL might be related to the regulation of AQP3 protein expression.

Increased fibroblast proliferation and activity after applying intense pulsed light 800-1200 nm

BACKGROUND AND OBJECTIVES

Light devices emitting near infrared have been shown to be highly effective for the skin rejuvenation but biochemical and molecular mechanism or optimum dose treatment are not well-known. In our study we try to elucidate why systems emitting near infrared produce skin improvement such as fibroblasts proliferation, increase in gene expression or extracellular matrix (ECM) protein production.

STUDY DESIGN/MATERIALS AND METHODS

1BR3G human skin fibroblasts were used to test the effects of an intense pulsed light device emitting with an 800-1200 nm filter (MiniSilk FT manufactured by Deka(®)). In our protocol, fibroblasts were irradiated twice successively with a 10 Hz frequency, with a total fluence up to 60 J/cm(2) for 15s each pass. After incubating for 48 h, fibroblasts were harvested from the culture plates to test cell proliferation by flow cytometer. To determine changes in gene expression (mRNA levels for collagen types I and III and metalloproteinase 1 (MMP-1)) and protein production (hyaluronic acid, versican and decorin) tests were performed after irradiation.

RESULTS

After 48 h irradiation, 1BR3G human skin fibroblasts were observed to proliferate at a fast rate. The study of ECM macromolecules production using ELISA showed an increase of hyaluronic acid and versican production but no changes were observed for decorin. With RT-PCR assays, an increase in mRNA for collagen type I, type III and MMP-1 were observed.

CONCLUSION

Intense pulsed light emitting near infrared applied in vitro cultured cells increases fibroblasts proliferation and activity, which can be a possible mechanism of action for these devices in aging skin treatment.

Investigation of the 1064 nm Q-switched Nd:YAG laser on collagen expression in an animal model

BACKGROUND AND PURPOSE

The objective of this study was to evaluate the changes of collagen expression and its possible molecular mechanism in the rat skin induced by 1064 nm Q-switched Nd:YAG laser treatments.

METHODS

The dorsal skin of Sprague-Dawley (SD) rats was irradiated with the 1064 nm laser at fluences of 0, 0.6, 1.5, and 2.5 J/cm2, respectively. Then biochemical analysis was used to quantify hydroxyproline content in the skin. The mRNA expressions of procollagen, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs) were analyzed by using reverse transcription-polymerase chain reaction (RT-PCR). The activities of mitogen-activated protein kinase (MAPK) family members were detected by Western blot analysis.

RESULTS

The 1064 nm laser treatments led to a marked increase in collagen content in a dose-dependent manner. The expression of types I and III collagen, TIMP1 and TIMP2, in the skin was markedly upregulated, whereas the expression of MMP2 and MMP3 was significantly decreased after laser treatments. Both extracellular signal-related kinase (Erk)1/2 and JNK MAPK pathways were activated by the 1064 nm laser irradiation.

CONCLUSIONS

The 1064 nm laser irradiation could markedly increase collagen synthesis and inhibit collagen degradation. The activation of Erk1/2 and JNK MAPK seems to play a role in collagen production in the rat skin, induced by the 1064 nm laser.

Laser light activation of a second-generation photosensitiser and its use as a potential photomodulatory agent in skin rejuvenation

Photodynamic rejuvenation therapy (PDRT) is a growing field in cosmetic dermatology. In this study, different sources of light (a yellow laser, a red laser and ultraviolet A (UVA) lamps) were used to activate a second-generation photosensitiser, hypericin. Uptake of hypericin was monitored over 24 h and efficacy of PDRT was assessed using cell viability and reactive oxygen species (ROS) quantification assays. In addition, we show for the first time, a quantifiable assay for ROS production in human dermal fibroblasts incubated with hypericin and exposed to yellow laser light or UVA lamps. Furthermore, we optimised a protocol with regard to hypericin concentration and irradiation parameters using the XTT cell viability kit. This study showed that this photosensitiser, hypericin, was taken up by the cells in a concentration-dependent manner over 24 h with cell saturation occurring after approximately 16 h. The uptake seemed to be localised to the cell cytoplasm with no hypericin appearing in the nucleus. The levels of ROS increased in the cell when irradiated with the yellow laser (561 nm) however, it did not increase further with the addition of hypericin. Hypericin and UVA showed a significant increase in the amount of ROS produced. The results also show that cell viability is not affected by low power light (2 mW) from the yellow laser irrespective of the dose used. However, an increase to 10 mW power with 5 J/cm(2) light dose, resulted in a significant drop (p < 0.05) in cell viability at both 0.5 (77.53 ± 9.67 %) and 1 μM (48.51 ± 13.27 %) hypericin concentrations. In contrast, a 20 % increase in cell viability was seen with 1 J/cm(2) and 20 mW and 0.25 μM hypericin. Overall, this study highlights an optimised protocol for hypericin-induced photorejuvenative therapy using laser light and proposes that parameters of 0.25 μM hypericin as a photosensitiser activated via a dosage of 1 J/cm(2) yellow laser light produces an effective in vitro outcome to be considered as an important contribution towards optimising PDRT.

Treatment of hidradenitis suppurativa with intense pulsed light: a prospective study

BACKGROUND

Hidradenitis suppurativa is a chronic skin condition characterized by recurrent inflammation and infection of skin in intertriginous areas containing apocrine glands. Intense pulsed light uses high-energy broad-spectrum light. Current applications include hair removal and the treatment of acne vulgaris, which has a pathogenesis similar to that of hidradenitis suppurativa. The authors conducted a study to determine whether intense pulsed light is an effective treatment for hidradenitis suppurativa.

METHODS

Eighteen patients were randomized to treatment of one axilla, groin, or inframammary area with intense pulsed light two times per week for 4 weeks using a Harmony Laser. The contralateral side received no treatment and acted as a control. The response to treatment was assessed using a validated examination and clinical photographs, and by measuring patient satisfaction on a Likert scale.

RESULTS

After treatment, there was a significant improvement in the mean examination score that was maintained at 12 months (p < 0.001, logistical regression analysis). The improvement was confirmed by independent assessment of clinical photographs (interrater reliability, 0.79; p < 0.001). Patients reported high levels of satisfaction with the treatment. There was no concurrent improvement on the untreated control side.

CONCLUSIONS

This small study suggests that intense pulsed light may be an effective treatment for hidradenitis suppurativa. It could be added to treatments used for this condition, particularly for patients keen on avoiding surgery and those with groin and inframammary disease. Further studies are required to confirm the efficacy and mechanism of action of intense pulsed light in hidradenitis suppurativa.