Intense Pulsed Light Effects on the Expression of Extracellular Matrix Proteins and Transforming Growth Factor Beta-1 in Skin Dermal Fibroblasts Cultured within Contracted Collagen Lattices

Characterization and mechanism of action of amphibian-derived wound-healing-promoting peptides

Wound-healing-promoting peptides are excellent candidates for developing wound-healing agents due to their small size and low production cost. Amphibians are one of the major sources of bioactive peptides, including wound-healing-promoting peptides. So far, a series of wound-healing-promoting peptides have been characterized from amphibians. We hereby summarized the amphibian-derived wound-healing-promoting peptides and their mechanism of action. Among these peptides, two peptides (tylotoin and TK-CATH) were characterized from salamanders, and twenty five peptides were characterized from frogs. These peptides generally have small sizes with 5-80 amino acid residues, nine peptides (tiger17, cathelicidin-NV, cathelicidin-DM, OM-LV20, brevinin-2Ta, brevinin-2PN, tylotoin, Bv8-AJ, and RL-QN15) have intramolecular disulfide bonds, seven peptides (temporin A, temporin B, esculentin-1a, tiger17, Pse-T2, DMS-PS2, FW-1, and FW-2) are amidated at the C-terminus, and the others are linear peptides without modifications. They all efficiently accelerated the healing of skin wounds or photodamage in mice or rats. They selectively promoted the proliferation and migration of keratinocytes and fibroblasts, recruited neutrophils and macrophages to wounds, and regulated the immune response of neutrophils and macrophages in wounds, which were essential for wound healing. Interestingly, MSI-1, Pse-T2, cathelicidin-DM, brevinin-2Ta, brevinin-2PN, and DMS-PS2 were just antimicrobial peptides, but they also significantly promoted the healing of infected wounds by clearing off bacteria. Considering the small size, high efficiency, and definite mechanism, amphibian-derived wound-healing-promoting peptides might be excellent candidates for developing novel wound-healing-promoting agents in future.

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.

Analysis of Cytokine Levels in Tears and Clinical Correlations After Intense Pulsed Light Treating Meibomian Gland Dysfunction

PURPOSE

To investigate the change from baseline of inflammatory markers in tears of dry eye disease (DED) subjects owing to meibomian gland dysfunction (MGD) after intense pulsed light (IPL) treatment and meibomian gland expression (MGE) compared to sham treatment, and the correlations with ocular surface parameters.

DESIGN

Randomized, double-masked, controlled study.

METHODS

Those randomized into the active treatment arm received 3 consecutive treatments (14∼16 J/cm²) approximately 4 weeks apart in the periocular region. Control eyes received 3 treatments in the same intervals of 0 J/cm². Tear samples in all eyes were collected and analyzed at baseline, week 12, and/or week 4 for interleukin (IL)-17A, IL-6, and prostaglandin E2 (PGE2). The correlations between cytokines and ocular surface parameters were analyzed before and after IPL treatment.

RESULTS

All of the inflammatory markers declined in value compared to baselines. IL-17A and IL-6 showed statistically significant decreases compared to sham treatment at each measured time point. PGE2 showed statistically significant decreases compared to sham at week 12. Results showed that the expressions of IL-17A and IL-6 correlated well with ocular surface parameters of the lower eyelid before IPL. The changed values of IL-6 and PGE2 in tears correlated with the changed values of partial ocular surface parameters after IPL treatment in study eyes, respectively.

CONCLUSIONS

The study results suggest that IPL can significantly reduce inflammatory markers in tears of patients suffering with DED owing to MGD after IPL treatment. These findings indicate that IL-17A and IL-6 play roles in the pathogenesis of DED owing to MGD, and the reduction of the inflammatory factors is consistent with the improvement of partial clinical symptoms and signs.

In vitro studies to evaluate the effect of varying culture conditions and IPL fluencies on tenocyte activities

Tendons are dense, fibrous connective tissues which carry out the essential physiological role of transmitting mechanical forces from skeletal muscle to bone. From a clinical perspective, tendinopathy is very common, both within the sporting arena and amongst the sedentary population. Studies have shown that light therapy may stimulate tendon healing, and more recently, intense pulsed light (IPL) has attracted attention as a potential treatment modality for tendinopathy; however, its mechanism of action and effect on the tendon cells (tenocytes) is poorly understood. The present study therefore investigates the influence of IPL on an in vitro bovine tendon model. Tenocytes were irradiated with IPL at different devise settings and under variable culture conditions (e.g. utilising cell culture media with or without the pH indicator dye phenol red), and changes in tenocyte viability and migration were subsequently investigated using Alamar blue and scratch assays, respectively. Our data demonstrated that IPL fluencies of up to 15.9 J/cm² proved harmless to the tenocyte cultures (this was the case using culture media with or without phenol red) and resulted in a significant increase in cell viability under certain culture conditions. Furthermore, IPL treatment of tenocytes did not affect the rate of cell migration. This study demonstrates that irradiation with IPL is not detrimental to the tenocytes and may increase their viability under certain conditions, thus validating our in vitro model. Further studies are required to elucidate the effects of IPL application in the clinical situation.

The Efficacy of Intense Pulsed Light Therapy in Postoperative Recovery from Eyelid Surgery

BACKGROUND

The purpose of this study was to evaluate the efficacy of postoperative intense pulsed light therapy on patients who undergo bilateral eyelid surgery.

METHODS

Patients presenting over a 3-month period for bilateral eyelid surgery were asked to participate in an institutional review board-approved study. Intense pulsed light therapy was administered three times to the same randomly assigned side on postoperative days 1 to 2, 5 to 7, and 10 to 12. Sham light therapy was administered to the contralateral side. Patient surveys and physician ratings were obtained based on photographic evaluation of ecchymosis, edema, and erythema. Three physicians, including the senior author (A.E.W.), submitted ratings, and these ratings were assessed for interobserver reliability.

RESULTS

Twenty-eight patients who underwent bilateral eyelid surgery followed by intense pulsed light therapy were enrolled. The mean age of the patients was 66 years (range, 44 to 81 years). Eighty-six percent of patients were female. The change in ratings between postoperative days 1 to 2 and 10 to 12, in the treatment and control groups, was statistically significant for severity of bruising by both patient and physician assessment and for color of bruising only by patient assessment. The interobserver reliability reached the greatest agreement in the ecchymosis category at each time point for the treatment group.

CONCLUSION

In a series of patients who underwent eyelid surgery, intense pulsed light therapy decreased the degree of ecchymosis compared with sham treatment in postoperative eyelid surgery patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

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.

Intense pulsed light enhances transforming growth factor beta1/Smad3 signaling in acne-prone skin

BACKGROUND

Recently, much interest has been generated in the use of intense pulsed light (IPL) sources in the treatment of various skin conditions. However, the underlying mechanism for its therapeutic action has not been elucidated.

OBJECTIVE

To investigate the effect of IPL on the in vivo expression of transforming growth factor beta1 (TGF-β1) and on the immunolocalization of Smad3 in biopsies obtained from perilesional skin in patients with mild-to-moderate inflammatory acne vulgaris.

METHODS

Biopsies obtained from 20 patients with inflammatory acne vulgaris at baseline (B1) and post-IPL treatment (B2 = 48 h after first treatment and B3 = 1 week after final treatment) were immunohistochemically analyzed to determine the expression of TGF-β1 and the immunolocalization of Smad3. Digital images were semiquantitatively assessed using image analysis software.

RESULTS

Intense pulsed light elicited a consistent increase in epidermal TGF-β1 expression (B2 vs. B1: P = 0.004 and B3 vs. B1: P = 0.007). Furthermore, it resulted in enhanced nuclear immunolocalization of Smad3 (B2 vs. B1: epidermis, P = 0.000055 and dermis, P = 0.014; B3 vs. B1: epidermis, P = 0.00024 and dermis, P = 0.008).

CONCLUSION

Intense pulsed light upregulates TGF-β1/Smad3 signaling in perilesional skin obtained from patients with mild-to-moderate inflammatory acne vulgaris. Further experiments on lesional skin and downstream effects are warranted to determine whether it may play a role in IPL-induced resolution of acne vulgaris.

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.

Effect of intense pulsed light on rat skin

BACKGROUND

Intense pulsed light (IPL) is widely used in treating skin conditions and has been reported to increase collagen and elastic fibers without damaging the epidermis.

OBJECTIVE

To evaluate the effect of variation in the number of passes and intervals of IPL treatments on photorejuvenation in rats.

MATERIALS AND METHODS

Groups of two rats each were exposed to two or four passes of an IPL source using a fluence of 30 J/cm(2) and a cut-off filter of 560 nm at 1- or 3-week intervals. The collagen and elastic fiber content in stained tissue biopsies and the thickness of the collagen fibers of IPL-irradiated and unexposed skin regions were compared.

RESULTS

Collagen distribution and collagen fiber diameter was in IPL-irradiated than in control regions. The number of passes did not significantly affect the collagen fiber thickness, but the collagen fibers from the 3-week-interval groups were thicker than those of the 1-week-interval groups (p < .001).

CONCLUSION

IPL increased dermal collagen fibers and collagen fiber diameter, suggesting efficacy in photorejuvenation and wrinkle reduction.

Exploring the role of a nonablative laser (1320 nm cooltouch laser) in skin photorejuvenation

BACKGROUND

Nonablative laser has been used for the treatment and prevention of skin aging for many years. Although the mechanism has not been elucidated, histological evaluation showed that the dermal fibroblasts and its collagen production should be the main target for this rejuvenation. In order to determine the effects of a 1320 nm nonablative laser on the human dermal fibroblasts, the two main secretion factors, basic fibroblast growth factor (bFGF) and transforming growth factor β1(TGF-β1), in vitro were detected.

METHODS

The human dermal fibroblasts were cultured and irradiated with a 1320 nm laser at the dose of 15, 20, and 24 J/cm(2) respectively. The number of fibroblasts was counted and the levels of bFGF and TGF-β1 were detected by enzyme-linked immunosorbent assay at the time points of 0, 24, 48, and 72 h after irradiation.

RESULTS

The results showed that both the number of fibroblasts and the secretion of bFGF increased after the irradiation at the dose of 20 and 24 J/cm(2) (P<0.05) compared with that of the control cells. The bFGF secretion in the group exposed to 20 J/cm(2) was more significant than that of 24 J/cm(2), and the peak level was 24 h after irradiation. The level of TGF-β1 secretion decreased after irradiation in a dose-dependent manner (15 and 20 J/cm(2), both P<0.05; 24 J/cm(2), P<0.01), and reached a nadir at 24 h.

CONCLUSION

Our results suggested that the 1320 nm nonablative laser accelerates the vitality of fibroblasts, promotes the secretion of bFGF, and inhibits TGF-β1 secretion by fibroblasts.