Lesional Psoriasis is Associated With Alterations in the Stratum Corneum Ceramide Profile and Concomitant Decreases in Barrier Function.

Psoriasis is an inflammatory skin disease associated with an impaired skin barrier. The skin barrier function is dependent on the extracellular lipid matrix which surrounds the corneocytes in the stratum corneum. Ceramides comprise essential components of this matrix. Alterations in the stratum corneum ceramide profile have been directly linked to barrier dysfunction and might be an underlying factor of the barrier impairment in psoriasis. In this study, we investigated the ceramide profile and barrier function in psoriasis. Lesional and non-lesional skin of 26 patients and 10 healthy controls were analysed using in-depth ceramide lipidomics by liquid chromatography-mass spectrometry. Barrier function was assessed by measuring transepidermal water loss. Lesional skin showed a significant decrease in the abundance of total ceramides with significant alterations in the ceramide subclass composition compared to control and non-lesional skin. Additionally, the percentage of monounsaturated ceramides was significantly increased, and the average ceramide chain length significantly decreased in lesional skin. Altogether, this resulted in a markedly different profile compared to controls for lesional skin, but not for non-lesional skin. Importantly, the reduced barrier function in lesional psoriasis correlated to alterations in the ceramide profile, highlighting their interdependence. By assessing the parameters 2 weeks apart, we are able to highlight the reproducibility of these findings, which further affirms this connection. To conclude, we show that changes in the ceramide profile and barrier impairment are observed in, and limited to, lesional psoriatic skin. Their direct correlation provides a further mechanistic basis for the concomitantly observed impairment of barrier dysfunction.

Difference between hand and forearm transepidermal water loss and skin pH as an improved method to biomonitor occupational hand eczema: our findings in healthcare workers.

The aim of this cross-sectional field study was to establish the condition of hand and forearm skin barrier among dentists and physicians and how it may be associated with personal and work-related factors. The study consisted of an occupational questionnaire, clinical examination of skin on hands, and transepidermal water loss (TEWL) and pH measurements on hands and forearms. The participants were divided in the following groups (N=37 each, N=148 in total): physicians, medical surgeons, dentists, and dental surgeons. We calculated the difference between hand and forearm TEWL and pH (ΔTEWL and ΔpH, respectively) and divided it by the forearm values (ΔTEWL% and ΔpH%, respectively). There was a clear trend of increasing median ΔTEWL%, starting from physicians with non-surgical specialisation (56 %) to medical surgeons (65 %), dentists (104 %), and dental surgeons (108 %), with the latter two groups showing particularly worrisome signs of work-related skin barrier impairment, since they had double the TEWL on hands than on forearms. Although less prominent, the same worsening trend was noted for skin pH, with dental surgeons having on average a 0.3 points higher skin pH on hands than on forearms. These findings were mainly associated with prolonged glove use and male sex. Our findings also suggest that comparing TEWL and pH between hands and forearms can better establish occupational skin barrier impairment on hands.

Caloric restriction impacts skin barrier function and attenuates the development of hyperplasia skin disease.

Caloric restriction (CR) stands out as one of the most potent interventions that prolong lifespan and mitigate age-associated diseases. Despite its well-established systemic effects, the impact of CR on skin physiological function remains poorly understood, and whether the intervention can alleviate the progression of inflammatory skin diseases remains uncertain. Here, we investigated the effects of CR on mouse skin barrier function and inflammatory response. Our results revealed that CR led to dramatic atrophy in the skin subcutaneous layer. The expression of barrier proteins and trans-epidermal water loss remain largely unchanged. Intriguingly, skin from CR mice exhibited reduced expression of inflammatory cytokines under steady conditions. In an imiquimod (IMQ)-induced mouse model of psoriasis, CR treatment attenuated the pathogenesis of psoriasis phenotypes, accompanied by a reduced activation of mTOR signaling in the psoriatic skin. Taken together, our findings shed light on the complex interplay between metabolic interventions and skin health, suggesting that CR has the potential to serve as a modulator of inflammatory responses in the skin.

Tape Stripping Method in Dermatological and Pharmacological Research: Evaluating Fresh and Frozen-Thawed Porcine Skin.

Background The stratum corneum (SC) plays a crucial role in protecting the skin and regulating water loss. Tape stripping is a well-established method for studying skin barrier function and evaluating topical treatments. However, the behavior of fresh versus frozen-thawed skin during tape stripping has not been extensively compared. Objective This study aims to compare the removal of the stratum corneum from fresh and frozen-thawed porcine skin using tape stripping. It also aims to assess the reliability of tape weighing versus histological methods in quantifying SC removal. Methods Fresh and frozen-thawed porcine ears were obtained, cleaned, and subjected to tape stripping at varying numbers of strips from zero to 40. Tape weight and histological measurements were used to quantify SC removal. Statistical analyses were conducted to compare SC thickness and tape weight between the two types of skin. Results The study found that frozen-thawed skin exhibited a non-linear rate (r = 0.65) of SC removal per tape strip in the first five strips compared to a linear removal for fresh skin (r = 0.96). By the fifth tape strip, frozen-thawed samples had lost 80.6% of their SC, while fresh samples had only lost 33.5% (P < 0.03). Tape weighing and histological measurements showed strong correlations (r = 0.93 for fresh skin and r = 0.95 for frozen-thawed skin), indicating that tape weighing is a reliable alternative to histology for assessing SC removal on both sample types. Conclusions Fresh and frozen-thawed porcine skin respond differently to tape stripping, with frozen-thawed skin showing accelerated SC removal in the first five strips. The strong correlation between tape weighing and histological analysis supports the use of tape weighing as a practical tool for evaluating SC removal. These findings have implications for specimen selection and methodological standardization in dermatological and pharmacological research. Future research should explore alternative preservation and SC thickness measurement methods and their impact on tape stripping outcomes.

Umbelliferone alleviates impaired wound healing and skin barrier dysfunction in high glucose-exposed dermal fibroblasts and diabetic skins.

Skin wound healing is a complex process involving various cellular and molecular events. However, chronic wounds, particularly in individuals with diabetes, often experience delayed wound healing, potentially leading to diabetic skin complications. In this study, we examined the effects of umbelliferone on skin wound healing using dermal fibroblasts and skin tissues from a type 2 diabetic mouse model. Our results demonstrate that umbelliferone enhances several crucial aspects of wound healing. It increases the synthesis of key extracellular matrix components such as collagen I and fibronectin, as well as proteins involved in cell migration like EVL and Fascin-1. Additionally, umbelliferone boosts the secretion of angiogenesis factors VEGF and HIF-1α, enhances the expression of cell adhesion proteins including E-cadherin, ZO-1, and Occludin, and elevates levels of skin hydration-related proteins like HAS2 and AQP3. Notably, umbelliferone reduces the expression of HYAL, thereby potentially decreasing tissue permeability. As a result, it promotes extracellular matrix deposition, activates cell migration and proliferation, and stimulates pro-angiogenic factors while maintaining skin barrier functions. In summary, these findings underscore the therapeutic potential of umbelliferone in diabetic wound care, suggesting its promise as a treatment for diabetic skin complications. KEY MESSAGES: Umbelliferone suppressed the breakdown of extracellular matrix components in the skin dermis while promoting their synthesis. Umbelliferone augmented the migratory and proliferative capacities of fibroblasts. Umbelliferone activated the release of angiogenic factors in diabetic wounds, leading to accelerated wound healing. Umbelliferone bolstered intercellular adhesion and reinforced the skin barrier by preventing moisture loss and preserving skin hydration.

Recombinant filaggrin-2 improves skin barrier function and attenuates ultraviolet B (UVB) irradiation-induced epidermal barrier disruption.

The integrity of the skin barrier is essential for maintaining skin health, with the stratum corneum and filaggrin 2 (FLG-2) playing a key role. FLG-2 deficiency or mutation has been linked to diseases such as atopic dermatitis, while external stressors such as ultraviolet B (UVB) radiation further damage the epidermal barrier. This study investigated the effects of recombinant filaggrin (rFLG) on skin barrier function and UVB induced epidermal destruction. Cell experiments showed that 10 µg/mL of rFLG could increase the mobility of HaCaT cells from 20 % to 42 %, increase the epithelial resistance (TEER) value by about 2 times, and up-regulate the tight junction associated protein by about 2 times. In mouse models of UVB-induced epidermal barrier destruction, rFLG at concentrations of 0.5, 1, and 2 mg/mL showed effective cell uptake and skin penetration, alleviating erythema, and reducing skin thickness in mice by 1.5-3 times. Among them, 2 mg/mL of rFLG treatment restored the expression of tight junction proteins (LOR, ZO-1, and caspase-14), reduced collagen degradation, and reduced oxidative stress by normalizing serum hydroxyproline and superoxide dismutase levels. In addition, 2 mg/mL of rFLG inhibited UVB-induced upregulation of matrix metalloproteinases (MMP-3 and MMP-9) and reduced pro-inflammatory factors (IL-10, IL-1α, IL-6, and TNF-α) and apoptotic markers (P38, Bax, and Bcl-2) to normal levels. These findings suggested that rFLG effectively enhanced skin barrier integrity and mitigated UVB-induced epidermal barrier destruction, highlighting its potential as a therapeutic agent for diseases associated with skin barrier dysfunction.

Dihydroavenanthramide D Enhances Skin Barrier Function through Upregulation of Epidermal Tight Junction Expression.

Skin barrier dysfunction and thin epidermis are hallmarks of sensitive skin and contribute to premature aging. Avenanthramides are the primary bioactive components of colloidal oatmeal, a commonly used treatment to enhance skin barrier function. This study investigated the relationship between skin barrier function and epidermal characteristics and explored the potential of dihydroavenanthramide D (dhAvD), a synthetic avenanthramide, to improve the skin barrier. We observed a significant correlation between impaired skin barrier function and decreased epidermal thickness, suggesting that a weakened barrier contributes to increased sensitivity. Our in vitro results in HaCaT cells demonstrated that dhAvD enhances keratinocyte proliferation, migration, and tight junction protein expression, thereby strengthening the skin barrier. To mimic skin barrier dysfunction, we treated keratinocytes and full-thickness skin equivalents with IL-4 and IL-13, cytokines that are implicated in atopic dermatitis, and confirmed the downregulation of tight junction and differentiation markers. Furthermore, dhAvD treatment restored the barrier function and normalized the expression of key epidermal components, such as tight junction proteins and natural moisturizing factors, in keratinocytes treated with inflammatory cytokines. In the reconstructed human skin model, dhAvD promoted both epidermal and dermal restoration. These findings suggest that dhAvD has the potential to alleviate skin sensitivity and improve skin barrier function.

CERS1 is a Biomarker of Staphylococcus aureus Abundance and Atopic Dermatitis Severity.

BACKGROUND: Atopic dermatitis (AD) is an inflammatory skin condition characterized by widely variable cutaneous Staphylococcus aureus abundance that contributes to disease severity and rapidly responds to type 2 immune blockade (i.e., dupilumab). The molecular mechanisms regulating S. aureus levels between AD subjects remain poorly understood. OBJECTIVE: To investigate host genes that may be predictive of S. aureus abundance and correspond with AD severity. METHODS: Data derived from the NIH/NIAID-funded (NCT03389893 [ADRN-09]) randomized, double-blind, and placebo-controlled multicenter study of dupilumab in adults (n=71 subjects) with moderate-severe AD. Bulk RNA-sequencing of skin biopsies (n=57 lesional, 55 non-lesional) was compared to epidermal S. aureus abundance, lipidomics, and AD clinical measures. RESULTS: S. aureus abundance and ceramide synthase 1 (CERS1) expression positively correlated at baseline across both non-lesional (r=0.29, p=0.030) and lesional (r=0.41, p=0.0015) skin. Lesional CERS1 expression also positively correlated with AD severity (i.e., SCORing AD [SCORAD] r=0.44, p=0.0006) and skin barrier dysfunction (transepidermal water loss area under the curve [TEWL AUC] r=0.31, p=0.025) at baseline. CERS1 expression (forms C18:0-sphingolipids) was negatively associated with elongation of very long chain fatty acids (ELOVL6; C16:0→C18:0) expression and corresponded with a shorter chain length sphingolipid composition. Dupilumab rapidly reduced CERS1 expression (day 7) and ablated the relationship with S. aureus abundance and ELOVL6 expression by day 21. CONCLUSION: CERS1 is a unique molecular biomarker of S. aureus abundance and AD severity that may contribute to dysfunctional skin barrier and shorter chain sphingolipid composition through fatty acid sequestration as a maladaptive compensatory response to reduced ELOVL6.

Insights from Traditional Chinese Medicine for Restoring Skin Barrier Functions.

The skin barrier is essential for maintaining the body's internal homeostasis, protecting against harmful external substances, and regulating water and electrolyte balance. Traditional Chinese Medicine (TCM) offers notable advantages in restoring skin barrier function due to its diverse components, targets, and pathways. Recent studies have demonstrated that active ingredients in TCM can safely and effectively repair damaged skin barriers, reinstating their proper functions. This review article provides a comprehensive overview of the mechanisms underlying skin barrier damage and explores how the bioactive constituents of TCM contribute to skin barrier repair, thereby offering a theoretical framework to inform clinical practices.

Antibacterial and Antiallergic Effects of Three Tea Extracts on Histamine-Induced Dermatitis.

Atopic dermatitis (AD) is a persistent and recurrent inflammatory skin condition with a genetic basis. However, the fundamental reasons and mechanisms behind this phenomenon remain incompletely understood. While tea extracts are known to reduce histamine-induced skin allergies and inflammation, the specific mechanisms by which various types of Chinese tea provide their protective effects are still not fully elucidated. In this study, a model of skin itching induced by histamine is used to explore the functions and mechanisms of three types of tea extract (Keemun black tea (HC), Hangzhou green tea (LC), and Fujian white tea (BC)) in alleviating histamine-induced dermatitis. The components of three tea extracts are identified by UPLC-Q-TOF-MS, and we found that their main components are alkaloids, fatty acyls, flavonoids, organic acids, and phenols. The inhibitory effects of three types of tea extract on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in skin injury are investigated by MIC and flow cytometry. The three types of tea extract have an inhibitory effect on the growth of bacterial flora, with HC showing the best inhibitory activity. The effect of the three types of tea extract on histamine-induced dermatitis is also evaluated. Furthermore, itchy skin experiments, HE staining, toluidine blue staining, and immunohistochemical staining of mouse skin tissues were performed to determine the variations of scratching, epidermal thickness, mast cell number, IL-1ß, and NGF content after the administration of the tea extracts. The three types of tea extracts all alleviate and inhibit skin itching, epidermal hyperplasia, and allergic dermatitis. BC effectively alleviates epidermal hyperplasia caused by skin allergies, and LC significantly downregulates NGF. HC reduces histamine-induced mast cell infiltration and downregulates IL-1ß to alleviate skin itching. Consequently, tea emerges a potent natural product that can inhibit the growth of skin wound bacterial flora and exhibit skin repair effects on histamine-induced allergic dermatitis.

Molybdenum Nanoparticles Alleviate MC903-Induced Atopic Dermatitis-Like Symptoms in Mice by Modulating the ROS-Mediated NF-κB and Nrf2 /HO-1 Signaling Pathways.

Purpose: Atopic dermatitis (AD) is a chronic inflammatory skin condition that can affect individuals of all ages. Recent research has shown that oxidative stress plays a crucial role in the development of AD. Therefore, inhibiting oxidative stress may be an effective therapeutic approach for AD. Nano-molybdenum is a promising material for use as an antioxidant. We aimed to evaluate the therapeutic effects and preliminary mechanisms of molybdenum nanoparticles (Mo NPs) by using a murine model of chemically induced AD-like disease. Methods: HaCaT cells, a spontaneously immortalized human keratinocyte cell line, were stimulated by tumor necrosis factor-alpha /interferon-gamma after pre-treatment with Mo NPs. Reactive oxygen species levels, production of inflammatory factors, and activation of the nuclear factor kappa-B and the nuclear factor erythroid 2-related factor pathways were then evaluated. Mo NPs was topically applied to treat a murine model of AD-like disease induced by MC903, a vitamin D3 analog. Dermatitis scores, pruritus scores, transepidermal water loss and body weight were evaluated. AD-related inflammatory factors and chemokines were evaluated. Activation of the nuclear factor kappa-B and nuclear factor erythroid 2-related factor / heme oxygenase-1 pathways was assessed. Results: Our data showed that the topical application of Mo NPs dispersion could significantly alleviate AD skin lesions and itching and promote skin barrier repair. Further mechanistic experiments revealed that Mo NPs could inhibit the excessive activation of the nuclear factor kappa-B pathway, promote the expression of nuclear factor erythroid 2-related factor and heme oxygenase-1 proteins, and suppress oxidative stress reactions. Additionally, they inhibited the expression of thymic stromal lymphopoietin, inflammatory factors, and chemokines, thereby alleviating skin inflammation. Conclusion: Mo NPs present a promising alternative treatment option for patients with AD as they could address three pivotal mechanisms in the pathogenesis of AD concurrently.

Light-emitting diode irradiation at 590 nm combined with active substances modulates ultraviolet B radiation-induced keratinocyte inflammation.

To evaluate the efficacy of yellow light-emitting diode (LED) irradiation at 590 nm, alone or in combination with anti-inflammatory active substances against ultraviolet (UV)-induced inflammation in keratinocytes. HaCaT keratinocytes were pretreated with LED yellow light (590 nm) alone or in combination with an antiinflammatory active substance such as glycerophosphoinositol choline (GC), extract of grains of paradise (Aframomum melegueta Schum, AM), or a bisabolol and ginger root extract mixture (Bb-GE) before UVB irradiation. Following each treatment, we measured the levels of inflammatory mediators secreted by keratinocytes. HaCaT keratinocytes treated with UVB (300 mJ cm-²) and then cultured for 24 h exhibited significantly upregulated expression of proinflammatory factors, including interleukin (IL)-1α, prostaglandin E2 (PGE2), and IL-8. After pretreatment with 590 nm LED, UVB-induced inflammatory responses were significantly inhibited. Co-pretreatment with 590 nm LED irradiation and GC further inhibited the expression of IL-1α and IL-8. IL-8 expression was inhibited by co-pretreatment with 590 nm LED irradiation and AM, whereas PGE2 expression was inhibited by co-pretreatment with 590 nm LED irradiation and Bb-GE. Co-treatment with 590 nm LED irradiation and various active substances modulated UVB-induced inflammation in keratinocytes, suggesting the potential application of this approach to prevent damage caused by voluntary sun exposure in daily life.

Management of triggering factor effects in sensitive skin syndrome with a dermo-cosmetic product.

OBJECTIVE: Environmental factors are important in the generation or aggravation of sensitive skin syndrome (SSS). Creams can be useful for patients with SSS, particularly when triggering factors cannot be avoided. Several clinical studies have investigated the safety and efficacy of specific creams in patients with SSS, but the majority were assessed with a single type of triggering factor and were non-comparative. Therefore, this study's aim was to investigate, the benefit of a specific dermo-cosmetic product in response to physical and chemical factors in subjects with SSS. METHODS: Three clinical studies were performed on subjects presenting SSS. The physical impact was assessed in a stripping test, and in a randomized intra-individual study with a newly developed heat-cold stress model. To assess chemical factors, a capsaicin test on the nasolabial fold was performed. RESULTS: The product significantly reduced the increase in skin microcirculation caused by stripping after 30 min versus. The untreated condition (45.8% vs. 62.0%; p < 0.01). Immediately and at D28, the product induced a significant increase in skin hydration even after a heat-cold stress, while the overall score of unpleasant symptoms significantly decreased compared with the control (8.1 vs. 10.7 and 3.7 vs. 8.0, respectively; p < 0.01). Regarding chemical factors, a significant difference in the sensation intensity (p < 0.001) was observed after capsaicin stress, also in terms of the sensation duration due to the product application versus the control (192 s vs. 403 s; p < 0.001). CONCLUSION: These studies show that topical application of a dermo-cosmetic product can prevent unpleasant symptoms and improve the skin state in SSS exposed to physical and chemical triggering factors.

Protease-Activated Receptor 2 in inflammatory skin disease: current evidence and future perspectives.

Protease-activated receptor-2 (PAR2) is a class-A G protein-coupled receptor (GPCR) activated by serine proteases and is expressed by multiple tissues, including the skin. PAR2 is involved in the skin inflammatory response, promoting Th2 inflammation, delaying skin barrier repair, and affecting the differentiation of keratinocytes. It also participates in the transmission of itch and pain sensations in the skin. Increasing evidence indicates that PAR2 plays an important role in the pathogenesis of inflammatory skin diseases such as acne vulgaris, rosacea, psoriasis, and atopic dermatitis. Additional focus will be placed on potential targeted therapies based on PAR2. The Goal of this review is to outline the emerging effects of PAR2 activation in inflammatory skin disease and highlight the promise of PAR2 modulators.

Current Insights on Lipidomics in Dermatology: A Systematic Review.

Inflammatory dermatoses and lipid disturbances are interrelated, especially due to chronic inflammatory conditions. The study aimed to investigate recent findings about lipidomic and dermatologic diseases, as well as on the sampling techniques developed to study lipidomics in vivo and analytical and statistical approaches employed. A systematic review was designed using the search algorithm "(lipidomics) AND (skin OR dermatology OR stratum corneum OR sebum OR epidermis) following PRISMA guidelines. The literature search identified 1013 references and, finally, only 48 were selected, including a total of 2651 participants with a mean age of 34.13±16.28. The dermatological diseases evaluated were atopic dermatitis (AD), acne, psoriasis, hidradenitis suppurativa (HS) and other skin diseases. Sebutape® was the primary sampling technique for lipidomics research. Most of the studies performed untargeted profiling through liquid chromatography with tandem mass spectrometry (LC-MS/MS) statistically analyzed with Principal Component Analysis (PCA), Orthogonal Partial Least-Squares Discriminate Analysis (OPLS-DA), heatmap and volcano plot models. The most consulted databases were LIPIDMAPS® Structure Database (LMSD), MetaboAnalyst and Human Metabolome Database (HMDB). A large heterogeneity of lipidomic and lipid metabolism profiles was observed in patients with skin diseases. Skin lipidomic analysis is valuable in exploring skin disease and has ample translational potential.

Eczema Herpeticum: Clinical Insights and Pathogenesis Hypotheses on Basolateral Adhesion Proteins.

Eczema herpeticum (EH) is a severe viral complication caused by the herpes simplex virus (HSV) that occurs in individuals with compromised skin barriers, such as those with atopic dermatitis (AD). EH is characterized by the rapid spread of HSV across skin lesions, potentially leading to systemic involvement. Although commonly observed in the context of AD, EH can also arise in various dermatological conditions, necessitating prompt recognition and management by healthcare providers. This case report details the diagnosis and treatment of EH in a five-year-old girl with a history of AD who presents with fever and painful skin lesions. Despite the absence of confirmatory tests initially, a positive IgM anti-HSV-1 serology, combined with clinical presentation, supported the diagnosis of EH. The patient received intravenous aciclovir, resulting in significant improvement within 48 hours. This case highlights the importance of early diagnosis and treatment, particularly when confirmatory tests are not available. The report discusses the clinical presentation of EH, which includes vesicular lesions, fever, and rapid progression. The differential diagnosis includes chickenpox, impetigo, eczema vaccinatum, and contact dermatitis. Understanding the epidemiology and pathogenesis of EH, especially in relation to AD, is crucial for effective management. The case also introduces a novel hypothesis linking structural protein alterations to immune dysfunction in EH, suggesting a need for further research. Acyclovir remains the gold standard for treating EH, and timely intervention is essential. This case underscores the necessity of a diagnostic algorithm in the absence of guidelines and highlights the role of IgM serology and clinical judgment in managing suspected EH cases.

Development and characterization of topical formulation for maintenance therapy containing sorbitan monostearate with and without PEG-100-stearate.

OBJECTIVE: Basic therapy is an integral part of the treatment of chronic skin diseases. However, the formulation of skin products should be analysed with respect to the physical stability and tolerance by the patients before applying them to diseased skin. In particular, the suitability of the formulation for use on damaged skin should be taken into consideration so that no exacerbation of the condition is caused. METHODS: The following approach investigated two formulations with the emulsifier sorbitan monostearate and one with the addition of polyethylene glycol 100 stearyl ether. The characterization included rheology, macroscopic and microscopic cream analysis compared to marketed products for basic therapy. Pyranine staining of stratum corneum (SC) and trans-epidermal water loss (TEWL) measurements were performed with ex vivo porcine SC to asses skin barrier function. RESULTS: The rheological characterization showed a gel-like, viscoelastic behaviour of the formulations and a viscosity in the same order of magnitude as the marketed products. Staining with pyranine revealed that skin damage caused by sodium lauryl sulfate was compensated by treatment with the developed formulations. Following the same trend, TEWL results clearly showed decreasing values, which evidence improved skin barrier function. CONCLUSION: In conclusion, the developed sorbitan monostearate formulations can potentially improve deficient skin barrier function as a part of basic therapy of skin diseases and act as a superior alternative to market products comprising a minimum of well-chosen ingredients.

OBJECTIF: la thérapie de base fait partie intégrante du traitement des maladies chroniques de la peau. Cependant, la formulation des produits pour la peau doit être analysée en termes de stabilité physique et de tolérance par les patients avant de les appliquer sur la peau malade. En particulier, il convient de prendre en compte l'adéquation de la formulation à être utilisée sur une peau lésée afin d'éviter toute exacerbation de l'affection. MÉTHODES: l'approche suivante a étudié deux formulations avec l'émulsifiant monostéarate de sorbitane et une autre avec l'ajout d'éther de stéaryle de polyéthylène glycol 100. La caractérisation comprenait la rhéologie, l'analyse macroscopique et microscopique de la crème par rapport aux produits commercialisés pour la thérapie de base. Une coloration à la pyranine de la couche cornée et des mesures de la perte d'eau transépidermique ont été effectuées avec des couches cornées ex vivo de porc pour évaluer la fonction de barrière cutanée. RÉSULTATS: la caractérisation rhéologique a montré un comportement viscoélastique de type gel des formulations et une viscosité du même ordre de grandeur que les produits commercialisés. La coloration à la pyranine a révélé que les lésions cutanées causées par le laurylsulfate de sodium étaient compensées par le traitement avec les formulations développées. Suivant la même tendance, les résultats de la perte d'eau transépidermique ont clairement montré des valeurs en baisse, ce qui témoigne de l'amélioration de la fonction de barrière cutanée. CONCLUSION: en conclusion, les formulations de monostéarate de sorbitane développées peuvent potentiellement améliorer la fonction de barrière cutanée déficiente dans le cadre d'une thérapie de base des maladies de la peau et constituer une alternative supérieure.

The effect of degeneration of elastic fibres on loss of elasticity and wrinkle formation.

OBJECTIVE: Skin elasticity, which is vital for a youthful appearance, depends on the elastic fibres in the dermis. However, these fibres deteriorate with ageing, resulting in wrinkles and sagging. Changes that occur in the elastic fibres in living human skin and the relationship between elastic fibres and the state of the skin surface remain unclear. Therefore, it is necessary to verify the relationship between elastic fibres and skin elasticity. In this study, we investigated the association of the elastic fibre structure with skin elasticity and stratum corneum protein content in living human skin. METHODS: Thirty-five female volunteers aged 25-66 years were included in this study. Elastic fibres were observed using a multiphoton scanning laser biomicroscope. Skin elasticity was measured using a Cutometer, and stratum corneum proteins (Heat-shock protein 27 [HSP27] and galectin-7 [Gal-7]) in tape-stripped samples were analysed using an enzyme-linked immunosorbent assay. RESULTS: Elastic fibres exhibited increased curvature and thickness with increased age, with fragmentation observed in women aged >60 years. Elastin scores, which reflect thinness and curvature, were negatively correlated with age, whereas they were positively correlated with R7 elasticity (recovery ability). In individuals aged 20-30 years, higher levels of inflammatory markers (HSP27 and Gal-7) correlated with lower elastin scores; however, this trend was not observed in older participants. CONCLUSION: Elastic fibre deterioration worsened after 40 years of age, and this effect correlated with reduced skin recovery and increased wrinkles. In younger individuals, inflammatory markers affected elastic fibres. These findings can guide anti-ageing strategies that focus on elastic fibre preservation and inflammation control.

OBJECTIF: L'élasticité de la peau, vitale pour un aspect jeune, dépend des fibres élastiques du derme. Cependant, ces fibres se détériorent avec l'âge, ce qui entraîne des rides et un affaissement. Les changements qui se produisent dans les fibres élastiques de la peau humaine vivante et la relation entre les fibres élastiques et l'état de la surface de la peau restent peu clairs. Il est donc nécessaire de vérifier la relation entre les fibres élastiques et l'élasticité de la peau. Dans cette étude, nous avons étudié l'association de la structure des fibres élastiques avec l'élasticité de la peau et la teneur en protéine de la couche cornée dans une peau humaine vivante. MÉTHODES: 35 volontaires de sexe féminin âgés de 25 à 66 ans ont été inclus dans cette étude. Des fibres élastiques ont été observées à l'aide d'un biomicroscope à balayage laser multiphotonique. L'élasticité de la peau a été mesurée à l'aide d'un cutomètre, et les protéines de la couche cornée (les protéines de choc thermique 27 [Heat­shock protein 27, HSP27] et galectine­7 [Gal­7]) dans des échantillons avec bande adhésive ont été analysées à l'aide d'un dosage par la méthode immuno­enzymatique ELISA. RÉSULTATS: Les fibres élastiques présentaient une courbure et une épaisseur accrues avec l'âge, avec une fragmentation observée chez les femmes âgées de >60 ans. Les scores d'élastine, qui reflètent la minceur et la courbure, étaient corrélés négativement avec l'âge, tandis qu'ils étaient corrélés positivement avec l'élasticité de R7 (capacité de récupération). Chez les personnes âgées de 20 à 30 ans, des taux plus élevés de marqueurs inflammatoires (HSP27 et Gal­7) étaient corrélés avec une diminution des scores d'élastine; toutefois, cette tendance n'a pas été observée chez les participants plus âgés. CONCLUSION: La détérioration des fibres élastiques s'est aggravée après l'âge de 40 ans, et cet effet était corrélé à une récupération réduite de la peau et à une augmentation des rides. Chez les personnes plus jeunes, les marqueurs inflammatoires ont affecté les fibres élastiques. Ces résultats peuvent orienter les stratégies anti­âge qui se concentrent sur la préservation des fibres élastiques et le contrôle de l'inflammation.

Investigation of keratolytic impact of synthetic bolalipids on skin penetration of a model hydrophilic permeant.

Synthetic single-chain bolalipids (SSCBs) are novel excipients in drug delivery, with potential as stabilizers or solubilizers. However, their impact on skin barrier function has not been comprehensively studied. Therefore, two SSCBs (PC-C24-PC and PC-C32-PC) were studied in aqueous systems for their impact on penetration of a model permeant into porcine skin. Concentrations of 0.05 - 5 % w/w were tested; PC-C24-PC formulations were low-viscosity liquids while PC-C32-PC formed viscous dispersions to gels at room temperature. Formulations were compared for their ability to enhance sodium fluorescein penetration (SF, 0.1 % w/w) into skin via tape stripping. Using NIR-densitometry, the effect of SSCB formulations on corneocyte cohesion was evaluated. Data were compared with phospholipid mixture Lipoid S-75, sodium dodecyl sulfate (SDS), and polyethylene glycol 12-hydroxystearate (PEG-HS), and distilled water as negative control. Contrary to the hypothesis, both SSCBs failed to increase SF penetration into the stratum corneum, but rather showed a significant decrease in penetration depth compared to water. Both SSCBs exhibited a keratolytic effect at 5 % w/w, leading to substantial removal of proteins from the skin surface. Consequently, SSCBs may not enhance penetration of hydrophilic drugs into skin, but could be used as keratolytic agents.