Impaired Skin Barrier Function Research Articles

ALLERGIC CONTACT DERMATITIS AND ATOPIC DERMATITIS: HIGHLIGHTS OF THE OVERLAP SYNDROME

Introduction. The combination of atopic dermatitis (AD) with allergic contact dermatitis (ACD) or the occurrence of ACD on the background of atopic dermatitis is called the overlap syndrome. Studies have demonstrated several reasons why patients with AD have a similar or even increased risk of developing ACD compared to those without AD. Allergens and haptens are trigger factors in a group of patients with AD and ACD overlap syndrome. The aim of the study. To confirm the diagnosis of ACD in a group of patients with AD – diagnose the overlap syndrome and analyze which allergens and haptens were the trigger factors in this group. Materials and methods. To confirm IgE-dependent sensitization in atopic dermatitis, skin prick tests or determination of specific IgE in blood serum were performed. Skin patch tests (European series S-1000) were performed to determine the mechanisms of delayed-type hypersensitivity. Results. It was found that the highest specific weight of positive allergic reactions has been recorded in response to the following allergens: ticks, ticks/ambrosia, birch and mold. The absolute majority of patients demonstrated positive specific IgE-dependent sensitization to Dermatophagoides pteronyssinus and Dermatophagoides farinae – 24 (50%), in turn, on Ambrósia – 14 (29.2%), and on Alternaria alternata – 8 (16.7%). Also, the reaction was most often recorded to haptens: cobalt, nickel, formaldehyde, PPD, textile dyes. Deterioration of the clinical course and shortening of AD remission periods were observed due to the formation of ACD against the background of impaired skin barrier function and the presence of chronic immune inflammation. Conclusions. Patients with AD are more often diagnosed with ACD, which predictably worsens the course of AD. Patients with confirmed overlap syndrome "AD + ACD" most often show reactions to haptens: Cobalt, Nikel, Formaldehyde, PPD, Textile dye mix – and in the vast majority to 2 haptens or more in one patient.

A Novel Recombinant Human Filaggrin Segment (rhFLA-10) Alleviated a Skin Lesion of Atopic Dermatitis.

Atopic dermatitis (AD), a prevalent chronic inflammatory skin disorder, is marked by impaired skin barrier function and persistent pruritus. It significantly deteriorates patients' quality of life, making it one of the most burdensome non-lethal skin disorders. Filaggrin plays a crucial role in the pathophysiology of barrier disruption in AD, interacting with inflammatory mediators. It is an integral part of the extracellular matrix architecture, serving to protect the skin barrier and attenuate the inflammatory cascade. In this study, we engineered a novel recombinant human filaggrin (rhFLA-10) expression vector, which was subsequently synthesized and purified. In vitro and ex vivo efficacy experiments were conducted for AD. rhFLA-10, at low concentrations (5 to 20 μg/mL), was non-toxic to HACaT cells, significantly inhibited the degranulation of P815 mast cells, and was readily absorbed by cells, thereby exerting a soothing therapeutic effect. Furthermore, rhFLA-10 demonstrated anti-inflammatory properties (p < 0.05). In vivo, efficacy experiments further substantiated that rhFLA-10 could effectively ameliorate AD in mice and facilitate the repair of damaged skin (p < 0.001). These findings underscore the considerable potential of rhFLA-10 in the treatment of AD.

The effectiveness of ceramide moisturizing cream in pruritic papular eruption treatment of HIV/AIDS patients

Background: Pruritic papular eruption (PPE) is one of the most common skin manifestations in HIV/AIDS patients. Pruritic papular eruptions are due to immune dysregulation, causing dominance of interleukin-4, which causes a decrease in ceramide synthesis (CER) and impaired skin barrier function. This study aimed to investigate the effectiveness of CER over non-CER moisturizing cream in HIV/AIDS patients with PPE. Methods: Double-blind experimental design. The research subjects are PPE patients at Dr. Sardjito General Hospital. CER and non-CER moisturizing cream are applied for three weeks, respectively. Analysis of the trans-epidermal water loss (TEWL), skin hydration, and itching were analyzed using an unpaired T-test or the Mann-Whitney test with a significance of p&lt;0.05. Results: Ceramide synthesis moisturizing cream decreased the TEWL value by 3.56 ± 2.38 g/m2/hour; increased the value of skin hydration by 16.39±7.19 a.u.; decreased skin lesions by 0.79 ± 4.95; reduced itching by 1.54 ± 0.78 and without causing side effects. Non-CER moisturizing cream decreased the TEWL value by 1.57 ± 2.00 g/m2/hour; increased the value of skin hydration by 12.03 ± 6.88 a.u.; decreased skin lesions by 1.42 ± 3.00; reduced itching by 1.17 ± 0.70 and also without causing side effects. Conclusion: Ceramide cream is more effective than non-CER moisturizing cream in reducing TEWL and increasing skin hydration. Ceramide and non-CER moisturizing creams have the same effectiveness in reducing the number of lesions and reducing itching. Ceramide and non-CER moisturizing creams do not cause side effects.

Modern realities of correction of skin barrier disorders in various diseases

Skin xerosis is a common symptom that indicates of impaired skin barrier function. Such diseases as atopic dermatitis (AD) and ichthyosis are associated with genetic mutations of epidermal differentiation genes, while in other diseases (contact dermatitis, eczema) epidermal barrier disorders occur as a result of inflammatory process in the skin, mechanical or chemical damage, significantly affecting the course of the pathological process. The article highlights modern data on the importance of the main structural protein of the stratum corneum filaggrin (FLG) and the role of its deficiency not only in dermatologic diseases, but also in the development of hyperresponsiveness. The main methods of correction of skin barrier disorders are emollients, which belong to the methods of basic therapy in AD and are recommended for the complex therapy of other pathological conditions accompanied by xerosis. At the present time, an innovative method has been developed, that allows not only to replace FLG deficiency, but also to activate and stimulate protein synthesis in the skin. In this regard, a unique dermatocosmetics product “Admera”, which belongs to the category of “emollients plus” due to the combination of all the necessary properties of the emollient and the presence of FLG synthesis modulator filagrinol, is of interest. Filagrinol is a proprietary complex of active ingredients that activate enzymes involved in dephosphorylation of the FLG predecessor profilaggrin and increase the concentration in the stratum granulosum сells of a histidine-rich glycoprotein, involved in the formation of the stratum corneum cytoskeleton. The article presents a review of clinical studies on the efficacy of Admera cream and presents our own clinical experience of its use in patients with AD and hand eczema.

Harlequin Ichthyosis – Genetic and Dermatological Challenges: A Case Report and Literature Review

Harlequin ichthyosis (HI) is an extremely rare and severe genetic skin disorder characterized by thick, diamond-shaped scales covering the body, often giving the appearance of a harlequin costume. This paper provides an overview of the genetic and dermatological aspects of HI, delving into its etiology, clinical manifestations, and management. The genetic underpinnings of HI involve mutations in the ABCA12 gene, leading to impaired skin barrier function and abnormal keratinization. Understanding the molecular basis of the disorder is crucial for accurate diagnosis and potential therapeutic interventions. Clinically, HI presents challenges related to skin integrity, thermoregulation, and potential complications, such as infections. The management of HI requires a multidisciplinary approach involving dermatologists, geneticists, and other healthcare professionals. Supportive care, including emollients, careful bathing, and prevention of infections, is essential to improve the quality of life for individuals affected by this condition. Despite its rarity and severity, advancements in medical research and genetic therapies offer hope for improved treatments and interventions. This paper aims to contribute to the collective understanding of HI, fostering ongoing research and compassionate care for those living with this unique and challenging dermatological condition. We presented a premature eutrophic harlequin baby, born at 32+ weeks of gestation via emergency C-section. A clinical diagnosis was established minutes after birth, based on the typical features of HI, from scaly skin, marked fissures, and limbs in flexion contractures to prominent eclabium and bilateral ectropion.

Evaluation of the anti-aging effects of Zinc-α2-glycoprotein peptide in clinical and in vitro study.

Skin aging, characterized by the deterioration of skin density and elasticity, is a common concern among individuals seeking to maintain a youthful appearance. Zinc-α2-glycoprotein (ZAG) is secreted by various body fluids, and is associated with lipolysis and identified as an atopic dermatitis biomarker. This study evaluated the potential of ZAG peptides, which exert multiple benefits such as anti-aging. We conducted a 4-week clinical trial on patients with noticeable periorbital wrinkles (n=22) using a ZAG peptide-containing product. The effects of the products on skin density, elasticity, and the depth of periorbital wrinkles were evaluated using Cutometer Dual MPA580, Ultrascan, and Antera 3D CS, respectively. The effect of ZAG peptides on UVB-treated keratinocyte cells was evaluated in vitro to understand the mechanisms underlying its effects against impaired skin barrier function, collagen degradation, and senescence. In addition, the effects of ZAG peptides on cell viability and expression of aging and skin barrier-related genes were assessed using cell counting kit assay and quantitative reverse transcription-polymerase chain reaction, respectively. The patients demonstrated improved skin density, elasticity, and reduced periorbital wrinkles. Further, more than 85% patients scored the product as satisfactory regarding anti-aging effects. Furthermore, ZAG peptides reduced SA-β-gal staining, downregulated the senescence-related genes, and upregulated the skin barrier function-related genes in UVB-irradiated keratinocyte cells. Our clinical and in vitro findings showed that ZAG peptides exert anti-aging effects and improve skin barrier functions, suggesting their promising potential as therapeutic agents to combat skin aging and improve skin health.

Association between filaggrin gene mutations and the clinical features of molluscum contagiosum: The Yamanashi Adjunct Study of the Japan Environment and Children's Study.

Previous studies have reported swimming, atopic dermatitis, and filaggrin (FLG) gene mutations as risk factors for molluscum contagiosum (MC) infection. FLG gene mutations impair skin barrier function. The aim of this study was to determine the impact of FLG mutations on the incidence and clinical features of MC. We used data from 2036 children who participated in the Yamanashi Adjunct Study of the Japan Environment and Children's Study, a prospective, birth cohort study. A questionnaire for caregivers (when children were 4 and 8 years of age) asked about clinical features including previous MC incidence and treatment, number of MC lesions at first visit, and time to resolution. Participants underwent genotyping to detect six FLG mutations that are common in the Japanese population. A logistic regression model was used to analyze the association between MC incidence and FLG mutations, adjusted for potential confounders. The cumulative incidence of MC at age 8 years was 47.1%. Among participants with a history of MC, 67.6% had undergone curettage. FLG mutation was a significant risk factor for MC incidence (adjusted odds ratio [aOR] 1.69, 95% confidence interval [CI] 1.18-2.42). Swimming and atopic dermatitis were also significant risk factors for MC. There was no significant association between FLG mutation and the number of MC lesions at the first visit or the time to resolution of lesions. FLG mutation is a risk factor for MC incidence; however, FLG mutations do not affect the number of MC lesions at presentation or the time to resolution.

563 - Dupilumab improves skin lipid composition in atopic dermatitis irrespective of patient filaggrin (FLG) mutation status

Abstract Introduction/Background Type 2 inflammatory cytokines interleukin 4 (IL-4) and IL-13 play an important role in skin barrier disruption in atopic dermatitis (AD). Filaggrin and ceramides play a crucial role in skin barrier integrity. Loss of function mutations in the FLG gene are associated with the impaired skin barrier function and more severe AD.1,2 FLG mutations only affect a minority of AD patients; however, increased IL-4 and IL-13 cytokines are a common cause of reduced filaggrin expression in patients with AD, independent of FLG genotype. Objectives To explore whether dupilumab treatment improves skin barrier function in patients with or without FLG mutations. Methods In the BArrier function and LIpidomics STudy in Atopic Dermatitis (BALISTAD; NCT04447417), a 16-week study in patients with AD aged 12 to 65 years, adult patients with AD received dupilumab 300 mg every 2 weeks; adolescent patients with AD received dupilumab 200 mg every 2 weeks if their baseline weight was &amp;lt;60 kg and 300 mg if ≥60 kg. FLG mutations were evaluated in DNA from blood samples of consenting patients with AD and healthy volunteers. Transepidermal water loss (TEWL) was assessed longitudinally after 5 skin tape strippings (STS) from AD lesions (n = 26) and from the skin of healthy participants (n =26) (age: 12 to 63 years) over a 16-week course of dupilumab treatment. Quantitative N(C18)S-ceramide analysis of STS samples collected on Days 1, 15, 29, 57, and 85, and at Week 16 from AD lesions and from the skin of healthy participants was performed using liquid chromatography tandem mass spectrometry. Results At baseline, mean TEWL after 5 STS (TEWL5) was significantly higher in AD lesional skin than healthy skin (p&amp;lt;0.0001). The mean TEWL5 in AD lesions in subjects with FLG mutations (n = 6/19) was significantly higher at baseline than in AD subjects without mutations (P &amp;lt; 0.0001). Dupilumab treatment significantly reduced TEWL5 in AD lesional skin as early as Week 2 with a progressive decrease through Week 16 (P &amp;lt; 0.0001). Reduction in mean TEWL5 was similar from Week 2 to Week 16 in AD patients with and without FLG mutations. At Week 16, TEWL5 was comparable to healthy skin in the lesional skin of AD patients with and without FLG mutations (P &amp;gt; 0.05). AD skin lesions had increased levels of N(C18)S-ceramides at baseline (P &amp;lt; 0.0001); but no differences were noted in subjects with or without FLG mutations (P &amp;gt; 0.05). Dupilumab treatment significantly reduced levels of N(C18)S-ceramides in AD lesional skin as early as Week 2 with a progressive decrease through Week 16 (P &amp;lt; 0.0001). Dupilumab treatment decreased levels of N(C18)S-ceramides in STS samples similarly in subjects with and without FLG mutations from Week 2 to Week 16. Conclusions Dupilumab treatment normalizes TEWL5 and decreases levels of N(C18)S-ceramides in AD lesional skin of subjects with and without FLG mutations.

Infant lung function and early skin barrier impairment in the development of asthma at age 3 years.

Largely unexplored, we investigated if lower lung function, impaired skin barrier function by transepidermal water loss (TEWL), eczema, and filaggrin (FLG) mutations in infancy were associated with asthma in early childhood. From the factorially designed randomized controlled intervention study PreventADALL, we evaluated 1337/2394 children from all randomization groups with information on asthma at age 3 years, and at age 3 months either lung function, TEWL, eczema, and/or FLG mutations. Lower lung function was defined as the time to peak tidal expiratory flow to expiratory time (tPTEF /tE ) <0.25, and skin barrier impairment as a high TEWL >9.50 g/m2 /h. Eczema was clinically observed, and DNA genotyped for FLG mutations. Asthma was defined as asthma-like symptoms (≥3 episodes of bronchial obstruction) between age 2-3 years as well as a history of doctor-diagnosed asthma and/or asthma medication use. Associations were analyzed in logistic regression models, presented with adjusted ORs (aOR) and 95% confidence intervals (CI). Lower lung function and skin barrier impairment were associated with asthma in general; aOR (95% CI) 5.4 (2.1, 13.7) and 1.6 (1.1, 2.5), while eczema and FLG mutations were associated with asthma in children with atopic dermatitis or allergic sensitization only. Stratifying for sex, the risk of asthma was only increased in boys with lower lung function; aOR (95% CI) 7.7 (2.5, 23.6), and in girls with FLG mutations; aOR (95% CI) 3.5 (1.5, 8.2). Lower lung function and impaired skin barrier function in infancy may increase the risk of asthma at age 3 years.

Revitalizing the skin: Exploring the role of barrier repair moisturizers.

Moisturizers are designed to maintain skin health and treat dermatological conditions associated with impaired skin barrier function. However, differences in their composition account for the differences in their effect. This narrative review aims to discuss the role of barrier repair moisturizers, highlight the role of different components in a moisturizer and their role in impaired skin conditions (e.g., dry, itchy, inflamed, sensitive skin, atopic eczema), and thereby empower dermatologists and pediatricians in selecting the right moisturizer. PubMed, Embase, and Scopus electronic databases were searched from January 2000 to June 2023 for publications on skin barrier repair and use of barrier repair moisturizers for the treatment of dry, itchy, inflamed, sensitive skin, or atopic eczema. Studies conducted in humans, published in English for which full texts were freely available were included. The structure and composition of lipid lamellae within the stratum corneum play an important role in maintaining an effective skin barrier and protecting the body from various external assaults. Endocannabinoid mediators play an active role in maintaining skin barrier function. Moisturizers containing physiological lipids and functional ingredients (e.g., endocannabinoids such as palmitoylethanolamide [PEA]) and based on the principles of biomimic technology are demonstrated to be beneficial for the management of conditions associated with a disrupted skin barrier. Moisturizer based on the innovative biomimic formulation has good cosmetic efficacy and is generally well tolerated, and the addition of PEA might represent a new generation of compounds that may be beneficial for long-term management of impaired skin conditions.

Evaluating the Irritant Factors of Silicone and Hydrocolloid Skin Contact Adhesives Using Trans-Epidermal Water Loss, Protein Stripping, Erythema, and Ease of Removal.

A composite silicone skin adhesive material was designed to improve its water vapor permeability to offer advantages to wearer comfort compared to existing skin adhesive dressings available (including perforated silicone and hydrocolloid products). The chemical and mechanical properties of this novel dressing were analyzed to show that it has a high creep compliance, offering anisotropic elasticity that is likely to place less stress on the skin. A participant study was carried out in which 31 participants wore a novel silicone skin adhesive (Sil2) and a hydrocolloid competitor and were monitored for physiological response to the dressings. Trans-epidermal water loss (TEWL) was measured pre- and postwear to determine impairment of skin barrier function. Sil2 exhibited a higher vapor permeability than the hydrocolloid dressings during wear. Peel strength measurements and dye counter staining of the removed dressings showed that the hydrocolloid had a higher adhesion to the participants' skin, resulting in a greater removal of proteins from the stratum corneum and a higher pain rating from participants on removal. Once the dressings were removed, TEWL of the participants skin beneath the Sil2 was close to normal in comparison to the hydrocolloid dressings that showed an increase in skin TEWL, indicating that the skin had been highly occluded. Analysis of the skin immediately after removal showed a higher incidence of erythema following application of hydrocolloid dressings (>60%) compared to Sil2, (<30%). In summary, this modified silicone formulation demonstrates superior skin protection properties compared to hydrocolloid dressings and is more suitable for use as a skin adhesive.

The Skin and Inflamm-Aging.

With its unique anatomical location facing both the external and internal environment, the skin has crucial functions, including shielding the body from damage caused by ultraviolet radiation and chemicals, preventing water loss, acting as a primary barrier against pathogens, participating in metabolic processes like vitamin D production and temperature control and relaying information to the body through sensory and proprioceptor nerves. Like all organ systems, skin is known to undergo multiple changes with aging. A better understanding of the mechanisms that mediate aging-related skin dysfunction may allow the creation of targeted therapeutics that have beneficial effects not only on aged skin but also on other organs and tissues that experience a loss of or decline in function with aging. The skin is the largest organ of the body and can contribute to serum inflammatory mediator levels. One alteration known to occur with age is an impairment of skin barrier function; since disruption of the barrier is known to induce inflammation, skin may be a major contributor to the sustained, sub-clinical systemic inflammation associated with aging. Such "inflamm-aging" may underlie many of the deleterious changes observed in aged individuals. This review explores the role of age-related skin changes, skin inflammation and inflamm-aging.

Toll-like receptors: their roles in pathomechanisms of atopic dermatitis.

The skin functions as a physical barrier and represents the first line of the innate immune system. There is increasing evidence that toll-like receptors (TLRs) are involved in the pathomechanisms of not only infectious diseases, but also non-infectious inflammatory diseases. Interestingly, it has been demonstrated that TLRs recognize both exogenous threats, e.g. bacteria and viruses, and endogenous danger signals related to inflammation, cell necrosis, or tissue damage. Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease, which is associated with impaired skin barrier function, increased skin irritability to non-specific stimuli, and percutaneous sensitization. The impairment of skin barrier function in AD allows various stimuli, such as potential allergens and pathogens, to penetrate the skin and activate the innate immune system, including TLR signaling, which can lead to the development of adaptive immune reactions. In this review, I summarize the current understanding of the roles of TLR signaling in the pathogenesis of AD, with special emphasis on skin barrier function and inflammation.

Targeting dysbiosis in psoriasis, atopic dermatitis, and hidradenitis suppurativa: the gut-skin axis and microbiome-directed therapy

Emerging evidence highlights the gut-skin microbiota as a potential therapeutic target for the management of inflammatory-driven cutaneous diseases as well as the interconnection of the gut-skin microbiota in disease pathogenesis and progression. Although not fully understood, recent research has indicated that commensal microbiota and the interaction of the gut-skin axis play an important role in maintaining skin homeostasis. Dysbiosis and disruption of the skin-gut microbiome may lead to impaired skin barrier function, thus triggering downstream inflammatory responses involved in the development of inflammatory skin disorders, especially in atopic dermatitis, psoriasis, and hidradenitis suppurativa. The skin microbiome may also serve as adjunctive therapeutic modalities for treatment. Herein, we review the latest reports on the interrelationship between microbial dysbiosis and inflammatory cutaneous diseases as well as emerging microbiome-directed therapeutics in atopic dermatitis, psoriasis, and hidradenitis suppurativa.

The status and prospects of studies about atopic dermatitis

Atopic dermatitis (AD) is a chronic, relapsing, pruritic inflammatory disease with a high prevalence, ranking as the leading non-fatal burden of skin diseases. The pathogenesis of AD involves interactions among genetic factors, impaired skin barrier function, dysbiosis, and immune dysregulation. The immune phenotype is highly heterogeneous, with the Th2-dominant immune response. AD exhibits diverse clinical phenotypes, posing challenges for the establishment of clinical diagnostic criteria and personalized management. Targeted biologic therapies focusing on Th2-type inflammatory responses and small-molecule drugs blocking inflammatory signaling pathways have significantly improved the management of the moderate or severe AD. However, the balance between efficacy and safety remains to be evaluated due to limited data. Despite significant advancement in basic and clinical research on AD in recent years, there are still many questions that need to be resolved urgently.

Evaluation of skin barrier function based on skin dermoscopic features in patients with rosacea.

Evaluation of skin barrier function based on skin dermoscopic features in patients with rosacea.

Development of Spray Dried Spirulina Protein-Berry Pomace Polyphenol Particles to Attenuate Pollution-Induced Skin Damage: A Convergent Food-Beauty Approach.

Spray drying (SD) microencapsulation of phytochemicals from berry pomaces with Spirulina protein (SP) was incorporated into a cosmeceutical topical formulation to mitigate pollution skin damage. Initially, microparticles produced with SP and polyphenols recovered from fruit pomaces (elderberry SP-EB and muscadine grape SP-MG) were characterized regarding physicochemical and phytochemical content (polyphenol load, carotenoid and phycocyanin contents and antioxidant activity). SP had low total phenolic content (7.43 ± 0.23 mg GAE/g DW), but complexation with elderberry or muscadine grape pomaces polyphenols led to a substantial increase (27.63 ± 1.15 SP-EB and 111.0 ± 2.6 mg GAE/g DW SP-MG). SP-MG particles had higher anthocyanin (26.87 ± 1.25 mg/g) and proanthocyanidin (9.02 ± 0.74 mg/g) contents compared to SP-EB particles. SP-MG were prioritized to prepare a topical gel to attenuate skin oxinflammatory markers and prevent skin barrier disruption using ex vivo human biopsies exposed to diesel engine exhaust (DEE). The immunofluorescence results showed increased oxidative protein damage and inflammation associated with impaired skin barrier function after DEE exposure while topical application of gel formulated with SP-MG mitigated these effects. Overall, this study demonstrated that protein-polyphenol complexation is a synergistic strategy to stabilize and deliver residual fruit/algae phytoactives into cosmeceutical products for skin health applications.

Nanocellulose-Based Film-Forming Hydrogels for Improved Outcomes in Atopic Skin.

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by impaired skin barrier function. Amongst the various dermal formulations that are being used and/or investigated for AD treatment, one of the advanced approaches is the use of hydrogels as film-forming systems that are applied directly to the skin and have the added value of providing a physical barrier, which is lacking in atopic skin. Novel film-forming hydrogels based on two different nanocrystalline celluloses (NCCs) in combination with one of two natural polymers (alginate or pectin) were developed for incorporation of betamethasone dipropionate (BDP). Initially, the low water solubility of BDP was resolved by prior dissolution in a self-microemulsifying drug delivery system (SMEDDS). The mixture of Kolliphor® EL/Capryol® 90 in a ratio of 8/2 was chosen on the merit of its high BDP-saturated solubility and no BDP precipitation upon water dilution, enabling BDP to remain dissolved after incorporation into hydrogels. The solvent evaporation method was used to prepare the films, and their high water retention capacity was confirmed in vitro on artificial membranes and pig ear skin. The presented results thus confirm NCC-based film-forming hydrogels as a very promising drug delivery system for AD treatment.

Proteinase K/Retinoic Acid-Loaded Cationic Liposomes as Multifunctional Anti-Acne Therapy to Disorganize Biofilm and Regulate Keratinocyte Proliferation.

Simultaneous anti-Cutibacterium acnes and anti-inflammatory actions are highly beneficial in treating acne vulgaris. In this study, we present novel anti-acne nanovesicles based on liposomes loaded with proteinase K (PK), retinoic acid (RA), and soyaethyl morpholinium ethosulfate (SME) to achieve an effective and safe treatment. This study examined in vitro planktonic and biofilm C. acnes elimination, as well as the keratinocyte proliferation suppression by liposomes. The multifunctional liposomes for treating C. acnes in mice were also evaluated. We acquired multifunctional liposomes with a size of 71 nm and zeta potential of 31 mV. The antimicrobial activity of SME was enhanced after liposomal encapsulation according to the reduction of minimum bactericidal concentration (MBC) by 6-fold. The multifunctional liposomes exhibited a synergistically inhibitory effect on biofilm C. acnes colonization compared with the liposomes containing PK or those containing SME individually. The adhesive bacterial colony in the microplate was lessened by 62% after multifunctional liposome intervention. All liposomal formulations tested here demonstrated no cytotoxicity against the normal keratinocytes but inhibited C. acnes-stimulated cell hyperproliferation. The in vitro scratch assay indicated that the liposomal RA-but not free RA-restrained keratinocyte migration. The animal study showed that free RA combined with SME and multifunctional nanovesicles had a similar effect on diminishing C. acnes colonies in the skin. On the other hand, liposomes exhibited superior performance in recovering the impaired skin barrier function than the free control. We also found that RA-loaded nanovesicles had greater skin tolerability than free RA. The cationic liposomes containing dual PK and RA represented a potential treatment to arrest bacterial infection and associated inflammation in acne.

Effect of sphingosine and phytosphingosine ceramide ratio on lipid arrangement and barrier function in skin lipid models

The lipids in the uppermost layer of the skin, the stratum corneum (SC), play an important role in the skin barrier function. The three main subclasses in the SC lipid matrix are ceramides (CER), cholesterol, and free fatty acids. In inflammatory skin diseases, such as atopic dermatitis and psoriasis, the SC lipid composition is modulated compared to the composition in healthy SC. One of the main alterations is the molar ratio between the concentration of CER N-(tetracosanoyl)-sphingosine (CER NS) and CER N-(tetracosanoyl)-phytosphingosine (CER NP), which correlated with an impaired skin barrier function. In the present study, we investigated the impact of varying the CER NS:CER NP ratios on the lipid organization, lipid arrangement, and barrier functionality in SC lipid model systems. The results indicate that a higher CER NS:CER NP ratio as observed in diseased skin did not alter the lipid organization or lipid arrangement in the long periodicity phase encountered in SC. The trans-epidermal water loss, an indication of the barrier functionality, was significantly higher for the CER NS:CER NP 2:1 model (mimicking the ratio in inflammatory skin diseases) compared to the CER NS:CER NP 1:2 ratio (in healthy skin). These findings provide a more detailed insight into the lipid organization in both healthy and diseased skin and suggest that in vivo the molar ratio between CER NS:CER NP contributes to barrier impairment as well but might not be the main factor.