Lipid-based microemulsion gel for the topical delivery of methotrexate: an optimized, rheologically acceptable formulation with conducive dermatokinetics.

In the present study, we have formulated a methotrexate (MTX)-loaded microemulsion topical gel employing quality-by-design optimization. The optimized lipid-based microemulsion was incorporated into a 2% carbopol gel. The prepared formulation was characterized for micromeritics, surface charge, surface morphology, conductivity studies, rheology studies, texture analysis/spreadability, drug entrapment, and drug loading studies. The formulation was further evaluated for drug release and release kinetics, cytotoxicity assays, drug permeation and drug retention studies, and dermatokinetics. The developed nanosystem was not only rheologically acceptable but also offered substantial drug entrapment and loading. From drug release studies, it was observed that the nanogel showed higher drug release at pH 5.0 compared to plain MTX, plain gel, and plain microemulsion. The developed system with improved dermatokinetics, nanometric size, higher drug loading, and enhanced efficacy towards A314 squamous epithelial cells offers a huge promise in the topical delivery of methotrexate.

A miRNA-based epigenetic molecular clock for biological skin-age prediction.

Skin aging is one of the visible characteristics of the aging process in humans. In recent years, different biological clocks have been generated based on protein or epigenetic markers, but few have focused on biological age in the skin. Arrest the aging process or even being able to restore an organism from an older to a younger stage is one of the main challenges in the last 20 years in biomedical research. We have implemented several machine learning models, including regression and classification algorithms, in order to create an epigenetic molecular clock based on miRNA expression profiles of healthy subjects to predict biological age-related to skin. Our best models are capable of classifying skin samples according to age groups (18-28; 29-39; 40-50; 51-60 or 61-83 years old) with an accuracy of 80% or predict age with a mean absolute error of 10.89 years using the expression levels of 1856 unique miRNAs. Our results suggest that this kind of epigenetic clocks arises as a promising tool with several applications in the pharmaco-cosmetic industry.

Reactive oxygen species-responsive supramolecular deucravacitinib self-assembly polymer micelles alleviate psoriatic skin inflammation by reducing mitochondrial oxidative stress.

Introduction: The new topical formula is urgent needed to meet clinical needs for majority mild patients with psoriasis. Deucravacitinib exerts outstanding anti-psoriatic capacity as an oral TYK2 inhibitor; however, single therapy is insufficient to target the complicated psoriatic skin, including excessive reactive oxygen species (ROS) and persistent inflammation. To address this need, engineered smart nano-therapeutics hold potential for the topical delivery of deucravacitinib. Methods: hydrophobic Deucravacitinib was loaded into polyethylene glycol block-polypropylene sulphide (PEG-b-PPS) for transdermal delivery in the treatment of psoriasis. The oxidative stress model of HaCaT psoriasis was established by TNF-α and IL-17A in vitro. JC-1 assay, DCFH-DA staining and mtDNA copy number were utilized to assess mitochondrial function. 0.75% Carbopol®934 was incorporated into SPMs to produce hydrogels and Rhb was labeled to monitor penetration by Immunofluorescence. In vivo, we established IMQ-induced psoriatic model to evaluate therapeutic effect of Car@Deu@PEPS. Results: Deu@PEPS exerted anti-psoriatic effects by restoring mitochondrial DNA copy number and mitochondrial membrane potential in HaCaT. In vivo, Car@Deu@PEPS supramolecular micelle hydrogels had longer retention time in the dermis in the IMQ-induced ROS microenvironment. Topical application of Car@Deu@PEPS significantly restored the normal epidermal architecture of psoriatic skin with abrogation of splenomegaly in the IMQ-induced psoriatic dermatitis model. Car@Deu@PEPS inhibited STAT3 signaling cascade with a corresponding decrease in the levels of the differentiation and proliferative markers Keratin 17 and Cyclin D1, respectively. Meanwhile, Car@Deu@PEPS alleviated IMQ-induced ROS generation and subsequent NLRP3 inflammasome-mediated pyroptosis. Conclusion: Deu@PEPS exerts prominent anti-inflammatory and anti-oxidative effects, which may offers a more patient-acceptable therapy with fewer adverse effects compared with oral deucravacitinib.

MRGPRX2 antagonist GE1111 attenuated DNFB-induced atopic dermatitis in mice by reducing inflammatory cytokines and restoring skin integrity.

Introduction: Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterised by itching, erythema, and epidermal barrier dysfunction. The pathogenesis of AD is complex and multifactorial; however,mast cell (MC) activation has been reported to be one of the crucial mechanisms in the pathogenesis of AD. The MC receptor Mas related G protein-coupled receptor-X2 (MRGPRX2) has been identified as a prominent alternative receptor to the IgE receptor in causing MC activation and the subsequent release of inflammatory mediators. The current study aimed to evaluate the therapeutic effect of a novel small molecule MRGPRX2 antagonist GE1111 in AD using in vitro and in vivo approaches. Methods: We developed an in vitro cell culture disease model by using LAD-2 MC, HaCaT keratinocytes and RAW 264.7 macrophage cell lines. We challenged keratinocytes and macrophage cells with CST-14 treated MC supernatant in the presence and absence of GE1111 and measured the expression of tight junction protein claudin 1, inflammatory cytokines and macrophage phagocytosis activity through immunohistochemistry, western blotting, RT-qPCR and fluorescence imaging techniques. In addition to this, we developed a DFNB-induced AD model in mice and evaluated the protective effect and underlying mechanism of GE1111. Results and Discussion: Our in vitro findings demonstrated a potential therapeutic effect of GE1111, which inhibits the expression of TSLP, IL-13, MCP-1, TNF-a, and IL-1ß in MC and keratinocytes. In addition to this, GE1111 was able to preserve the expression of claudin 1 in keratinocytes and the phagocytotic activity of macrophage cells. The in vivo results demonstrated that GE1111 treatment significantly reduced phenotypic changes associated with AD (skin thickening, scaling, erythema and epidermal thickness). Furthermore, immunohistochemical analysis demonstrated that GE1111 treatment preserved the expression of the tight junction protein Involucrin and reduced the expression of the inflammatory mediator periostin in the mouse model of AD. These findings were supported by gene and protein expression analysis, where GE1111 treatment reduced the expression of TSLP, IL-13, and IL-1ß, as well as downstream signalling pathways of MRGPRX2 in AD skin lesions. In conclusion, our findings provide compelling in vitro and in vivo evidence supporting the contribution of MRGPRX2-MC interaction with keratinocytes and macrophages in the pathogenesis of AD.

Screening mitochondria-related biomarkers in skin and plasma of atopic dermatitis patients by bioinformatics analysis and machine learning.

Background: There is a significant imbalance of mitochondrial activity and oxidative stress (OS) status in patients with atopic dermatitis (AD). This study aims to screen skin and peripheral mitochondria-related biomarkers, providing insights into the underlying mechanisms of mitochondrial dysfunction in AD. Methods: Public data were obtained from MitoCarta 3.0 and GEO database. We screened mitochondria-related differentially expressed genes (MitoDEGs) using R language and then performed GO and KEGG pathway analysis on MitoDEGs. PPI and machine learning algorithms were also used to select hub MitoDEGs. Meanwhile, the expression of hub MitoDEGs in clinical samples were verified. Using ROC curve analysis, the diagnostic performance of risk model constructed from these hub MitoDEGs was evaluated in the training and validation sets. Further computer-aided algorithm analyses included gene set enrichment analysis (GSEA), immune infiltration and mitochondrial metabolism, centered on these hub MitoDEGs. We also used real-time PCR and Spearman method to evaluate the relationship between plasma circulating cell-free mitochondrial DNA (ccf-mtDNA) levels and disease severity in AD patients. Results: MitoDEGs in AD were significantly enriched in pathways involved in mitochondrial respiration, mitochondrial metabolism, and mitochondrial membrane transport. Four hub genes (BAX, IDH3A, MRPS6, and GPT2) were selected to take part in the creation of a novel mitochondrial-based risk model for AD prediction. The risk score demonstrated excellent diagnostic performance in both the training cohort (AUC = 1.000) and the validation cohort (AUC = 0.810). Four hub MitoDEGs were also clearly associated with the innate immune cells' infiltration and the molecular modifications of mitochondrial hypermetabolism in AD. We further discovered that AD patients had considerably greater plasma ccf-mtDNA levels than controls (U = 92.0, p< 0.001). Besides, there was a significant relationship between the up-regulation of plasma mtDNA and the severity of AD symptoms. Conclusions: The study highlights BAX, IDH3A, MRPS6 and GPT2 as crucial MitoDEGs and demonstrates their efficiency in identifying AD. Moderate to severe AD is associated with increased markers of mitochondrial damage and cellular stress (ccf=mtDNA). Our study provides data support for the variation in mitochondria-related functional characteristics of AD patients.

Influence of Surfactant on the Skin Permeation of Methylisothiazolinone and Methylchloroisothiazolinone.

Patch tests are often used in safety evaluations to identify the substance causing skin irritation, but the same substance can sometimes give positive or negative results depending on the test conditions. Here, we investigated differences in the skin penetration of two test compounds under different application conditions. We studied the effects of the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant polysorbate 80 (PS) on skin penetration of the preservatives methylisothiazolinone (MT) and methylchloroisothiazolinone (MCT), which are used in cosmetics such as shampoos. The skin permeation of MT was enhanced by SDS but was unchanged by PS. Skin impedance decreased in the presence of SDS whereas PS had the same effect as the control aqueous solution, suggesting that SDS reduction of the barrier function of skin affects the permeation of MT, a hydrophilic drug. Application of a mixture of MCT and MT in the presence of SDS did not affect the skin permeation of MCT whereas the permeation of MT was enhanced by SDS, indicating that the skin permeation of MCT is less affected by SDS than is MT. Thus, attention should be paid to the possible effect of co-solutes, especially hydrophilic drugs.

Ultraviolet Protection From a Patented Amino Acid Complex Technology.

OBJECTIVE:   This study aimed to investigate the ultraviolet (UV) protection/repair benefits of a patented Amino Acid Complex (AAComplex). METHODS: I) AAComplex was incubated with dermal fibroblasts, with/without UVA, and collagen I was measured with a GlasBoxPlus device. II) A lotion, with/without AAComplex (1%) was applied topically to skin explants, following UVA irradiation, and quantified for health-related biomarkers (TNFalpha, histamine, and MMP-1). III) A broad spectrum sunscreen with SPF 46 and a skincare serum containing AAComplex (2%) were assessed using epidermal equivalents, in the presence of UV irradiation, for effects on IL-1alpha, thymine dimers, Ki-67, filaggrin and Nrf2. RESULTS: I) Collagen I synthesis in dermal fibroblasts was significantly decreased after UVA compared to without UV. The presence of AAComplex prevented this decrease. II) UVA irradiation of skin explants increased histamine, TNFα, and MMP-1. Hydrocortisone aceponate cream significantly decreases all 3 biomarkers. AAComplex contained lotion also significantly decreased all 3 biomarkers, the no AAComplex control lotion only reduced histamine. III) With the regimen of sunscreen + AAComplex contained skincare serum, the significant reduction in IL-1alpha was observed along with a complete recovery of Ki-67 and stimulation of filaggrin and Nrf2T. No thymine dimer positive cell was observed indicating the most positive skin impact from the regiment.  Conclusion: This research using different human skin models demonstrated that AAComplex can provide protection and damage repair caused by UV, at the ingredient level also when formulated in a serum or lotion formula. Skin may be best protected from UV damage when the regimen is used.   J Drugs Dermatol. 2024;23(5):366-375. doi:10.36849/JDD.7916.

Key Transdermal Patch Using Cannabidiol-Loaded Nanocarriers with Better Pharmacokinetics in vivo.

Purpose: Cannabidiol (CBD) is a promising therapeutic drug with low addictive potential and a favorable safety profile. However, CBD did face certain challenges, including poor solubility in water and low oral bioavailability. To harness the potential of CBD by combining it with a transdermal drug delivery system (TDDS). This innovative approach sought to develop a transdermal patch dosage form with micellar vesicular nanocarriers to enhance the bioavailability of CBD, leading to improved therapeutic outcomes. Methods: A skin-penetrating micellar vesicular nanocarriers, prepared using nano emulsion method, cannabidiol loaded transdermal nanocarriers-12 (CTD-12) was presented with a small particle size, high encapsulation efficiency, and a drug-loaded ratio for CBD. The skin permeation ability used Strat-M™ membrane with a transdermal diffusion system to evaluate the CTD and patch of CTD-12 (PCTD-12) within 24 hrs. PCTD-12 was used in a preliminary pharmacokinetic study in rats to demonstrate the potential of the developed transdermal nanocarrier drug patch for future applications. Results: In the transdermal application of CTD-12, the relative bioavailability of the formulation was 3.68 ± 0.17-fold greater than in the free CBD application. Moreover, PCTD-12 indicated 2.46 ± 0.18-fold higher relative bioavailability comparing with free CBD patch in the ex vivo evaluation. Most importantly, in the pharmacokinetics of PCTD-12, the relative bioavailability of PCTD-12 was 9.47 ± 0.88-fold higher than in the oral application. Conclusion: CTD-12, a transdermal nanocarrier, represents a promising approach for CBD delivery, suggesting its potential as an effective transdermal dosage form.

The Effect of α-Arbutin on UVB-Induced Damage and Its Underlying Mechanism.

Ultraviolet radiation can heighten tyrosinase activity, stimulate melanocyte production, impede the metabolism of numerous melanocytes, and result in the accumulation of plaques on the skin surface. α-Arbutin, a bioactive substance extracted from the arbutin plant, has been widely used for skin whitening. In this study, the whitening effect of α-arbutin by inhibiting tyrosinase activity and alleviating the photoaging effect induced by UVB are investigated. The results indicate that α-arbutin can inhibit skin inflammation, and its effectiveness is positively correlated with concentration. Moreover, α-arbutin can reduce the skin epidermal thickness, decrease the number of inflammatory cells, and down-regulate the expression levels of IL-1ß, IL-6 and TNF-α, which are inflammatory factors. It also promotes the expression of COL-1 collagen, thus playing an important role in anti-inflammatory action. Network pharmacology, metabolomics and transcriptomics further confirm that α-arbutin is related to the L-tyrosine metabolic pathway and may interfere with various signaling pathways related to melanin and other photoaging by regulating metabolic changes. Therefore, α-arbutin has a potential inhibitory effect on UVB-induced photoaging and possesses a whitening effect as a cosmetic compound.

Study on the Skincare Effects of Red Rice Fermented by Aspergillus oryzae In Vitro.

Red rice, a variety of pigmented grain, serves dual purposes as both a food and medicinal resource. In recent years, we have witnessed an increasing interest in the dermatological benefits of fermented rice extracts, particularly their whitening and hydrating effects. However, data on the skincare advantages derived from fermenting red rice with Aspergillus oryzae remain sparse. This study utilized red rice as a substrate for fermentation by Aspergillus oryzae, producing a substance known as red rice Aspergillus oryzae fermentation (RRFA). We conducted a preliminary analysis of RRFA's composition followed by an evaluation of its skincare potential through various in vitro tests. Our objective was to develop a safe and highly effective skincare component for potential cosmetic applications. RRFA's constituents were assessed using high-performance liquid chromatography (HPLC), Kjeldahl nitrogen determination, the phenol-sulfuric acid method, and enzyme-linked immunosorbent assay (ELISA). We employed human dermal fibroblasts (FB) to assess RRFA's anti-aging and antioxidative properties, immortalized keratinocytes (HaCaT cells) and 3D epidermal models to examine its moisturizing and reparative capabilities, and human primary melanocytes (MCs) to study its effects on skin lightening. Our findings revealed that RRFA encompasses several bioactive compounds beneficial for skin health. RRFA can significantly promote the proliferation of FB cells. And it markedly enhances the mRNA expression of ECM-related anti-aging genes and reduces reactive oxygen species production. Furthermore, RRFA significantly boosts the expression of Aquaporin 3 (AQP3), Filaggrin (FLG), and Hyaluronan Synthase 1 (HAS1) mRNA, alongside elevating moisture levels in a 3D epidermal model. Increases were also observed in the mRNA expression of Claudin 1 (CLDN1), Involucrin (IVL), and Zonula Occludens-1 (ZO-1) in keratinocytes. Additionally, RRFA demonstrated an inhibitory effect on melanin synthesis. Collectively, RRFA contains diverse ingredients which are beneficial for skin health and showcases multifaceted skincare effects in terms of anti-aging, antioxidant, moisturizing, repairing, and whitening capabilities in vitro, highlighting its potential for future cosmetic applications.

Differential Anti-Fibrotic and Remodeling Responses of Human Dermal Fibroblasts to Artemisia sp., Artemisinin, and Its Derivatives.

Fibrosis is a ubiquitous pathology, and prior studies have indicated that various artemisinin (ART) derivatives (including artesunate (AS), artemether (AM), and dihydroartemisinin (DHA)) can reduce fibrosis in vitro and in vivo. The medicinal plant Artemisia annua L. is the natural source of ART and is widely used, especially in underdeveloped countries, to treat a variety of diseases including malaria. A. afra contains no ART but is also antimalarial. Using human dermal fibroblasts (CRL-2097), we compared the effects of A. annua and A. afra tea infusions, ART, AS, AM, DHA, and a liver metabolite of ART, deoxyART (dART), on fibroblast viability and expression of key fibrotic marker genes after 1 and 4 days of treatment. AS, DHA, and Artemisia teas reduced fibroblast viability 4 d post-treatment in up to 80% of their respective controls. After 4 d of treatment, AS DHA and Artemisia teas downregulated ACTA2 up to 10 fold while ART had no significant effect, and AM increased viability by 10%. MMP1 and MMP3 were upregulated by AS, 17.5 and 32.6 fold, respectively, and by DHA, 8 and 51.8 fold, respectively. ART had no effect, but A. annua and A. afra teas increased MMP3 5 and 16-fold, respectively. Although A. afra tea increased COL3A1 5 fold, MMP1 decreased >7 fold with no change in either transcript by A. annua tea. Although A. annua contains ART, it had a significantly greater anti-fibrotic effect than ART alone but was less effective than A. afra. Immunofluorescent staining for smooth-muscle α-actin (α-SMA) correlated well with the transcriptional responses of drug-treated fibroblasts. Together, proliferation, qPCR, and immunofluorescence results show that treatment with ART, AS, DHA, and the two Artemisia teas yield differing responses, including those related to fibrosis, in human dermal fibroblasts, with evidence also of remodeling of fibrotic ECM.

Comparative study of melasma in patients before and after treatment based on lipomics.

BACKGROUND: Skin barrier alterations play a crucial function in melasma development. Past researches have demonstrated variations in lipid content between the epidermis of melasma lesions and normal tissues, along with the varied expression of lipid-related genes in melasma. This study aimed to analyze the lipidome profiles of skin surface lipids (SSL) in patients with melasma before and after treatment to understand associated abnormalities. METHODS: Melasma was treated with tranexamic acid orally and hydroquinone cream topically. Disease was assessed using the Melasma Area and Severity Index (MASI), and the impact to life was evaluated with Melasma Quality of Life (MELASQoL) score. Epidermal melanin particles were observed using reflection confocal microscopy (RCM), whereas epidermal pigment and blood vessel morphology were observed using dermoscopy, and SSL samples were collected. Specific information regarding alterations in lipid composition was obtained through multivariate analysis of the liquid chromatography-mass spectrometry data. RESULTS: After treatment, patients with melasma exhibited decreased MASI and MELASQoL scores (P < 0.001); RCM revealed reduced melanin content in the lesions, and dermoscopy revealed fewer blood vessels. Fifteen lipid subclasses and 382 lipid molecules were identified using lipidomic assays. The expression levels of total lipids, phosphatidylcholine, and phosphatidylethanolamine in the melasma lesions decreased after treatment (P < 0.05). CONCLUSION: This study revealed alterations in the SSL composition after effective melasma treatment, suggesting a compensatory role for lipids in melasma barrier function. The mechanism involving SSL and the lipid barrier, which influences melasma's occurrence, needs further elucidation.

Plexin B2 tissue expression and related gene polymorphisms in psoriasis and their relation to NB-UVB and Acitretin therapy.

Psoriasis is a chronic, immune-mediated, hyperproliferative skin disease. Etiopathogenesis of psoriasis is not well understood. Plexin B2 was found to have effects on CD100-mediated T-cell morphology and expressed in the immune system. It may play a role in the pathogenesis of psoriasis. To assess the tissue level of plexin-B2 and plexin B2 related gene polymorphism which is signal regulatory protein gamma (SIRPγ-rs71212732) in psoriatic patients before and after NB-UVB, acitretin therapy alone or in combination and to detect correlation between level of tissue plexin B2 and disease severity and improvement. This single blinded randomized controlled trial was carried on 50 psoriatic patients and 50 healthy controls. Psoriasis Area and Severity Index score (PASI) was used to evaluate the disease severity. Tissue plexin-b2 level was measured using ELISA and SIRPγ-rs71212732 (T\C) was assessed using TaqMan™ assays and real-time PCR. A significant lower tissue plexin-B2 level was observed in control group (2.9 ± 0.6 pg/g) than cases (25.8 ± 2.8, pg/g) (p < 0.001). Also, a significantly higher tissue plexin-B2 level was observed in sever psoriasis (32.7 ± 3.8 pg/ml) in than moderate psoriasis (13.6 ± 2.1 pg/ml, p = 0.001). Tissue plexin B2 was positively correlated with diseases severity. Significantly higher (TC& TT) genotypes and mutant (C) allele among patients compared to the controls, p < 0.001 for all. Tissue plexin-b2 level was high in psoriasis vulgaris with positive correlation with disease severity and decreased after treatment. This may indicate a role of plexin-b2 in psoriasis vulgaris pathogenesis.

Nanosuspension-Loaded Dissolving Microneedle Patches for Enhanced Transdermal Delivery of a Highly Lipophilic Cannabidiol.

Purpose: Transdermal Drug Delivery System (TDDS) offers a promising alternative for delivering poorly soluble drugs, challenged by the stratum corneum's barrier effect, which restricts the pool of drug candidates suitable for TDDS. This study aims to establish a delivery platform specifically for highly lipophilic drugs requiring high doses (log P > 5, dose > 10 mg/kg/d), to improve their intradermal delivery and enhance solubility. Methods: Cannabidiol (CBD, log P = 5.91) served as the model drug. A CBD nanosuspension (CBD-NS) was prepared using a bottom-up method. The particle size, polydispersity index (PDI), zeta potential, and concentration of the CBD-NS were characterized. Subsequently, CBD-NS was incorporated into dissolving microneedles (DMNs) through a one-step manufacturing process. The intradermal dissolution abilities, physicochemical properties, mechanical strength, insertion depth, and release behavior of the DMNs were evaluated. Sprague-Dawley (SD) rats were utilized to assess the efficacy of the DMN patch in treating knee synovitis and to analyze its skin permeation kinetics and pharmacokinetic performance. Results: The CBD-NS, stabilized with Tween 80, exhibited a particle size of 166.83 ± 3.33 nm, a PDI of 0.21 ± 0.07, and a concentration of 46.11 ± 0.52 mg/mL. The DMN loaded with CBD-NS demonstrated favorable intradermal dissolution and mechanical properties. It effectively increased the delivery of CBD into the skin, extended the action's duration in vivo, and enhanced bioavailability. CBD-NS DMN exhibited superior therapeutic efficacy and safety in a rat model of knee synovitis, significantly inhibiting TNF-α and IL-1ß compared with the methotrexate subcutaneous injection method. Conclusion: NS technology effectively enhances the solubility of the poorly soluble drug CBD, while DMN facilitates penetration, extends the duration of action in vivo, and improves bioavailability. Furthermore, CBD has shown promising therapeutic outcomes in treating knee synovitis. This innovative drug delivery system is expected to offer a more efficient solution for the administration of highly lipophilic drugs akin to CBD, thereby facilitating high-dose administration.

Incorporation of Finasteride-Loaded Microspheres into Personalized Microneedle for Sustained Transdermal Delivery.

Although finasteride (FNS) tablets are considered the most effective drug for the treatment of androgenetic alopecia (AGA), their clinical applications are limited due to the associated side effects including decreased libido, breast enlargement, and liver dysfunction. In this study, we have developed a personalized microneedle (PMN) with a double-layer structure that incorporates FNS-loaded microspheres (MPs) to accommodate irregular skin surfaces. This design enables the sustained release of FNS, thereby reducing potential side effects. The needle body was synthesized with high-strength hyaluronic acid (HA) as the base material substrate. The backing layer utilized methacrylate gelatin (GelMA) with specific toughness, enabling PMN to penetrate the skin while adapting to various skin environments. The length of PMN needles (10 × 10) was approximately 600 µm, with the bottom of the needles measuring about 330 µm × 330 µm. The distance between adjacent tips was around 600 µm, allowing the drug to penetrate the stratum corneum of the skin. The results of the drug release investigation indicated the sustained and regulated release of FNS from PMN, as compared to that of pure FNS and FNS-MPs. Further, the cytotoxicity assay demonstrates that PMS displays good cytocompatibility. Altogether, this mode of administration has immense potential for the development of delivery of other drugs, as well as in the medical field.

Research progress on the role of macrophages in acne and regulation by natural plant products.

Acne vulgaris is one of the most common skin diseases. The current understanding of acne primarily revolves around inflammatory responses, sebum metabolism disorders, aberrant hormone and receptor expression, colonization by Cutibacterium acnes, and abnormal keratinization of follicular sebaceous glands. Although the precise mechanism of action remains incompletely understood, it is plausible that macrophages exert an influence on these pathological features. Macrophages, as a constituent of the human innate immune system, typically manifest distinct phenotypes across various diseases. It has been observed that the polarization of macrophages toward the M1 phenotype plays a pivotal role in the pathogenesis of acne. In recent years, extensive research on acne has revealed an increasing number of natural remedies exhibiting therapeutic efficacy through the modulation of macrophage polarization. This review investigates the role of cutaneous macrophages, elucidates their potential significance in the pathogenesis of acne, a prevalent chronic inflammatory skin disorder, and explores the therapeutic mechanisms of natural plant products targeting macrophages. Despite these insights, the precise role of macrophages in the pathogenesis of acne remains poorly elucidated. Subsequent investigations in this domain will further illuminate the pathogenesis of acne and potentially offer guidance for identifying novel therapeutic targets for this condition.

Cutaneous inflammasome driving ASC / gasdermin-D activation and IL-1ß-secreting macrophages in severe atopic dermatitis.

Atopic dermatitis (AD) is an inflammatory skin disease with intense pruritus, and chronic skin colonization by Staphylococcus aureus. To understand the inflammatory status in AD, we investigated the inflammasome complex, that activates ASC (Apoptosis-associated speck-like protein containing a CARD), caspase-1 and GSDMD (gasdermin-D), and production of IL-1ß and IL-18. We aimed to evaluate the expression of the inflammasome pathway in the skin of adults with AD. Thirty patients with moderate to severe AD and 20 healthy controls were enrolled in the study. We performed the analysis of the inflammasome components NLRP1, NLRP3, AIM-2, IL-1ß, IL-18, Caspase-1, ASC, GSDMD, and CD68 expression (macrophage marker) by immunohistochemistry and immunofluorescence. The main findings included increased expression of NLRP3, NLRP1 and AIM-2 at dermal level of severe AD; augmented IL-18 and IL-1ß expression at epidermis of moderate and severe patients, and in the dermis of severe AD; augmented expression of ASC, caspase-1 and GSDMD in both epidermis and dermis of moderate and severe AD. We detected positive correlation between caspase-1, GSDMD and IL-1ß (epidermis) and caspase-1 (dermis) and AD severity; NLRP3, AIM-2 and IL-1ß, and NLRP3 with IL-18 in the epidermis; ASC, GSDMD and IL-1ß, and NLRP3, AIM-2, caspase-1, and IL-18 in the dermis. We also evidenced the presence of CD68+ macrophages secreting GSDMD, ASC and IL-1ß in moderate and severe AD. Cutaneous macrophages, early detected in moderate AD, have its role in the disease inflammatory mechanisms. Our study indicates a canonical activation pathway of inflammasomes, reinforced by the chronic status of inflammation in AD. The analysis of the inflammasome complex evidenced an imbalance in its regulation, with increased expression of the evaluated components, which is remarkably in severe AD, emphasizing its relevance as potential disease biomarkers and targets for immunomodulatory interventions.

Twist2 contributes to skin regeneration and hair follicle formation in mouse fetuses.

Unlike adult mammalian wounds, early embryonic mouse skin wounds completely regenerate and heal without scars. Analysis of the underlying molecular mechanism will provide insights into scarless wound healing. Twist2 is an important regulator of hair follicle formation and biological patterning; however, it is unclear whether it plays a role in skin or skin appendage regeneration. Here, we aimed to elucidate Twist2 expression and its role in fetal wound healing. ICR mouse fetuses were surgically wounded on embryonic day 13 (E13), E15, and E17, and Twist2 expression in tissue samples from these fetuses was evaluated via in situ hybridization, immunohistochemistry, and reverse transcription-quantitative polymerase chain reaction. Twist2 expression was upregulated in the dermis of E13 wound margins but downregulated in E15 and E17 wounds. Twist2 knockdown on E13 left visible marks at the wound site, inhibited regeneration, and resulted in defective follicle formation. Twist2-knockdown dermal fibroblasts lacked the ability to undifferentiate. Furthermore, Twist2 hetero knockout mice (Twist + /-) formed visible scars, even on E13, when all skin structures should regenerate. Thus, Twist2 expression correlated with skin texture formation and hair follicle defects in late mouse embryos. These findings may help develop a therapeutic strategy to reduce scarring and promote hair follicle regeneration.

Lysosomal dysfunction and overload of nucleosides in thymidine phosphorylase deficiency of MNGIE.

Inherited deficiency of thymidine phosphorylase (TP), encoded by TYMP, leads to a rare disease with multiple mitochondrial DNA (mtDNA) abnormalities, mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). However, the impact of TP deficiency on lysosomes remains unclear, which are important for mitochondrial quality control and nucleic acid metabolism. Muscle biopsy tissue and skin fibroblasts from MNGIE patients, patients with m.3243 A > G mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) and healthy controls (HC) were collected to perform mitochondrial and lysosomal functional analyses. In addition to mtDNA abnormalities, compared to controls distinctively reduced expression of LAMP1 and increased mitochondrial content were detected in the muscle tissue of MNGIE patients. Skin fibroblasts from MNGIE patients showed decreased expression of LAMP2, lowered lysosomal acidity, reduced enzyme activity and impaired protein degradation ability. TYMP knockout or TP inhibition in cells can also induce the similar lysosomal dysfunction. Using lysosome immunoprecipitation (Lyso- IP), increased mitochondrial proteins, decreased vesicular proteins and V-ATPase enzymes, and accumulation of various nucleosides were detected in lysosomes with TP deficiency. Treatment of cells with high concentrations of dThd and dUrd also triggers lysosomal dysfunction and disruption of mitochondrial homeostasis. Therefore, the results provided evidence that TP deficiency leads to nucleoside accumulation in lysosomes and lysosomal dysfunction, revealing the widespread disruption of organelles underlying MNGIE.

MiRNA-224-5p regulates the defective permeability barrier in sensitive skin by targeting claudin-5.

BACKGROUND: Sensitive skin is hypersensitive to various external stimuli and a defective epidermal permeability barrier is an important clinical feature of sensitive skin. Claudin-5 (CLDN5) expression levels decrease in sensitive skin. This study aimed to explore the impact of CLDN5 deficiency on the permeability barrier in sensitive skin and the regulatory role of miRNAs in CLDN5 expression. MATERIALS AND METHODS: A total of 26 patients were retrospectively enrolled, and the CLDN5 expression and permeability barrier dysfunction in vitro were assessed. Then miRNA-224-5p expression was also assessed in sensitive skin. RESULTS: Immunofluorescence and electron microscopy revealed reduced CLDN5 expression, increased miR-224-5p expression, and disrupted intercellular junctions in sensitive skin. CLDN5 knockdown was associated with lower transepithelial electrical resistance (TEER) and Lucifer yellow penetration in keratinocytes and organotypic skin models. The RNA-seq and qRT-PCR results indicated elevated miR-224-5p expression in sensitive skin; MiR-224-5p directly interacted with the 3`UTR of CLDN5, resulting in CLDN5 deficiency in the luciferase reporter assay. Finally, miR-224-5p reduced TEER in keratinocyte cultures. CONCLUSION: These results suggest that the miR-224-5p-induced reduction in CLDN5 expression leads to impaired permeability barrier function, and that miR-224-5p could be a potential therapeutic target for sensitive skin.