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1.
Skin Res Technol ; 30(7): e13830, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38951871

RESUMO

BACKGROUND: Consumer products such as electrical shavers exert a combination of dynamic loading in the form of pressure and shear on the skin. This mechanical stimulus can lead to discomfort and skin tissue responses characterised as "Skin Sensitivity". To minimise discomfort following shaving, there is a need to establish specific stimulus-response relationships using advanced tools such as optical coherence tomography (OCT). OBJECTIVE: To explore the spatial and temporal changes in skin morphology and microvascular function following an electrical shaving stimulus. METHODS: Ten healthy male volunteers were recruited. The study included a 60-s electrical shaving stimulus on the forearm, cheek and neck. Skin parameters were recorded at baseline, 20 min post stimulus and 24 h post stimulus. Structural and dynamic skin parameters were estimated using OCT, while transepidermal water loss (TEWL) was recorded to provide reference values for skin barrier function. RESULTS: At baseline, six of the eight parameters revealed statistically significant differences between the forearm and the facial sites, while only surface roughness (Rq) and reflectivity were statistically different (p < 0.05) between the cheek and neck. At 20 min post shaving, there was a significant increase in the TEWL values accompanied by increased blood perfusion, with varying magnitude of change dependent on the anatomical site. Recovery characteristics were observed 24 h post stimulus with most parameters returning to basal values, highlighting the transient influence of the stimulus. CONCLUSIONS: OCT parameters revealed spatial and temporal differences in the skin tissue response to electrical shaving. This approach could inform shaver design and prevent skin sensitivity.


Assuntos
Pele , Tomografia de Coerência Óptica , Humanos , Masculino , Tomografia de Coerência Óptica/métodos , Adulto , Pele/irrigação sanguínea , Pele/diagnóstico por imagem , Antebraço/irrigação sanguínea , Adulto Jovem , Microvasos/diagnóstico por imagem , Microvasos/fisiologia , Bochecha/irrigação sanguínea , Bochecha/diagnóstico por imagem , Perda Insensível de Água/fisiologia , Voluntários Saudáveis , Fenômenos Fisiológicos da Pele , Estimulação Elétrica , Pescoço/diagnóstico por imagem , Pescoço/irrigação sanguínea , Microcirculação/fisiologia
2.
Skin Res Technol ; 30(7): e13798, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38979975

RESUMO

BACKGROUND: Skin physiology seems to be influenced by dietary choices and body composition, although links between these factors remain poorly characterised. In the present manuscript, we elaborate on the potential relationships among food groups, body composition and skin physiology in omnivores and vegetarians. MATERIAL AND METHODS: This cross-sectional observational study involved 181 participants, 129 omnivores and 52 vegetarians. The main functions of the skin measured in our laboratory were transepidermal water loss, deep and superficial epidermal hydration, skin elasticity, and carotenoid content. Skin variables obtained from different body regions were made comparable by a new Proportional Skin Index calculated to respect their relative representativity. RESULTS: No statistical differences were found when comparing both groups' body composition and skin variables from different body regions, with the exception of the skin carotenoid content significantly higher in the vegetarian group (p < 0.001). CONCLUSION: Although dietary patterns significantly differed between groups, with vegetarians consuming fewer animal-derived products and more plant-based foods, multiple linear regression analysis revealed no differences or association between the dietary pattern and the skin physiology. These findings highlight the need for further research to elucidate the specific impact of diet and food groups and body composition on skin physiology.


Assuntos
Composição Corporal , Fenômenos Fisiológicos da Pele , Vegetarianos , Humanos , Composição Corporal/fisiologia , Feminino , Masculino , Adulto , Estudos Transversais , Pessoa de Meia-Idade , Dieta , Perda Insensível de Água/fisiologia , Pele , Carotenoides/metabolismo , Elasticidade/fisiologia , Adulto Jovem , Dieta Vegetariana
3.
Skin Res Technol ; 30(7): e13851, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39031521

RESUMO

BACKGROUND: Although non-invasive diagnostic methods are widely used to examine the nail apparatus (NA), studies in healthy ones are scarce, and analyzes were often conducted in small groups. In the literature, there are only a few reports on TOWL measurements. The results of TEWL studies in the proximal nailfold have not been published so far. MATERIALS AND METHODS: Based on a detailed interview and physical examination, 81 volunteers (40 women and 41 men) aged from 22 to 65 years were qualified for the study. In this study, the overall examination of the NA in relation to water loss was performed for the first time, regarding the hand (d, dominant; n, non-dominant) and finger types (number, start of count from thumbs) as well as sex and age. RESULTS: The average TEWL value in the entire group ranged from 7.53 c.u. in the finger nd4 to 11.09 c.u. in nd1. Both in the dominant and non-dominant hand, in the entire analyzed group, and taking into account gender, weak statistically significant relationships were observed between the finger type value and TEWL (p < 0.05).The TEWL values were lower moving away from the thumb, The average TOWL value in the entire group ranged from 5.01 c.u. in d1 to 7.34 c.u. in d5. Both in the dominant and non-dominant hand, in the entire analyzed group and considering gender, statistically significant relationships were observed between the type of finger and TOWL values (p < 0.05). The TOWL values were higher moving away from the thumb. Subsequently, the values of TOWL and TEWL did not depend on type of hand (dominant or non-dominant), sex and age. Weak and moderate statistically significant correlations were found between TEWL and TOWL values in the entire study group and in females, as well as in selected fingers in males (d2, nd2, d3, nd3, d5, nd5) (p < 0.05, r < 0.27). CONCLUSION: Non-invasive diagnostics such TEWL and TOWL measurements are useful to assess differences in structure and function between types of fingers. However, obtained results demand further studies.


Assuntos
Unhas , Perda Insensível de Água , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Perda Insensível de Água/fisiologia , Idoso , Adulto Jovem , Valores de Referência , Água Corporal , Dedos/fisiologia
4.
Skin Res Technol ; 30(7): eSRT13784, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39031931

RESUMO

BACKGROUND: Microneedles are tiny needles, typically ranging from tens to hundreds of micrometers in length, used in various medical procedures and treatments. The tested medical device named "CELLADEEP Patch" a dissolvable microneedle therapy system (MTS), made of hyaluronic acid and collagen. And the iontophoresis technique is also applied in the system. The study aimed to evaluate the effectiveness of the "CELLADEEP Patch" in skin improvement. METHODS: Ex vivo human-derived skin tissue models were used in this study and they were divided into three different groups, namely, the Untreated Group, the Negative Control Group, and the Test Group respectively. The Untreated Group received no treatment measures, the Negative Control Group was exposed to ultraviolet B radiation (UVB) irradiation, and the Test Group was exposed to UVB irradiation and treated with "CELLADEEP Patch". Skin moisture content, transdermal water loss, and skin elasticity were evaluated by three clinical devices. Additionally, histological staining and related mRNA expression levels were also analyzed. RESULTS: The results of skin moisture content, transdermal water loss, and skin elasticity evaluation consistently illustrated that the application of "CELLADEEP Patch" led to remarkable skin improvement. And the analysis of histological staining images also confirmed the effectiveness of the "CELLADEEP Patch", especially for increasing collagen density. Moreover, the upregulation of Collagen type 1 a (COL1A1) and hyaluronan synthase 3 mRNA expression and the decrease of Matrix metalloproteinase 1 (MMP-1) and Interleukin-1 beta (IL-1ß) mRNA expression reflected its wrinkle improvement, moisturizing and anti-inflammation function. CONCLUSION: "CELLADEPP Patch", the MTS combined with the iontophoresis technique, exhibits its effectiveness in moisturizing, skin elasticity improvement, and anti-inflammatory function when applied to ex vivo human-derived skin tissue models in experiments. The study has contributed to the understanding of the "CELLADEPP Patch" and laid the foundation for subsequent animal experiments and clinical trials.


Assuntos
Ácido Hialurônico , Iontoforese , Agulhas , Pele , Humanos , Ácido Hialurônico/administração & dosagem , Iontoforese/métodos , Iontoforese/instrumentação , Pele/efeitos da radiação , Colágeno , Elasticidade , Metaloproteinase 1 da Matriz/metabolismo , Interleucina-1beta/metabolismo , Raios Ultravioleta , Envelhecimento da Pele/efeitos da radiação , Perda Insensível de Água/efeitos da radiação , Adesivo Transdérmico , Colágeno Tipo I/metabolismo
5.
Nutrients ; 16(13)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38999848

RESUMO

BACKGROUND: Our search for plant-derived ceramides from sustainable sources led to the discovery of ceramides and glucosylceramides in wine lees. OBJECTIVE: This study evaluated the efficacy and safety of wine lees extract (WLE)-derived ceramides and glucosylceramides in enhancing skin barrier function. METHODS: A randomized, double-blind, placebo-controlled study was conducted with 30 healthy Japanese subjects aged 20-64. Subjects were allocated to receive either the WLE-derived ceramides and glucosylceramides (test group) or placebo for 12 weeks. The primary outcome was transepidermal water loss (TEWL), and secondary outcomes included skin hydration, visual analog scale (VAS) of itching sensation, and the Japanese Skindex-29. RESULTS: One participant withdrew for personal reasons, resulting in 29 subjects for data analysis (placebo n = 15; test n = 14). The test group showed a tendency of lower TEWL compared to the placebo after 8 weeks (p = 0.07). Furthermore, after 12 weeks of administration, the test group had significantly lower TEWL than the placebo (p = 0.04). On the other hand, no significant differences were observed in the secondary outcome parameters. No adverse events related to the supplements were reported. CONCLUSIONS: Oral supplementation of WLE-derived ceramides and glucosylceramides is a prominent and safe approach to enhancing skin barrier function and health. TRIAL REGISTRATION: (UMIN000050422).


Assuntos
Ceramidas , Glucosilceramidas , Extratos Vegetais , Pele , Humanos , Método Duplo-Cego , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , Administração Oral , Extratos Vegetais/farmacologia , Extratos Vegetais/administração & dosagem , Adulto Jovem , Pele/efeitos dos fármacos , Glucosilceramidas/administração & dosagem , Glucosilceramidas/farmacologia , Vinho/análise , Perda Insensível de Água/efeitos dos fármacos
6.
J Drugs Dermatol ; 23(6): 466-471, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38834224

RESUMO

Xerosis is experienced by almost everyone at some time in their lives and the foundation of management of dry skin (both consumer- and healthcare professional--directed) rests on the use of moisturizers. Given the wide range of available moisturizers, counseling patients about selecting the optimum moisturizer for their individual situation relies on knowledge of ingredients and formulations. Traditionally, the main focus for many moisturizers centered on the core functional and structural role of ceramides within the epidermal barrier.  However, while a key aspect of transepidermal water loss and other skin barrier functions, components other than ceramides are equally essential in increasing moisturization. The skin's natural moisturizing factors (NMFs) are a complex mixture of water-attracting compounds such as amino acids, urea, lactate, pyrrolidone carboxylic acid (PCA), and electrolytes which play a fundamental role in preserving physiologic function by regulating the water content of the stratum corneum. By facilitating water retention, NMFs contribute significantly to the suppleness, elasticity, normal desquamation, and overall integrity of the skin barrier. Incorporation of NMFs into moisturizers addresses critical deficiencies in the skin's moisture balance that exist in xerotic and atopic skin, and in many skin disorders, mitigating signs and symptoms associated with xerosis and promoting optimal skin health. The biochemical composition of NMFs and the intricate interplay with epidermal homeostasis translate to a central role in moisturizers used for prophylactic and therapeutic management of various dry skin conditions, beyond ceramides alone. J Drugs Dermatol. 2024;23(6):466-471.     doi:10.36849/JDD.8358.


Assuntos
Ceramidas , Emolientes , Perda Insensível de Água , Humanos , Ceramidas/administração & dosagem , Perda Insensível de Água/efeitos dos fármacos , Emolientes/administração & dosagem , Creme para a Pele/administração & dosagem , Administração Cutânea , Epiderme/efeitos dos fármacos , Epiderme/metabolismo , Epiderme/fisiologia , Ureia/administração & dosagem
7.
Skin Res Technol ; 30(6): e13745, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38853249

RESUMO

INTRODUCTION: Psychological stress alters epidermal barrier function. While intensive studies on the underlying mechanism have been performed in mice, human studies are limited. Non-invasive skin-physiology measures have not yet been directly linked to non-invasive psycho-physiological assessments. METHODS: Standard measures of (I) transepidermal water loss prior to and after experimental barrier perturbation via tape stripping, (II) skin surface pH, (III) electrodermal activity, and (IV) heart rate function were taken over a 24 h time period. To document perceived stress, a standardized stress self-assessment questionnaire, namely the Trierer Inventar zum chronischen Stress (TICS), was utilized. RESULTS: Twenty healthy, Caucasian (Fitzpatrick skin phototype I-II), female volunteers (21-32 years, mean age 27, SD = 3.67 years) were included in this study (random sample). Significant correlations were shown for 24 h delta transepidermal water loss changes, that is, barrier repair kinetics (sympathetic activity) and heart rate variability (parasympathetic activity). Further correlations were noted for electrodermal activity and skin surface pH. Perceived stress, as documented by the TICS questionnaire, did not correlate with psycho- and skin physiological parameters, respectively. CONCLUSION: The presented approaches may provide a basis for non-invasive objective research on the correlation between psychological stressors and epidermal barrier function.


Assuntos
Resposta Galvânica da Pele , Frequência Cardíaca , Fenômenos Fisiológicos da Pele , Estresse Psicológico , Perda Insensível de Água , Humanos , Feminino , Adulto , Estresse Psicológico/fisiopatologia , Frequência Cardíaca/fisiologia , Perda Insensível de Água/fisiologia , Adulto Jovem , Resposta Galvânica da Pele/fisiologia , Concentração de Íons de Hidrogênio , Pele
8.
J Oleo Sci ; 73(7): 1015-1026, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38945920

RESUMO

Herein, we evaluated friction dynamics of human skin treated with polyacrylic acid aqueous solutions or gel creams using a sinusoidal motion friction evaluation system to demonstrate the effect of treatment with polymer aqueous solutions on human skin. A polymer aqueous solution or gel cream was applied to the inner forearms of 10 subjects to evaluate temporal changes in friction force under sinusoidal motion. Water content, skin viscoelasticity, and transepidermal water loss were also simultaneously measured to determine the effects on skin conditions. When human skin was treated with the polymer aqueous solution, the friction coefficient immediately after treatment was 0.69-0.99 and the delay time δ, a normalized parameter of the time difference in the delayed response of friction to the movement of the contact probe divided by the friction time T 0 for one round trip, was 0.171-0.179, which was greater than that of untreated skin. This increase was caused by the swelling and softening of the stratum corneum caused by the penetration of water in the polymer aqueous solution, which increased true contact area between the skin and contact probe. A significant difference was observed in the friction coefficient of the skin immediately after treatment with different polymer aqueous solutions. Among polymers (P1-P4), P4, which has a low-salt resistance and low yield stress, had the lowest friction coefficient because of collapsing of the polymer network structures by shearing and reduced viscosity owing to salts on human skin. The skin treated with a gel cream also exhibited a greater friction coefficient than the untreated skin immediately after treatment and 90 min later. This phenomenon can be caused by the occlusive effect of the oil in the gel cream.


Assuntos
Resinas Acrílicas , Fricção , Soluções , Água , Humanos , Viscosidade , Resinas Acrílicas/química , Pele/efeitos dos fármacos , Elasticidade , Adulto , Feminino , Masculino , Polímeros/química , Creme para a Pele/química , Géis , Perda Insensível de Água/efeitos dos fármacos
9.
Arch Dermatol Res ; 316(6): 329, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38829483

RESUMO

Dry skin is a common dermatological condition that frequently affects the elderly. A contributing cause to dry skin is a reduced concentration of hyaluronic acid (HA) in both the epidermis and dermis. The effectiveness of moisturizer containing HA as a therapy for dry skin is impacted by its specific molecular weight. Low molecular weight HA (LMWHA) is believed to be more effective in replenishing skin hydration in aging skin compared to High Molecular Weight HA (HMWHA) due to its ability to penetrate the stratum corneum. However, there is a lack of clinical research supporting this claim. A double-blind, randomized controlled trial was conducted on 36 residents of a nursing home in Jakarta. The participants, aged between 60 and 80 years, had been diagnosed with dry skin. Each test subject was administered three distinct, randomized moisturizing lotions (LMWHA, HMWHA, or vehicle), to be topically applied to three separate sites on the leg. Skin capacitance (SCap), transepidermal water loss (TEWL), and specified symptom sum score (SRRC) were measured at weeks 0, 2, and 4. After four weeks of therapy, area that was treated with LMWHA showed greater SCap values compared to the area treated with HMWHA (56.37 AU vs. 52.37 AU, p = 0.004) and vehicle (56.37 AU vs. 49.01 AU, p < 0.001). All groups did not show any significant differences in TEWL and SRRC scores. No side effects were found in all groups. The application of a moisturizer containing LMWHA to the dry skin of elderly resulted in significant improvements in skin hydration compared to moisturizers containing HMWHA and vehicle. Furthermore, these moisturizers demonstrated similar safety in treating dry skin in the elderly. ClinicalTrials.gov Identifier NCT06178367, https://clinicaltrials.gov/study/NCT06178367 .


Assuntos
Ácido Hialurônico , Peso Molecular , Humanos , Ácido Hialurônico/administração & dosagem , Idoso , Método Duplo-Cego , Feminino , Masculino , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade , Resultado do Tratamento , Perda Insensível de Água/efeitos dos fármacos , Envelhecimento da Pele/efeitos dos fármacos , Dermatopatias/tratamento farmacológico , Dermatopatias/diagnóstico , Administração Cutânea , Creme para a Pele/administração & dosagem , Emolientes/administração & dosagem
10.
J Therm Biol ; 122: 103864, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38852487

RESUMO

When amphibians thermoregulate, they face a fundamental trade-off between the ability to maintain activity and an increased rate of dehydration at higher temperatures. Canopy coverage affects both the thermal and hydric conditions of the environment and can therefore influence amphibian thermoregulation. Frogs require proper conditions to thermoregulate to successfully grow, survive, and reproduce. But while we know how canopy and environmental variables typically affect operative temperature, less is known about effects on amphibian water loss rates. In this study, we measure the effect of canopy coverage on the conditions available for thermoregulation at a breeding pond of the California red-legged frog, Rana draytonii. We use agar frog models to estimate the thermal and hydric capacities frogs would experience in locations with different canopy coverage and microhabitats. At each site, we deployed models under four microhabitat treatments: wet/sun, wet/shade, dry/sun, and dry/shade. We modeled how environmental variables affected operative temperature and evaporative water loss from agar frogs. We found positive effects of air temperature, the sun treatment, and reduced canopy cover on operative temperature, and negative direct or indirect effects of these variables on evaporative water loss, consistent with the hypothesized trade-off between thermoregulatory behavior to increase temperature and the increased desiccation risk due to higher water loss. Additionally, our results indicate that the availability of wet microhabitats can allow frogs to reduce water loss, potentially mitigating the risk of desiccation when thermoregulating to achieve higher operative temperatures. Our findings suggest, that with access to proper microhabitats, amphibians can mitigate the fundamental trade-off and receive benefits of thermoregulating at high temperatures.


Assuntos
Regulação da Temperatura Corporal , Ecossistema , Animais , Ranidae/fisiologia , Perda Insensível de Água , Temperatura , Modelos Biológicos
11.
Pharm Res ; 41(6): 1149-1161, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38720033

RESUMO

BACKGROUND: The in vitro permeation test (IVPT) using ex vivo human skin is a sensitive and robust model system that has been vital in elucidating the fundamental parameters surrounding the absorption of both therapeutic agents and industrial chemicals through skin. FDA and OECD IVPT Guidances recommend that each skin section selected for study should be screened prior to use to ensure that the stratum corneum integrity is retained. Three methods are currently considered acceptable: 1) transepidermal water loss (TEWL), 2) electrical resistance, and 3) tritiated water (3H2O) absorption. METHODS: A retrospective analysis of data from the authors' laboratory has been performed with the objective of addressing a number of questions regarding the 3H2O and TEWL integrity tests, and the population attributes of a large database consisting of 17,330 individual skin sections obtained from 459 skin donors. The applicability and usefulness of these tests, when compared to companion permeation data obtained from 25 topical drug products, has also been examined. RESULTS: Both integrity tests found water permeability to be equal in White and Hispanic races but higher than in Blacks, 3H2O being more discriminating than TEWL. Male skin is more permeable than female and there is a slight decrease in permeability with advancing age in both groups. Correlation between 3H2O absorption and drug absorption revealed a minimal relationship between the two in most cases, the Pearson correlation coefficient ranging from -0.417 to 0.953. Additionally, drug outliers were not always identified with a failing integrity test. CONCLUSION: The results call for a critical reexamination of the value of the 3H2O integrity test, and by extension, TEWL, for use in IVPT studies.


Assuntos
Permeabilidade , Absorção Cutânea , Pele , Água , Humanos , Feminino , Masculino , Pele/metabolismo , Água/metabolismo , Adulto , Pessoa de Meia-Idade , Estudos Retrospectivos , Idoso , Perda Insensível de Água , Adulto Jovem , Adolescente , Técnicas In Vitro , Idoso de 80 Anos ou mais , Impedância Elétrica
12.
Ecol Evol Physiol ; 97(2): 118-128, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38728691

RESUMO

AbstractCutaneous evaporative water loss (CEWL) makes up a significant portion of total evaporative water loss in many terrestrial vertebrates. CEWL changes on evolutionary and acclimatory timescales in response to temperature and humidity. However, the lability of CEWL on acute timescales is unknown. To examine this, we increased or decreased body temperatures of western fence lizards (Sceloporus occidentalis) over a 15-min period while continuously recording CEWL with a handheld evaporimeter. CEWL increased in response to heating and decreased in response to cooling on the order of seconds. However, CEWL was different between heating and cooling groups at a common body temperature. We observed the same positive relationship between CEWL and body temperature, as well as the difference in CEWL between treatments, for deceased lizards that we opportunistically measured. However, deceased lizards had more extreme CEWL values for any given body temperature and treatment. Overall, our results suggest that both structural traits and active physiological processes likely influence the rates and plasticity of CEWL.


Assuntos
Lagartos , Temperatura , Perda Insensível de Água , Animais , Lagartos/fisiologia , Perda Insensível de Água/fisiologia , Temperatura Corporal/fisiologia , Masculino , Fenômenos Fisiológicos da Pele
14.
Ital J Dermatol Venerol ; 159(3): 349-356, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38635324

RESUMO

BACKGROUND: The pathophysiology of sensitive skin is largely unknown and no univocal data on the role of the epidermal barrier impairment have been identified. The aim of this study was to assess whether subjects with or without sensitive skin differ for some biophysical skin parameters, which reflect skin barrier integrity or skin hyperactivity. METHODS: This observational, cross-sectional study included adult volunteers not affected with chronic inflammatory skin diseases who attended the Unit of Dermatology and the Center of Cosmetology of the University of Ferrara, Ferrara, Italy, between March 2021 and November 2022. All subjects, subdivided into those with or without sensitive skin, based on either Lactic Acid Stinging Test (LAST) result or a questionnaire-based skin sensitivity score ≥4, were tested for transepidermal water loss (TEWL), skin elasticity and hydrations and dermographism. RESULTS: One hundred and eighty-seven subjects were included. No significant differences in terms of TEWL, elasticity and hydration levels were recorded between subjects with sensitive skin and those without, subdivided according to both the LAST result and the questionnaire score. Dermographism was elicited more in subjects with sensitive skin than in the others, although without statistical significance. CONCLUSIONS: The study failed to find significant biophysical differences between sensitive and non-sensitive skin. Therefore, the role of skin barrier impairment does not appear to be a necessary condition in determining an abnormal skin sensitivity to potentially unpleasant and irritating stimuli. These findings indirectly support the relevance of a peripheral sensory neural hyperactivity in the pathophysiology of sensitive skin.


Assuntos
Epiderme , Perda Insensível de Água , Humanos , Estudos Transversais , Feminino , Masculino , Adulto , Perda Insensível de Água/fisiologia , Pessoa de Meia-Idade , Epiderme/fisiopatologia , Elasticidade , Idoso , Adulto Jovem
15.
Eur J Pharm Biopharm ; 199: 114303, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38657740

RESUMO

Dissolvable microneedles (DMNs), fabricated from biocompatible materials that dissolve in both water and skin have gained popularity in dermatology. However, limited research exists on their application in compromised skin conditions. This study compares the hyaluronic acid-based DMNs penetration, formation of microchannels, dissolution, and diffusion kinetics in intact, barrier-disrupted (tape stripped), and dry (acetone-treated) porcine ear skin ex vivo. After DMNs application, comprehensive investigations including dermoscopy, stereomicroscope, skin hydration, transepidermal water loss (TEWL), optical coherence tomography (OCT), reflectance confocal laser scanning microscopy (RCLSM), confocal Raman micro-spectroscopy (CRM), two-photon tomography combined with fluorescence lifetime imaging (TPT-FLIM), histology, and scanning electron microscopy (SEM) were conducted. The 400 µm long DMNs successfully penetrated the skin to depths of ≈200 µm for dry skin and ≈200-290 µm for barrier-disrupted skin. Although DMNs fully inserted into all skin conditions, their dissolution rates were high in barrier-disrupted and low in dry skin, as observed through stereomicroscopy and TPT-FLIM. The dissolved polymer exhibited a more significant expansion in barrier-disrupted skin compared to intact skin, with the smallest increase observed in dry skin. Elevated TEWL and reduced skin hydration levels were evident in barrier-disrupted and dry skins compared to intact skin. OCT and RCLSM revealed noticeable skin indentation and pronounced microchannel areas, particularly in barrier-disrupted and dry skin. Additional confirmation of DMN effects on the skin and substance dissolution was obtained through histology, SEM, and CRM techniques. This study highlights the impact of skin condition on DMN effectiveness, emphasizing the importance of considering dissolvability and dissolution rates of needle materials, primarily composed of hyaluronic acid, for optimizing DMN-based drug delivery.


Assuntos
Administração Cutânea , Ácido Hialurônico , Agulhas , Absorção Cutânea , Pele , Solubilidade , Animais , Suínos , Pele/metabolismo , Pele/efeitos dos fármacos , Absorção Cutânea/efeitos dos fármacos , Absorção Cutânea/fisiologia , Ácido Hialurônico/química , Ácido Hialurônico/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Tomografia de Coerência Óptica/métodos , Microinjeções/métodos , Perda Insensível de Água/efeitos dos fármacos , Perda Insensível de Água/fisiologia , Materiais Biocompatíveis/administração & dosagem , Materiais Biocompatíveis/química
16.
Br J Dermatol ; 191(1): 49-57, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38446755

RESUMO

BACKGROUND: In the general population randomized controlled trial PreventADALL, frequent emollient bath additives from 2 weeks of age did not prevent atopic dermatitis, while the effect on skin barrier function throughout infancy is not established. OBJECTIVES: The primary aim of this exploratory substudy was to assess the effect of mineral-based oil baths on transepidermal water loss (TEWL) and dry skin through infancy, and secondarily to explore if filaggrin (FLG) mutations modified the effect. METHODS: Overall, 2153 infants were included and randomized to either the 'Skin intervention' (SI) group (n = 995) (oil bath 4 times weekly from 2 weeks through 8 months) or 'No skin intervention' (NSI) group (n = 1158), with TEWL measurements at 3, 6 and/or 12 months of age. Information on FLG mutation status was available for 1683 of these infants. Effects of the skin intervention on TEWL and dry skin through infancy were assessed by mixed-effects regression modelling. Background characteristics and protocol adherence were collected from electronic questionnaires, birth records and weekly diaries. RESULTS: The TEWL (95% confidence interval) was on average 0.42 g m-2 h-1 (0.13-0.70, P = 0.004) higher in the SI group compared with the NSI group through the first year of life, with significantly higher levels at 3 months [8.6 (8.3-9.0) vs. 7.6 (7.3-7.9)], but similar at 6 and 12 months. Dry skin was observed significantly more often in the NSI group compared with the SI group at 3 months (59% vs. 51%) and at 6 months of age (63% vs. 53%), while at 12 months of age, the difference was no longer significant. At 3 months, the TEWL of FLG mutation carriers was similar to the TEWL in the SI group. No interaction between SI and FLG mutation was found in the first year of life. CONCLUSIONS: Infants given frequent oil baths from 2 weeks of age had reduced skin barrier function through infancy compared with controls, largely attributed to higher TEWL at 3 months of age, while the skin at 3 and 6 months appeared less dry in infants subjected to the skin intervention.


Atopic dermatitis (AD) affects approximately 20% of children in industrialized countries. AD causes dry, itchy skin and can increase the chance of infections. This study was a substudy of the large Scandinavian PreventADALL trial, including 2394 infants, recruited from the general population between 2014 and 2016. Children in this trial were allocated randomly to receive either a skin intervention, food intervention, combined intervention, or no intervention. Children were examined at 3, 6 and 12 months of age. The examinations involved an investigation of the skin, to evaluate dry skin and skin barrier function by transepidermal water loss (TEWL) in the outer layers of the skin (higher TEWL suggests decreased skin barrier function). The skin intervention consisted of oil baths at least 4 times per week from 2 weeks of age through 8 months of age, and have previously not been shown to prevent AD by 1 and 3 years of age. We aimed to investigate whether frequent oil baths had any effect on TEWL and dry skin. We found that the skin intervention increased TEWL in the first year of life, especially at 3 months of age. Dry skin was less common in the skin intervention groups compared with the groups with no skin intervention. Infants with mutations in the gene coding for a skin barrier protein, called filaggrin, were associated with increased TEWL; however, in the skin intervention group, TEWL was similar among the infants with or without filaggrin mutations. Our findings suggest that oil baths several times per week from early infancy transiently decreases skin barrier function.


Assuntos
Banhos , Dermatite Atópica , Emolientes , Proteínas Filagrinas , Proteínas de Filamentos Intermediários , Mutação , Perda Insensível de Água , Humanos , Perda Insensível de Água/efeitos dos fármacos , Banhos/métodos , Lactente , Feminino , Dermatite Atópica/prevenção & controle , Dermatite Atópica/genética , Masculino , Emolientes/administração & dosagem , Proteínas de Filamentos Intermediários/genética , Recém-Nascido , Óleo Mineral/administração & dosagem , Cuidado do Lactente/métodos , Higiene da Pele/métodos , Pele/efeitos dos fármacos
17.
Skin Res Technol ; 30(3): e13655, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38481085

RESUMO

BACKGROUND: The stratum corneum (SC), the outermost layer of the skin epidermis, acts as an effective bi-directional barrier, preventing water loss (inside-outside barrier) and entry of foreign substances (outside-inside barrier). Although transepidermal water loss (TEWL) is a widely-used measure of barrier function, it represents only inside-outside protection. Therefore, we aimed to establish a non-invasive method for quantitative evaluation of the outside-inside barrier function and visually present a skin barrier model. MATERIALS AND METHODS: Skin barrier damage was induced by applying a closed patch of 1% sodium dodecyl sulfate to the forearms of eight participants; they were instructed to apply a barrier cream on a designated damaged area twice daily for 5 days. The SC barrier was evaluated by measuring TEWL and fluorescein sodium salt penetration rate before, immediately after, and 5 days after damage. The penetration rate was assessed using tape-stripping (TS) technique and fluorescence microscopy. RESULTS: The rates of fluorescein sodium salt penetration into the lower layers of SC differed significantly based on the degree of skin barrier damage. The correlation between penetration rate and TEWL was weak after two rounds of TS and became stronger after subsequent rounds. Five days after skin barrier damage, the penetration rate of all layers differed significantly between areas with and without the barrier cream application. CONCLUSION: Our findings demonstrated that the penetration rate was dependent on skin barrier conditions. The penetration rate and corresponding fluorescence images are suitable quantitative indicators that can visually represent skin barrier conditions.


Assuntos
Dermatopatias , Perda Insensível de Água , Humanos , Fluoresceína/metabolismo , Fluoresceína/farmacologia , Epiderme/metabolismo , Pele/metabolismo , Dermatopatias/metabolismo , Água/metabolismo , Emolientes/farmacologia
18.
Cont Lens Anterior Eye ; 47(3): 102154, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38523013

RESUMO

Dry eye disease is a progressive prevalent ocular surface disorder that arises from various factors and is characterized by insufficient quality and/or quantity of tears. The underlying pathophysiology is intricate and can progress to chronic, difficult-to-treat conditions. Multiple strategies and therapeutic approaches are utilized in its management that target one or more etiopathological components of dry eyes, which may include aqueous tear deficiency or evaporative dry eyes. The primary focus of this paper is on treatment alternatives that utilize lipids for the treatment of evaporative dry eyes. This may arise from either abnormal lipid production or inadequate lipid spreading caused by meibomian gland dysfunction. The hypothesis behind the development of these lipid-containing eye drops is that if they can imitate the lipid layer, they may be able to help in the management of the signs and symptoms of evaporative dry eyes. The lipids used in commercial formulations for dry eyes are mineral oil, castor oil, phospholipids, omega-3 fatty acid, and medium-chain triglycerides. The literature suggests the potential of lipid-containing eye drops to alleviate some of the signs and symptoms and enhance the quality of life for individuals suffering from evaporative dry eyes.


Assuntos
Síndromes do Olho Seco , Lipídeos , Soluções Oftálmicas , Lágrimas , Síndromes do Olho Seco/tratamento farmacológico , Síndromes do Olho Seco/fisiopatologia , Humanos , Lágrimas/química , Lágrimas/metabolismo , Perda Insensível de Água/efeitos dos fármacos
19.
Artigo em Inglês | MEDLINE | ID: mdl-38452971

RESUMO

In terrestrial vertebrates, the outermost layer of the skin, the stratum corneum (SC), provides a durable and flexible interface with the environment and is comprised of corneocytes embedded in lipids. However, the morphology and lipid composition of the SC varies throughout evolutionary history. Because crocodilians and birds phylogenetically bracket the Archosaurian clade, lipid composition in crocodilian SC may be compared with that of birds and other vertebrates to make inferences about broader phylogenetic patterns within Archosaurs while highlighting adaptations in vertebrate skin. We identified and quantified lipid classes in the SC of the American Alligator (Alligator mississippiensis) from three skin regions varying in mobility. Our results find similarities in lipid composition between alligator and avian SC, including a high percentage of cerebrosides, a polar lipid previously found only in the SC of birds and bats. Furthermore, polar lipids were more abundant in the most mobile region of the SC. Because polar lipids bind with water to increase skin hydration and therefore its pliability under physical stress, we hypothesize that selection for lipids in Archosaurian SC was driven by the unique distribution of proteins in the SC of this clade, and cerebrosides may have served as pre-adaptations for flight.


Assuntos
Jacarés e Crocodilos , Quirópteros , Animais , Filogenia , Lipídeos , Perda Insensível de Água/fisiologia , Epiderme/metabolismo , Aves , Cerebrosídeos/metabolismo
20.
Ann Allergy Asthma Immunol ; 132(6): 678-685, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38360106

RESUMO

OBJECTIVE: Skin barrier defects are one of the primary causes of atopic dermatitis (AD). The basis of skin barrier defects in AD is due to a deficiency in various barrier proteins including filaggrin, involucrin, claudins, and lipids such as ceramide, fatty acids, and cholesterol. This review updates a more detailed lipid dysregulation in the skin barrier of AD based on recent lipidomic analysis. The clinical implications, treatments, prevention, and predictive capability of skin barrier defects are also reviewed. DATA SOURCES: Published literature obtained through PubMed searches. STUDY SELECTIONS: Studies relevant to the mechanisms, clinical implications, treatments, prevention, and predictors of AD development. RESULTS: Skin barrier defects contribute to transepidermal water loss, infections, IgE sensitizations, and cutaneous inflammation in AD. Preventive treatments include daily hydration and application of moisturizers. Because skin barrier defects precede the development of AD, they provide an opportunity for prediction and intervention. CONCLUSION: Skin barrier defects play an important role in the comorbidities of AD including infectious complications, disease flare, and allergic diathesis. Current research focuses on prevention and prediction of AD development.


Assuntos
Dermatite Atópica , Proteínas Filagrinas , Pele , Humanos , Pele/metabolismo , Pele/imunologia , Pele/patologia , Perda Insensível de Água/efeitos dos fármacos
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