Dépouillements

Some thoughts about Anthony V. Rawlings and hydration and barrier function of the skin / Philip W. Wertz in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 488-493 Titre : Some thoughts about Anthony V. Rawlings and hydration and barrier function of the skin Type de document : texte imprimé Auteurs : Philip W. Wertz, Auteur Année de publication : 2024 Article en page(s) : p. 488-493 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée Céramides Un céramide est un sphingolipide résultant de la combinaison d'un acide gras avec la sphingosine via une liaison amide. On trouve de telles molécules en abondance dans les membranes cellulaires, où elles entrent notamment dans la constitution des sphingomyélines. Les céramides ne jouent pas qu'un rôle structurel dans les membranes biologiques, et peuvent également revêtir des fonctions de signalisation lipidique. Leurs actions les mieux comprises vont de la différenciation cellulaire à la mort cellulaire programmée (apoptose) en passant par la prolifération cellulaire. Les acides gras qui les constituent ont généralement un nombre pair (de 16 à 24) d'atomes de carbone, sont saturés ou monoinsaturés, et sont souvent α-hydroxylés. La plupart des céramides n'existent pas à l'état naturel si ce n'est comme précurseurs de la biosynthèse des sphingolipides par une réaction d'addition sur la fonction alcool primaire de la sphingosine. (Wikipedia) Cornéocytes Dermatologie Facteur naturel d'hydratation Involucrine L'involucrine est une protéine synthétisée dans le cytoplasme des kératinocytes du stratum granulosum. Elle n'est associée à aucune structure morphologiquement individualisable. Son gène est le IVL situé sur le chromosome 1 humain. La proportion relative de l'involucrine dans l’enveloppe cornée est de 2 %. Elle sert d’amorce à la fixation des autres molécules de l’enveloppe cornée, notamment de la loricrine et la kératine. L'involucrine entraine la mort de la cellule, ce qui va durcir la membrane. (Wikipedia) Membranes lipidiques Peau -- Anatomie Peau -- Physiologie Index. décimale : 612.7 Fonctions motrices et peau (tégument), cheveux et poils, ongles Note de contenu : - Physical properties of ceramides - Seasonal and age-dependent variation of stratum corneum lipids - Lipoxygenases and the corneocyte lipid envelope - Desquamation - Anatomic and racial variation in barrier function DOI : https://doi.org/10.1111/ics.12953 En ligne : https://drive.google.com/file/d/1lUM8muC-feIx5u4ssMVWxRerMciRz9qG/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41348 [article]

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Chondroitin/dermatan sulphate proteoglycan, desmosealin, showing affinity to desmosomes / Céline Laperdrix in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 494-505 Titre : Chondroitin/dermatan sulphate proteoglycan, desmosealin, showing affinity to desmosomes Type de document : texte imprimé Auteurs : Céline Laperdrix, Auteur ; Stéphane Duhieu, Auteur ; Marek Haftek, Auteur Année de publication : 2024 Article en page(s) : p. 494-505 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée Cellules -- Différenciation Epiderme Jonctions cellulaires Peau -- Anatomie Peau -- Physiologie Index. décimale : 668.5 Parfums et cosmétiques Résumé : - OBJECTIVE : Desmosomes are the most prominent interkeratinocyte junctions. The correct barrier function of stratified epithelia such as epidermis depends on their expression. During epidermal differentiation, the molecular composition of desmosomes evolves and so do their physical and chemical properties. Desquamation of corneocytes at the surface of the stratum corneum depends on an orderly degradation of desmosomes by endogenous enzymes. This process may be regulated by glycosylated molecules. We focused on the detection and characterization of potentially implicated players bearing ‘sugar’ characteristics. - METHODS : Using an original monoclonal antibody and biochemical methods, we partially characterized a proteoglycan of the exclusively chondroitin/dermatan sulphate type, secreted into the interkeratinocyte spaces, that is incorporated into the extracellular parts of desmosomes in quantities proportional to the degree of cell differentiation, as visualized with immuno-electron microscopy. - RESULTS : This antigen, that we named desmosealin, displays biochemical and immunocytochemical characteristics that clearly differentiate it from known desmosomal elements. Unlike so far described epidermal proteoglycans, which belong to the heparan sulphate family, desmosealin displays chondroitin/dermatan sulphate glycosaminoglycan chains. It can be detected within the extracellular ‘cores’ of desmosomes in the upper viable epidermal layers and in corneodesmosomes from the lowermost part of the stratum corneum. - CONCLUSION : Extensive integration of proteoglycans into the extracellular parts of desmosomes at the late stages of keratinocyte maturation is likely of functional importance. Given its biochemical profile, its pattern of expression in the epidermis and its desmosomal localization, desmosealin may emerge as a key element in the regulation of desmosome processing, epidermal cohesion and formation of a functional epidermal barrier. Note de contenu : - MATERIALS AND METHODS : - Tissue source and sample preparation - Immunoelectron microscopy - Antibodies and reactants - Protein extraction - Western blotting - Two-dimensional electrophoresis - Size exclusion chromatography - Chemical deglycosylation - Enzymatic deglycosylation - Immunoprecipitation assays - Mass spectrometry - Molecular biology - RESULTS : - Interkeratinocyte spaces, including extracellular portions of desmosomes, contain an antigen reacting with KM48 MAb - Desmosealin co-localizes with desmoglein 1 and corneodesmosin in the extracellular portions of desmosomes and corneodesmosomes, respectively - KM48 MAb detects high molecular mass proteins recovered from normal human epidermal cells with mild detergent-containing buffers - Two-dimensional immunoblot resolution of the KM48 antigen confirms the unique biochemical characteristics of desmosealin - KM48 MAb recognizes a non-glycosylated epitope of the highly glycosylated desmosealin, and this binding is not dependent on the pentameric nature of the IgM antibody - Inhibition of GAG attachment in organotypic cultures of human keratinocytes results in the production of a non-glycosylated 72 kDa form of desmosealin - Desmosealin molecules are sensitive to digestion with specific glycosidases indicating the dermatan sulphate/chondroitin sulphate nature of the GAG chains - Immunoprecipitation studies confirm that the antibodies used in this study, including KM48 MAb, recognize different proteoglycans DOI : https://doi.org/10.1111/ics.12954 En ligne : https://drive.google.com/file/d/1QIUsK8BuMQvB4z2V2sPLkaBO5Tv_isgJ/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41349 [article]

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Topically applied, fatty acid-containing formulations provide superior barrier benefits in an ex vivo tape-stripped skin model / John Nip in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 506-515 Titre : Topically applied, fatty acid-containing formulations provide superior barrier benefits in an ex vivo tape-stripped skin model Type de document : texte imprimé Auteurs : John Nip, Auteur ; Hilal Ilarslan, Auteur ; Ana Villa, Auteur ; Dawn Mihalov, Auteur ; Manoj Misra, Auteur ; Samantha D. Samaras, Auteur ; Lin Feng, Auteur ; Stella Arcella, Auteur ; John Bajor, Auteur ; Andrew E. Mayes, Auteur Année de publication : 2024 Article en page(s) : p. 506-515 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Acides gras Barrière cutanée Couche cornée Dermo-cosmétologie Dermo-pharmacie Etude ex vivo Formulation (Génie chimique) Lamelles lipidiques Lipides Index. décimale : 668.5 Parfums et cosmétiques Résumé : - OBJECTIVE : Ex vivo skin has been used to study various skin conditions from atopic dermatitis to burn injury. The aim of this research is to identify a more effective barrier improvement strategy and to evaluate topical formulations in replenishing the skin. The skin can create new longer chain fatty acids and ceramides (CERs) from topically applied skin natural fatty acid to help renew the skin's barrier. - METHODS : An ex vivo skin model damaged by sequential tape stripping of the stratum corneum (SC) was used to investigate the repair of the SC. Confocal laser scanning microscopy was used to assess the SC layers recovered. Ultrastructural analysis was performed using transmission electron microscopy to visualize the lamellar bodies and intercellular lipid lamellae. - RESULTS : The data in this study provide the first direct ex vivo evidence comparing different marketed formulations containing three CERs with those containing fatty acids. Free fatty acid (FFA)-containing formulations, but not CER-containing formulations, directly applied to the damaged skin, showed an increased number of repaired SC layers and this was reflected at the ultrastructural level by an increased intercellular lipid lamellae length and an increased number of lamellar bodies. - CONCLUSION : These findings demonstrate that FFA-containing formulations can repair damaged ex vivo skin and point to a repair mechanism in which topically applied palmitic and stearic acids, (which boost lipid levels and elongation) can increase the production and transport of lipids into a repaired SC and thus rebuild an effective skin barrier. Note de contenu : - MATERIALS AND METHODS : Formulations - Ex vivo skin, tape-stripping and treatment - Biopsies of treated areas - Biopsy collection and processing for histology and cornified layer analysis - H&E staining of sections - Immunohistochemistry for Ki67 - Imaging and quantitation of epidermal area and Ki67 staining - Corneocyte layer quantification - Sample preparation for transmission electron microscopy (TEM) - Quantitative analysis of lamellar bodies (LB) and intercellular lipid lamellae (ICLL) - Statistical analyses - RESULTS : Ex vivo skin response to tape stripping - Removal of SC and its recovery in ex vivo skin - Topical free fatty acid-containing formulations (FFA) increased SC layer recovery - Topical free fatty acid-containing formulations (FFA) increased intercellular lipid lamella (ICLL) formation and length - Topical FFA treatment stimulates lamellar body production and secretion DOI : https://doi.org/10.1111/ics.12961 En ligne : https://drive.google.com/file/d/1dBCIelfqOUS_L1KmdXWBuOYVPw4fintT/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41350 [article]

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Effects of eczema calming lotion on the stratum corneum in atopic dermatitis : Corneodesmosin and intercellular lipid lamellae / Hilal Ilarslan in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 516-525 Titre : Effects of eczema calming lotion on the stratum corneum in atopic dermatitis : Corneodesmosin and intercellular lipid lamellae Type de document : texte imprimé Auteurs : Hilal Ilarslan, Auteur ; William F. Lathrop, Auteur ; Brian Dobkowski, Auteur ; Stacy S. Hawkins, Auteur ; Jane Scott, Auteur ; John Bajor, Auteur ; Andrew E. Mayes, Auteur Année de publication : 2024 Article en page(s) : p. 516-525 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée cornéodesmosine La cornéodesmosine est synthétisée au sein des kératinocytes épineux supérieurs. Sécrétée par l’intermédiaire des corps lamellaires, la cornéodesmosine est secondairement incorporée au niveau du cÅ“ur des desmosomes. Il s’agit de la seule protéine identifiée à ce jour comme étant spécifique des cornéodesmosomes. Son contenu riche en résidus sérine et glycine s'organisant en boucles souples est compatible avec des fonctions d’adhésion. (https://biologiedelapeau.fr/) Cornéosomes Couche cornée Dermo-cosmétologie Dermo-pharmacie Eczéma constitutionnel Lamelles lipidiques Microscopie confocale à balayage laser Peau -- Soins et hygiène Index. décimale : 668.5 Parfums et cosmétiques Résumé : - OBJECTIVE : Atopic dermatitis (AD) is characterized by compositional and structural changes to the skin at lesional sites. Alteration to the levels and organization of both protein and lipid components are associated with disease status and lead to impaired barrier and hydration. Corneodesmosin (CDSN) and the arrangement and length of the intercellular lipid lamellae (ICLL) are altered in disrupted skin states. The aim of this research was to profile the distribution of CDSN and the ICLL in the stratum corneum (SC) at lesional and non-lesional sites in AD-prone skin and to investigate the impact of an eczema calming lotion containing petroleum jelly, fatty acids, and colloidal oatmeal. - METHODS : An IRB-approved study was conducted with participants with active AD. From a small subset of participants, tape strips were collected from lesional and non-lesional sites on the arm, prior to and after twice daily application, over 4 weeks of an eczema calming lotion containing petroleum jelly, fatty acids, and colloidal oatmeal. Fluorescent antibody staining was used to investigate the distribution of CDSN. Transmission electron microscopy (TEM) was used to characterize the ICLL. - RESULTS : The distribution/coverage of CDSN was similar between lesional and non-lesional sites at baseline ; application of the lotion resulted in a more defined honeycomb/peripheral distribution. Normalized ICLL (nICLL) was lower in baseline samples from lesional sites relative to non-lesional sites. Application of the lotion increased this parameter by the end of the study at all sites. - CONCLUSION : The eczema calming lotion containing petroleum jelly, fatty acids and colloidal oatmeal provided changes in corneodesmosomal proteins distribution and ICLL, consistent with improvements in corneocyte maturation and improved barrier function in the skin of individuals with atopic dermatitis. Note de contenu : - MATERIALS AND METHODS : Corneodesmosin staining - Sample preparation for TEM and quantitative analysis of ICLL - RESULTS : Corneodesmosin distribution DOI : https://doi.org/10.1111/ics.12962 En ligne : https://drive.google.com/file/d/1M-QgBKcqyi-7NVjWZjqxDYyG3lIJB5xO/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41351 [article]

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The role of ceramides in skin barrier function and the importance of their correct formulation for skincare applications / Jennifer Schild in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 526-543 Titre : The role of ceramides in skin barrier function and the importance of their correct formulation for skincare applications Type de document : texte imprimé Auteurs : Jennifer Schild, Auteur ; Aneta Kalvodová, Auteur ; Jarmila Zbytovská, Auteur ; Mike Farwick, Auteur ; Cornelia Pyko, Auteur Année de publication : 2024 Article en page(s) : p. 526-543 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée Céramides Un céramide est un sphingolipide résultant de la combinaison d'un acide gras avec la sphingosine via une liaison amide. On trouve de telles molécules en abondance dans les membranes cellulaires, où elles entrent notamment dans la constitution des sphingomyélines. Les céramides ne jouent pas qu'un rôle structurel dans les membranes biologiques, et peuvent également revêtir des fonctions de signalisation lipidique. Leurs actions les mieux comprises vont de la différenciation cellulaire à la mort cellulaire programmée (apoptose) en passant par la prolifération cellulaire. Les acides gras qui les constituent ont généralement un nombre pair (de 16 à 24) d'atomes de carbone, sont saturés ou monoinsaturés, et sont souvent α-hydroxylés. La plupart des céramides n'existent pas à l'état naturel si ce n'est comme précurseurs de la biosynthèse des sphingolipides par une réaction d'addition sur la fonction alcool primaire de la sphingosine. (Wikipedia) Cosmétiques Dermo-cosmétologie Emulsions -- Emploi en cosmétologie Formulation (Génie chimique) Peau -- Anatomie Peau -- Physiologie Peau -- Soins et hygiène Index. décimale : 668.5 Parfums et cosmétiques Résumé : Ceramides are a family of lipids constituted by a sphingoid base and a fatty acid. In the skin, they are mainly present in the stratum corneum where, with cholesterol and free fatty acids, they constitute the inter-corneocyte lipids. With the other lipid groups, they play a key role in the formation of dense lamellar structures between adjacent corneocytes, collectively ensuring the vital efficient barrier to water evaporation and protection from foreign agents´ penetration. Changes in ceramide level and relative composition, with potential impairment of lipid arrangement, have been evidenced in different skin conditions and skin diseases. Therefore, use of suitably formulated ceramides has been proposed for topical treatment to help re-structure damaged lipid arrangement and repair impaired skin barrier function. Nonetheless, the formulation of ceramides in products necessitates specific processes such as heating to high temperature before their introduction in the final formula. In this review on the structure, the role and the potential of ceramides for skincare, we point out the necessity of rigorous process when formulating ceramides into the final product. We demonstrate the counterproductive effects of undissolved ceramides on skin barrier repair capacity of the formulas, when assessed in different in vitro models of disrupted skin barrier. Note de contenu : - CERAMIDE BIOLOGY : Ceramide structure - Ceramide classification - Ceramide biosynthesis - Composition of ceramides in the stratum corneum - CERAMIDES AND SKIN BARRIER FUNCTION : The corneocyte lipid envelope (CLE) - Organization of the lipids in the inter-corneocyte space - SKIN CONDITIONS AND CERAMIDE : Seasonal variation - Effect of ageing - Skin diseases - POTENTIAL USE OF CERAMIDES IN SKINCARE - INTRODUCTION OF CERAMIDES IN SKINCARE FORMULATIONS : Challenges in ceramide formulation - Table 1 : Classification of stratum corneum ceramides - Table 2 : Composition of unbound intercellular ceramides DOI : https://doi.org/10.1111/ics.12972 En ligne : https://drive.google.com/file/d/13BSzNNpNlUcj7iP-UfwxURZMtsAecFtw/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41352 [article]

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Boosting of retinol activity using novel lecithin : Retinol acyltransferase inhibitors / Dominik Imfeld in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 544-552 Titre : Boosting of retinol activity using novel lecithin : Retinol acyltransferase inhibitors Type de document : texte imprimé Auteurs : Dominik Imfeld, Auteur ; André Fischer, Auteur ; Leithe Budel, Auteur ; Clarissa Stoll, Auteur ; Rolf Schütz, Auteur ; Anthony Vincent Rawlings, Auteur Année de publication : 2024 Article en page(s) : p. 544-552 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Antiâge Antienzymes Collagène Collagène III Cosmétiques Etude ex vivo Lécithine La phosphatidylcholine est plus connue sous le nom lécithine. Au sens le plus strict, la lécithine désigne uniquement les phosphatidylcholines c'est-à-dire un lipide formé à partir d'une choline, d'un phosphate, d'un glycérol et de deux acides gras (figure). Dans ce contexte, il serait plus juste de parler des lécithines, car il ne s'agit pas d'une seule molécule mais d'un groupe dont la composition en acide gras varie d'une molécule à l'autre. Ainsi, les lécithines vont adopter diverses couleurs selon leur composition : du jaune, pour la lécithine végétale, au brun, pour la lécithine de poisson. Le terme de lécithine est aussi utilisé par extension pour désigner l'ensemble des phospholipides extraits du vivant (par exemple le soja), dans la mesure où ils sont majoritairement constitués de phosphatidylcholine. Peau -- Soins et hygiène Relations structure-activité Vitamine A Index. décimale : 668.5 Parfums et cosmétiques Résumé : Lecithin:retinol acyltransferase (LRAT) is the main enzyme catalysing the esterification of retinol to retinyl esters and, hence, is of central importance for retinol homeostasis. As retinol, by its metabolite retinoic acid, stimulates fibroblasts to synthesize collagen fibres and inhibits collagen-degrading enzymes, the inhibition of LRAT presents an intriguing strategy for anti-ageing ingredients by increasing the available retinol in the skin. Here, we synthesized several derivatives mimicking natural lecithin substrates as potential LRAT inhibitors. By exploring various chemical modifications of the core scaffold consisting of a central amino acid and an N-terminal acylsulfone, we explored 10 different compounds in a biochemical assay, resulting in two compounds with IC50 values of 21.1 and 32.7 μM (compounds 1 and 2), along with a simpler arginine derivative with comparative inhibitory potency. Supported by computational methods, we investigated their structure–activity relationship, resulting in the identification of several structural features associated with high inhibition of LRAT. Ultimately, we conducted an ex vivo study with human skin, demonstrating an increase of collagen III associated with a reduction of the skin ageing process. In conclusion, the reported compounds offer a promising approach to boost retinol abundance in human skin and might present a new generation of anti-ageing ingredients for cosmetic application. Note de contenu : - LRAT enzyme inhibition assay - In vitro assay - Ex vivo assay - Molecular modelling DOI : https://doi.org/10.1111/ics.12968 En ligne : https://drive.google.com/file/d/1nudejcOZvSlVima-18M-h2lWS8P6sSZ0/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41353 [article]

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The benefits and challenges of treating skin with natural oils / Roger L. McMullen in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 553-565 Titre : The benefits and challenges of treating skin with natural oils Type de document : texte imprimé Auteurs : Roger L. McMullen, Auteur Année de publication : 2024 Article en page(s) : p. 553-565 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Acides gras Barrière cutanée Cicatrisation Dermo-cosmétologie Huiles naturelles Peau -- Soins et hygiène Phytostérols Vitamine E Index. décimale : 668.5 Parfums et cosmétiques Résumé : The term natural oil refers to a fixed (non-volatile) oil of animal or plant origin. These types of oils – in contrast to essential (volatile) oils, which are obtained by steam distillation methods of plant matter – are typically obtained from plant seeds and nuts by a mechanical pressing technique or solvent extraction. The natural movement in cosmetics of the 21st century has led to renewed interest in formulating skin care products with botanical ingredients. In this article, we discuss the benefits and caveats of natural oil treatments as moisturizing agents (as occlusives and emollients) as well as their utility in wound healing and treatment of skin diseases. We also address the paradoxical behaviour of natural oils in relation to barrier function and highlight the current state of our knowledge with respect to the use of natural oils in neonatal skin care. Finally, we provide a comparison of natural oils to conventional petroleum-based oils. Note de contenu : - Composition of natural oils - Benefits of treating skin with natural oils - Bioactivity of natural oils and skin health : Essential fatty acids - Vitamin E - Phytosterols - Natural oils in wound healing - Natural oils and diseases of the skin - Therapeutic benefits of natural oils - Neonatal skin care - Paradoxical behaviour of natural oils in relation to epidermal barrier function - Performance of botanical oils versus petroleum-based oils DOI : https://doi.org/10.1111/ics.12960 En ligne : https://drive.google.com/file/d/1IC88Tn3olvxVeZpYKKi4B7UAMtVtzsc1/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41354 [article]

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Clinical efficacy of a multilamellar cream on skin physiology and microbiome in an epidermal stress model : A controlled double-blinded study (Part I) / Joachim W. Fluhr in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 566-577 Titre : Clinical efficacy of a multilamellar cream on skin physiology and microbiome in an epidermal stress model : A controlled double-blinded study (Part I) Type de document : texte imprimé Auteurs : Joachim W. Fluhr, Auteur ; Peter Menzel, Auteur ; Rolf Schwarzer, Auteur ; Dessyslava G. Nikolaeva, Auteur ; Razvigor Darlenski, Auteur ; Martin Albrecht, Auteur Année de publication : 2024 Article en page(s) : p. 566-577 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée Composés lamellaires Dermo-cosmétologie Emollients Formulation (Génie chimique) Formulation (génie chimique) -- Stabilité Microbiologie Microbiome cutané Peau -- Physiologie Peau -- Soins et hygiène pH Index. décimale : 668.5 Parfums et cosmétiques Résumé : - INTRODUCTION : Stratum corneum (SC) is essential for skin barrier function, mitigating water loss and shielding against potentially harmful substances and allergens. The SC's lipid matrix, arranged in a lamellar structure, is integral to its protective role. Our study explores the restoration effects of a multilamellar cream with an acidic pH compared to a basic placebo cream on skin physiology and its interaction with the skin microbiome after stress induction via tape stripping (TS). - MATERIALS AND METHODS : In this double-blind study, 14 healthy participants aged 21–58 years were assessed pre- and post-tape stripping, followed by a 14 days application of a multilamellar test cream and a placebo cream with evaluations on days 7, 14 and 17 for sustained effects. Skin physiology was analysed in terms of epidermal barrier function, SC hydration and surface pH. The microbiome was analysed by 16S rRNA amplicon sequencing the 16S rRNA gene using Illumina MiSeq, with subsequent species identification. - RESULTS : Our study showed significant improvements in skin barrier repair and SC hydration with verum, particularly after 14 days of application, while both creams initially enhanced stratum corneum hydration. No significant changes in surface-pH were detected. The skin microbiome analysis revealed that TS slightly decreased alpha diversity, a trend that verum significantly reversed, enhancing diversity beyond baseline levels after 14 days. Overall, while both creams contributed to a broader microbial phyla diversity over time, no significant changes in the abundance of specific genera or species were noted between treatments. - DISCUSSION AND CONCLUSION : Our study delineates the efficacy of a pH-optimized multilamellar cream in enhancing epidermal barrier recovery and SC hydration post-sequential TS, in contrast to an unstructured basic placebo. Verum cream significantly improved skin barrier function and SC hydration at day 14, with sustained effects evident beyond the treatment period. Furthermore, the multilamellar formulation facilitated the restitution of cutaneous microbiome diversity, a key indicator of healthy skin ecology, underscoring the symbiotic relationship between barrier integrity and microbial composition. These findings underscore the importance of multilamellar emollient structures in dermatological therapeutics, with potential implications for the design of advanced skincare interventions that holistically support cutaneous resilience and homeostasis. Note de contenu : - MATERIALS AND METHODS : Study approval and participants - Study design - Skin physiology parameters - Test formulations - Microbiome assessment - Sequence analysis - Statistical analysis - RESULTS : Participant characterization and measuring conditions - Skin physiology - Microbiome DOI : https://doi.org/10.1111/ics.12950 En ligne : https://drive.google.com/file/d/1U0a6kkQUzXUuQE9keMO6rSFr2mHLmLK5/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41355 [article]

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Impact of multilamellar formulations on stratum corneum lipid organization and epidermal lipid barrier enhancement (Part II) / Joachim W. Fluhr in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 578-589 Titre : Impact of multilamellar formulations on stratum corneum lipid organization and epidermal lipid barrier enhancement (Part II) Type de document : texte imprimé Auteurs : Joachim W. Fluhr, Auteur ; Razvigor Darlenski, Auteur ; Stephan Daehnhardt-Pfeiffer, Auteur ; Martin Albrecht, Auteur Année de publication : 2024 Article en page(s) : p. 578-589 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée Composés lamellaires Cosmétiques Dermo-cosmétologie Emollients Lécithine La phosphatidylcholine est plus connue sous le nom lécithine. Au sens le plus strict, la lécithine désigne uniquement les phosphatidylcholines c'est-à-dire un lipide formé à partir d'une choline, d'un phosphate, d'un glycérol et de deux acides gras (figure). Dans ce contexte, il serait plus juste de parler des lécithines, car il ne s'agit pas d'une seule molécule mais d'un groupe dont la composition en acide gras varie d'une molécule à l'autre. Ainsi, les lécithines vont adopter diverses couleurs selon leur composition : du jaune, pour la lécithine végétale, au brun, pour la lécithine de poisson. Le terme de lécithine est aussi utilisé par extension pour désigner l'ensemble des phospholipides extraits du vivant (par exemple le soja), dans la mesure où ils sont majoritairement constitués de phosphatidylcholine. Microscopie électronique en transmission Peau -- Soins et hygiène pH Index. décimale : 668.5 Parfums et cosmétiques Résumé : - INTRODUCTION : The integrity of the stratum corneum (SC) is crucial for the skin's barrier function, protecting against environmental stressors and minimizing transepidermal water loss. Advances in skincare formulations have introduced multilamellar systems designed to emulate the SC's lipid composition and organization. This study hypothesizes that the application of a multilamellar cream will significantly impact the SC's lipid content and lamellar structure, thereby enhancing the epidermal barrier. - METHODS : A saturated phosphatidylcholine-based multilamellar cream was applied to a cohort of adult subjects with very dry skin. Electron microscopy was utilized to analyse the micro-morphology of the cream and its integration into the lipid-depleted SC. Lipid analysis was conducted to quantify changes in the intercellular lipid matrix. - RESULTS : Transmission-electron microscopy (TEM) imaging demonstrated that the multilamellar cream possesses a structured arrangement comparable to the natural SC architecture. Short-term application revealed a time-dependent restoration of lipid bilayers, while a 14-day regimen showed a marked increase in lipid lamellae density and length within the SC. Lipid analysis indicated a significant increase in total lipid content, with notable enhancements in ceramide and free fatty acid levels, without altering cholesterol levels. Lipid ratio analysis further confirmed the rebalancing of the SC's lipid composition. - DISCUSSION : The multilamellar cream selectively increased specific lipids critical for barrier function, suggesting an action mechanism that aligns with the skin's natural regulatory processes. This selective augmentation indicates the potential of the formulation to not only restore but also enhance the epidermal barrier, with the maintenance of physiological lipid ratios suggesting compatibility with intrinsic repair mechanisms. - CONCLUSION : The study confirms that a multilamellar cream can significantly improve the SC's lipid composition and structural integrity, indicating enhanced barrier function. They are pivotal for skincare professionals, dermatologists, and product developers, enriching the understanding of multilamellar creams' benefits and applications in improving epidermal barrier function. Note de contenu : - MATERIALS AND METHODS : Cream formulation - Ultrastructure analysis of cream vehicle - Ultrastructure analysis of treated skin - Lipid analysis by HPTLC - Study population - Statistics - RESULTS : Lipid morphology of the multilamellar formulation - Enhanced lipid bilayers in vivo by short-term application - Enhanced lipid bilayers in vivo in a 14-day application - Improved composition of critical barrier lipids in vivo in a 14-day application DOI : https://doi.org/10.1111/ics.12971 En ligne : https://drive.google.com/file/d/1e6txw5orQ1eu7htXGVIdPivCYwQt5sbh/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41356 [article]

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Protein degradation in the stratum corneum / Georgios N. Stamatas in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 590-597 Titre : Protein degradation in the stratum corneum Type de document : texte imprimé Auteurs : Georgios N. Stamatas, Auteur Année de publication : 2024 Article en page(s) : p. 590-597 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée Cosmétiques Couche cornée Dermo-cosmétologie Détérioration enzymatique Formulation (Génie chimique) Peau -- Physiologie Peau -- Soins et hygiène Protéines -- Détérioration Index. décimale : 668.5 Parfums et cosmétiques Résumé : The stratum corneum (SC), the outermost epidermal layer, plays a pivotal role in skin barrier function. This review delves into the intricate process of protein degradation within the stratum corneum, elucidating the roles of specific enzymes, regulatory mechanisms and the consequent impact on various skin conditions. Protein degradation is a finely tuned process, orchestrated by a suite of proteolytic enzymes like kallikreins. These enzymes are responsible for the breakdown of corneodesmosomes and the orderly desquamation of corneocytes, a process essential for skin homeostasis. Another critical enzymatic process is the breakdown of proteins like filaggrin and the generation of amino acids and their derivatives, required in the physiological water-handling properties of the SC. Regulation of these proteolytic activities is complex, involving a balance between endogenous inhibitors and other factors like pH, hydration and environmental stressors. Dysregulation of protease activity is linked to a spectrum of skin conditions, ranging from xerosis to inflammatory diseases like atopic dermatitis and psoriasis. Aberrant protein degradation can lead to compromised skin barrier function, increased tissue water loss and heightened susceptibility to infections and allergens. Understanding the factors affecting protein degradation can inform the development of targeted skincare products. Advances in biochemistry and dermatology have paved the way for the search for active ingredients designed to modulate protease activity. Such innovations may offer promising therapeutic avenues for enhancing skin barrier function and treating skin disorders. This review underscores the significance of enzymatic protein degradation in the SC and its regulatory mechanisms. It provides insights into the pathophysiology of skin diseases and outlines the potential for novel skincare interventions. By bridging the gap between fundamental research and practical applications, this article aims to inspire further investigation for better understanding of skin physiology and innovation in the realm of skincare product development. Note de contenu : - SC cohesion and desquamation - Proteolytic skin desquamation - Regulation of proteolytic desquamation - Proteolytic degradation of flg-like proteins - Pathologies related to dysregulation of protease activity in the SC - Implications for skincare product development DOI : https://doi.org/10.1111/ics.12974 En ligne : https://drive.google.com/file/d/1hyEOYxQVEUFz6dRXC9p-XtJU6sWBfK1Q/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41357 [article]

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A practical clinical device for evaluating changes to the skin's sebum from ozone / Frank Liebel in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 598-602 Titre : A practical clinical device for evaluating changes to the skin's sebum from ozone Type de document : texte imprimé Auteurs : Frank Liebel, Auteur ; Stephanie Petersen, Auteur ; Gary Grove, Auteur ; Tim Houser, Auteur Année de publication : 2024 Article en page(s) : p. 598-602 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cosmétiques Dermo-cosmétologie Ozone Peau -- analyse Peau -- Effets de la pollution atmosphérique Peau -- Soins et hygiène Sébum Squalène Index. décimale : 668.5 Parfums et cosmétiques Résumé : - BACKGROUND : It is known that tropospheric ozone (O3) generated from pollutants reacting with UV forms lipid peroxidation products and induces oxidative stress to the skin. With the ever-increasing consumer awareness of the effects pollution has on skin, more testing methods will be needed to evaluate cosmetic ingredients. Recently, others have shown how antioxidants are able to reduce the effects from ozone on skin through in vitro, ex vivo and clinical studies where human subjects place their arms into large stationary chambers. - OBJECTIVE : To develop a small, easy to use ozone exposure module (OEM) that can be used on various sites of the body and to validate this device for use in testing the ability of topical products to mitigate the effects of ozone exposure on the skin. - MATERIALS AND METHODS : We have produced an OEM which can generate levels of ozone in excess of 1000 ppb and can be set to achieve the equivalent exposure to what is found in polluted environmental conditions. After exposure we used D-squame discs to remove the sebum and analytically quantitate squalene depletion. Squalene, which is very sensitive to ROS, easily oxidizes into early metabolite squalene monohydroperoxide (SQOOH) with ozone exposure. - RESULTS : We were able to show decreases in squalene levels after exposure and protective effects from a topical formulation. - CONCLUSION : This generator will be a useful tool for researchers to easily create a small and safe exposure from ozone for clinical testing. Note de contenu : - MATERIALS AND METHODS : Device specifics - In vivo studies - Analytical method for squalene detection from D-Squame tapes - Data analysis - RESULTS AND DISCUSSION : Results - Discussion DOI : https://doi.org/10.1111/ics.12998 En ligne : https://drive.google.com/file/d/1gmXdZ-4YIa3jjn8qbqyWq6SnU25v6W_A/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41358 [article]

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In vivo confocal Raman spectroscopy : The window into the skin / J. M. Crowther in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 603-609 Titre : In vivo confocal Raman spectroscopy : The window into the skin Type de document : texte imprimé Auteurs : J. M. Crowther, Auteur ; P. J. Matts, Auteur Année de publication : 2024 Article en page(s) : p. 603-609 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Dermatologie Etude in vivo Formulation (Génie chimique) Peau -- analyse Spectroscopie Raman Index. décimale : 668.5 Parfums et cosmétiques Résumé : Development of in vivo confocal Raman spectroscopy (ICRS) methodology over the last 20 years has enabled previously unavailable capability to acquire molecular concentration gradients across the stratum corneum (SC), at the micron level and in a clinical setting. Professor Tony Rawlings has been a driving force in SC research for over 30 years, working with a wide range of teams across the world. Because a detailed knowledge of skin biochemistry was key to interpreting ICRS-acquired molecular concentration gradients, the authors formed a close working relationship with Professor Rawlings during the development of ICRS. This article, therefore, presents a summary of this process and how challenges raised by application of ICRS were tackled, towards the goal of validating the technique for clinical skin measurement. Note de contenu : - How it all began - The validation process DOI : https://doi.org/10.1111/ics.12989 En ligne : https://drive.google.com/file/d/1hfPW97lhPUDazOHKQwPDoHGWJkm4f6rL/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41359 [article]

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What defines dry skin ? Correlating a range of skin hydration parameters with In Vivo Confocal Raman Spectroscopy / Jonathan M. Crowther in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 610-622 Titre : What defines dry skin ? Correlating a range of skin hydration parameters with In Vivo Confocal Raman Spectroscopy Type de document : texte imprimé Auteurs : Jonathan M. Crowther, Auteur ; Paul J. Matts, Auteur Année de publication : 2024 Article en page(s) : p. 610-622 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée Biotechnologie Chimie analytique Dermo-cosmétologie Hydratation Justification de l'allégation Peau -- analyse Sécheresse cutanée Une xérose est un dessèchement de la peau. Elle peut avoir différentes causes, comme certaines pathologies (dermatite atopique aussi appelé eczéma atopique), des carences, notamment en Vitamine A, ou des facteurs externes, comme les contacts avec des substances irritantes ou le traitement par certains médicaments. Spectroscopie Raman Index. décimale : 668.5 Parfums et cosmétiques Résumé : - OBJECTIVE : While there are a wide range of approaches for the assessment of skin hydration, it is not always clear how data from them relate to one another or to the skin itself. With the development of in vivo Confocal Raman Spectroscopy (ICRS), it has become possible to measure water concentration as a function of protein/depth within the stratum corneum (SC). This article reports a comparison between electrical skin hydration measures/visual/optical grading and water concentration profiles measured using ICRS, to better understand the relationship between these approaches. - METHODS : SC hydration of lower-leg skin with varying degrees of dryness was assessed using visual grading (live and from digital images), Corneometer®, Visioscan and ICRS. In addition, a custom fingerprint sensor was used to image surface capacitance (as a surrogate of SC hydration), and SC barrier function was assessed using evaporimetry (to measure trans-epidermal water loss; TEWL). - RESULTS : Significant correlations were observed between a number of different skin grading/measurement approaches and ICRS data. ICRS hydration profiles also revealed a region near the SC surface with a relatively flat water profile in dry skin subjects. - CONCLUSIONS : The advent of quantitative in vivo analytical techniques such as ICRS, which can be used in a clinical setting, has enabled greater insight into more conventional approaches for assessing skin dryness. While traditional skin grading and biophysical methods for measuring skin hydration have varying degrees of correlation with one another, they also provide comparatively unique information about different regions within the SC. This should enable a more informed approach to product development in the future. Note de contenu : - Study methodology outline - Assessment techniques DOI : https://doi.org/10.1111/ics.12990 En ligne : https://drive.google.com/file/d/1KZfVR8M_zlfwcdjlgcCcXqBxEyHQNYNk/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41360 [article]

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The importance of stratum corneum w-linoleoyloxyacylceramides in human skin barrier health : their biochemistry, processing enzymes and metabolites involved in corneocyte lipid envelope maturation / Anthony Vincent Rawlings in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 46, N° 4 (08/2024)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 46, N° 4 (08/2024) . - p. 623-642 Titre : The importance of stratum corneum w-linoleoyloxyacylceramides in human skin barrier health : their biochemistry, processing enzymes and metabolites involved in corneocyte lipid envelope maturation Type de document : texte imprimé Auteurs : Anthony Vincent Rawlings, Auteur ; Majella E. Lane, Auteur ; Rainer Voegeli, Auteur Année de publication : 2024 Article en page(s) : p. 623-642 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Barrière cutanée Biochimie Céramides Un céramide est un sphingolipide résultant de la combinaison d'un acide gras avec la sphingosine via une liaison amide. On trouve de telles molécules en abondance dans les membranes cellulaires, où elles entrent notamment dans la constitution des sphingomyélines. Les céramides ne jouent pas qu'un rôle structurel dans les membranes biologiques, et peuvent également revêtir des fonctions de signalisation lipidique. Leurs actions les mieux comprises vont de la différenciation cellulaire à la mort cellulaire programmée (apoptose) en passant par la prolifération cellulaire. Les acides gras qui les constituent ont généralement un nombre pair (de 16 à 24) d'atomes de carbone, sont saturés ou monoinsaturés, et sont souvent α-hydroxylés. La plupart des céramides n'existent pas à l'état naturel si ce n'est comme précurseurs de la biosynthèse des sphingolipides par une réaction d'addition sur la fonction alcool primaire de la sphingosine. (Wikipedia) Cornéocytes Couche cornée Dermatologie Enzymes Une enzyme est une protéine dotée de propriétés catalytiques. Pratiquement toutes les biomolécules capables de catalyser des réactions chimiques dans les cellules sont des enzymes ; certaines biomolécules catalytiques sont cependant constituées d'ARN et sont donc distinctes des enzymes : ce sont les ribozymes. Une enzyme agit en abaissant l'énergie d'activation d'une réaction chimique, ce qui accroît la vitesse de réaction. L'enzyme n'est pas modifiée au cours de la réaction. Les molécules initiales sont les substrats de l'enzyme, et les molécules formées à partir de ces substrats sont les produits de la réaction. Presque tous les processus métaboliques de la cellule ont besoin d'enzymes pour se dérouler à une vitesse suffisante pour maintenir la vie. Les enzymes catalysent plus de 5 000 réactions chimiques différentes2. L'ensemble des enzymes d'une cellule détermine les voies métaboliques qui peuvent avoir lieu dans cette cellule. L'étude des enzymes est appelée enzymologie. Les enzymes permettent à des réactions de se produire des millions de fois plus vite qu'en leur absence. Un exemple extrême est l'orotidine-5'-phosphate décarboxylase, qui catalyse en quelques millisecondes une réaction qui prendrait, en son absence, plusieurs millions d'années3,4. Comme tous les catalyseurs, les enzymes ne sont pas modifiées au cours des réactions qu'elles catalysent, et ne modifient pas l'équilibre chimique entre substrats et produits. Les enzymes diffèrent en revanche de la plupart des autres types de catalyseurs par leur très grande spécificité. Cette spécificité découle de leur structure tridimensionnelle. De plus, l'activité d'une enzyme est modulée par diverses autres molécules : un inhibiteur enzymatique est une molécule qui ralentit l'activité d'une enzyme, tandis qu'un activateur de cette enzyme l'accélère ; de nombreux médicaments et poisons sont des inhibiteurs enzymatiques. Par ailleurs, l'activité d'une enzyme décroît rapidement en dehors de sa température et de son pH optimums. Membrane cellulaire Métabolites Index. décimale : 668.5 Parfums et cosmétiques Résumé : Over the past 50 years there have been great strides made in the discovery of the composition and relevance of the total stratum corneum (SC) ceramide matrix. However, the focus of this review is on the free intercellular class of ω-linoleoyloxyacylceramides, corneocyte-bound ceramides and associated lipids known as the corneocyte lipid envelope (CLE) together with their processing enzymes involved in aiding ceramide attachment the corneocyte protein envelope (CPE). Two structural models and partially shared biosynthetic pathways have been proposed for the attachment of CPE-bound O-ceramides (ω-hydroxyceramides attached to glutamate residues of proteins in the (CPE) using the 12R-lipoxygenase (12R-LOX)/epidermal lipoxygenase-3 (eLOX3)/epoxide hydrolase-3 (EPHX3)/unknown esterase/ transglutaminase-1 (TG1) attachment pathway) and CPE-bound EO-ceramides (epoxy-enone ceramides attached to cysteine residues of proteins in the CPE using the 12R-LOX/eLOX3/short chain dehydrogenase/reductase family 9C member 7 (SDR9C7)/non-enzymatic attachment pathway), i.e. there is a bifurcation step beyond epidermal eLOX3. Their formation and structures will be discussed as well as their relevance in compromised skin barrier conditions together with our own work on SC maturation examined by proteomics, lipidomics, enzyme immunolocalization studies, mechanical fragility assays and Nile red staining of corneocyte envelopes (CE). Reduced levels of 12R-LOX, eLOX3, SDR9C7 and TG1 were observed in photodamaged skin of the cheeks that were associated with reduced SC maturation as evidenced by Nile red staining and increased CE fragility. In the severely photodamaged cheeks of Albino African SC we also observed increased levels of acylceramides. Concomitantly by reducing the activity of 12R-LOX by antibody inhibition and TG1 inhibition with a known chemical inhibitor, we demonstrated in a humidity-based ex vivo SC maturation model that these enzymes contributed to increased CE hydrophobicity and mechanical integrity. We hypothesize that at least the CPE-bound O-ceramide pathway is operational in the SC. Nevertheless, our understanding of the full complexity of ω-linoleoyloxyacylceramides and the composition of the CLE is limited particularly on cosmetically relevant body sites such as the face. Note de contenu : - Early studies on covalently bound ceramides and related w-linoleoyloxyacylceramides - Visualization of the corneocyte lipid envelope - Early research on the CPE ceramidation mechanism - (patho)physiology of w-linoleoyloxyacylceramides and associated CPE-bound species - w-linoleoyloxyacylceramide processing enzymes and identification of CPE-bound eo ceramides - Metabolism of w-linoleoyloxyacylceramides in human SC - Nile red staining, the CLE and relation to our own research DOI : https://doi.org/10.1111/ics.12955 En ligne : https://drive.google.com/file/d/1uwo_TXbQK3zlb-WEkiteqTAYuUFst8xN/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=41361 [article]

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