A minimally invasive clinical model to test sunscreen toxicity based on oxidative stress levels using microbiopsy and confocal microscopy - a proof of concept study / Miko Yamada in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 42, N° 5 (10/2021)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 42, N° 5 (10/2021) . - p. 462-470 Titre : A minimally invasive clinical model to test sunscreen toxicity based on oxidative stress levels using microbiopsy and confocal microscopy - a proof of concept study Type de document : document électronique Auteurs : Miko Yamada, Auteur ; Lynlee L. Lin, Auteur ; Lydia Y. T. Hang, Auteur ; Paul J. Belt, Auteur ; H. Peter Soyer, Auteur ; Anthony P. Raphael, Auteur ; Tarl W. Prow, Auteur Année de publication : 2020 Article en page(s) : p. 462-470 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cosmétiques -- Toxicologie Dermo-cosmétologie Etude in vivo Imagerie (technique) Microscopie confocale Nanoparticules Oxyde de zinc Peau -- Biopsie Produits antisolaires Index. décimale : 668.5 Parfums et cosmétiques Résumé : - Objective : This proof‐of‐concept study demonstrated that using minimally invasive skin microsampling could enable significantly higher throughput of cosmetic testing in volunteers than conventional biopsy. Nanoparticle sunscreen was used as a model to test toxicity based on oxidative stress using microbiopsy and confocal imaging. - Methods : Six volunteers were recruited for this study (3 males and 3 females). Zinc oxide nanoparticle containing topical formulation was prepared at 10% w/v. Each volunteer had 3 areas of 4 cm2 each mapped on each inner forearm for a total of 6 treatment areas (intact/ tape-stripped and with/without treatment). The topical zinc-nanoparticle formulation was applied directly to volunteer skin (2mg/cm2) for 2 hrs. Microbiopsied tissue from each treatment group was stained for reactive oxygen and nitrogen species in addition to mitochondrial superoxide. The stained samples were then imaged using confocal microscopy prior to image analysis. - Results : Skin exposed to zinc oxide nanoparticles did not show any significant increases in oxidative stress. Zinc oxide nanoparticle tape-stripped skin resulted in signal significantly lower (P < 0.001) oxidative stress levels than t-butylated hydroxytoluene treated tape-stripped skin for oxidative stress markers. Topically applied zinc oxide nanoparticles had no detectable effect on the oxidative status in volunteer skin. No adverse reactions or effects were observed after all treatments including microbiopsy. - Conclusion : The data support the hypothesis that microbiopsy is a viable approach to study cosmeceutical- skin interactions in volunteers with capacity for molecular assays and high throughput with very low risk to the volunteer. Note de contenu : - Subjects - Tape-stripping and trans-epidermal water loss (TEWL) - Zinc oxide nanoparticle (ZnO-NP) preparation and administration - Microbiopsy - Reactive Oxygen and Nitrogen Species (CellROX) and Mitochondrial Superoxide (MitoSOX) Assessment - Confocal laser microscopy - Data analysis - Table : Treatment groups as per 4 cm2 area marked out on the arm. Separation of arms A and B for the two solutions (ZnO-NP sunscreen and CCT) minimized cross-contamination DOI : https://doi.org/10.1111/ics.12646 En ligne : https://drive.google.com/file/d/1AmsQAEOqV5ZhvAvSeVP8jkxFCki-1KE2/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35411 [article]

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Towards data-driven quantification of skin ageing using reflectance confocal microscopy / Samuel C. Hames in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 43, N° 4 (08/2021)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 43, N° 4 (08/2021) . - p. 466-473 Titre : Towards data-driven quantification of skin ageing using reflectance confocal microscopy Type de document : document électronique Auteurs : Samuel C. Hames, Auteur ; Andrew P. Bradley, Auteur ; Marco Ardigo, Auteur ; H. Peter Soyer, Auteur ; Tarl W. Prow, Auteur Année de publication : 2021 Article en page(s) : p. 466-473 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse d'image L'analyse d'image est la reconnaissance des éléments contenus dans l'image. Il ne faut pas confondre analyse (décomposition en éléments) et traitement (action sur les composantes) de l'image. Dermatologie Evaluation Microscopie confocale Photovieillissement (dermatologie) Vieillissement cutané Index. décimale : 668.5 Parfums et cosmétiques Résumé : Introduction : Evaluation of skin ageing is a non-standardized, subjective process, with typical measures relying coarse, qualitatively defined features. Reflectance confocal microscopy depth stacks contain indicators of both chrono-ageing and photo-ageing. We hypothesize that an ageing scale could be constructed using machine learning and image analysis, creating a data-driven quantification of skin ageing without human assessment. Methods : En-face sections of reflectance confocal microscopy depth stacks from the dorsal and volar forearm of 74 participants (36/18/20 training/testing/validation) were represented using a histogram of visual features learned using unsupervised clustering of small image patches. A logistic regression classifier was trained on these histograms to differentiate between stacks from 20- to 30-year-old and 50- to 70-year-old volunteers. The probabilistic output of the logistic regression was used as the fine-grained ageing score for that stack in the testing set ranging from 0 to 1. Evaluation was performed in two ways: on the test set, the AUC was collected for the binary classification problem as well as by statistical comparison of the scores for age and body site groups. Final validation was performed by assessing the accuracy of the ageing score measurement on 20 depth stacks not used for training or evaluating the classifier. Results : The classifier effectively differentiated stacks from age groups with a test set AUC of 0.908. Mean scores were significantly different when comparing age groups (mean 0.70 vs. 0.44; t = −6.62, p = 0.0000) and also when comparing stacks from dorsal and volar body sites (mean 0.64 vs. 0.53; t = 3.12, p = 0.0062). On the final validation set, 17 out of 20 depth stacks were correctly labelled. Discussion : Despite being limited to only coarse training information in the form of example stacks from two age groups, the trained classifier was still able to effectively discriminate between younger skin and older skin. Curiously, despite being only trained with chronological age, there was still evidence for measurable differences in age scores due to sun exposure—with marked differences in scores on sun-exposed dorsal sites of some volunteers compared with less sun-exposed volar sites. These results suggest that fine-grained data-driven quantification of skin ageing is achievable. Note de contenu : - Data collections - Image representation and skin ageing classifier training - Test set evaluation - Final validation DOI : https://doi.org/10.1111/ics.12720 En ligne : https://drive.google.com/file/d/1HGwYSakgC3DrgHndSDLELxXAApUVrVHL/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=36682 [article]

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