Skin barrier function in infants - new challenges and new opportunities

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1 Skin barrier function in infants - new challenges and new opportunities Georgios N Stamatas, Ph.D. Research Associate Director and Fellow Johnson & Johnson Santé Beauté France Any third party trademarks that may be used herein are the trademarks of their respective owners.

2 Question Asked circa 2 What can we find out about healthy infant skin by studying it in vivo with new non-invasive tools 2

3 State of knowledge then At birth, infant skin undergoes a dramatic transition from an aqueous to a dry terrestrial environment but if left on its own after a few short weeks, the skin barrier is fully established (equivalent to adult barrier). ph Postnatal Age (Days) Visscher M, et al. Pediatr Dermatol. 2;17:45-51 Mauro T, Behne M. In: Neonatal Skin: Structure and Function. 23:

4 State of knowledge and now (punchline) Compared With Adult Skin, Baby Skin Structure, Composition, and Function Are Different and Continue to Develop After Birth 4

5 Enablers (a.k.a. non-invasive methods) Traditional Electrical properties ~ SC hydration TEWL ~ SC water barrier function ph electrode ~ skin surface acidity 5

6 Enablers (a.k.a. non-invasive methods) More modern Optical methods Spectroscopy Imaging Microscopy Reflectance Infra Red Raman Visible Fluorescence Video Confocal Stamatas GN in Textbook of Aging, Chapter 69, 21;

7 Function Skin Barrier Maturation Better Barrier Barrier Integrity TEWL (g/m 2 /hr) Infant Adult Water absorption-desorption Skin Hydration Conductance (NOVA DPM a.u.) Better Hydration Nikolovski J et al. Journal of Investigative Dermatology 28:128;

8 Function Higher cell turnover rates Fluorescence (a.u.) Normalized tryptophan fluorescence Wavelength (nm) Infant years Stamatas, GN et al. Pediatric Dermatology 21: 27(2), In vivo Fluorescence Spectroscopy Skin Native Fluorophores: tyrosine, tryptophan, collagen x-links, elastin x-links Normalized tryptophan fluorescence Adult years 8

9 Structure Denser Glyphics, smaller Cells, thinner Layers Epiluminescence Microscopy ADULT INFANT 5 µm Stamatas, GN et al. Pediatric Dermatology 21: 27(2), Stratum Corneum Thickness (mm) Epidermis Thickness (mm) Infant 7.3 ± ± 3.4 Adult 1.5 ± ± 5.2 9

10 Composition Less aminoacids, more lactate NMF CONCENTRATION (MASS %) INFANT * * * ADULT * * * * DEPTH (MICRONS) Outside Stratum Corneum Epidermis Nikolovski J et al. Journal of Investigative Dermatology 28:128; Stamatas GN et al. presented at the World Congress of Dermatology, Seoul, S. Korea, May 211 1

11 In Summary...so far Infant Skin Undergoes a Maturation Process Structure Composition Function Stratum Corneum and Epidermal thickness Corneocyte size Surface Roughness Collagen in the dermis Elasticity Water content Natural Moisturizing Factor (NMF) Melanin Lipid content and organization Water Handling Properties Barrier Function Skin Reactivity Cell Proliferation 11

12 Microbiome Infant Phylum Percentages Adult Phylum Percentages 19% 9% 2% 51% Firmicutes Actinobacteria Bacteroidetes Proteobacteria 19% Other Average % Incidence On Skin Age Group (months) Capone K et al. J Invest Dermatol 211; 131: Gao, et al. Proc Natl Acad Sci. 27;14: OTHER Achromobacter Chryseobacterium Moraxella Granulicatella Roseburia Diaphorobacter Faecalibacterium 12

13 Topology.25 Cell Density.2 SS.15.1 SG yr 2 yr 3 yr adult Delauney NN Distance SG SS MST Segment Length SG SS 45% 4% 35% 3% 25% 2% 15% 1% 5% NN Frequency 2yrs 3yrs Adult 1yr 2yr 3yr Adult 1yr 2yr 3yr Adult Stamatas GN et al. Presented at the European Academy of Dermatology and Venereology, Spring meeting, 214 %

14 Water Mobility 6 Stratum Corneum Stratum Granulosum % Fraction of total water Intermediate Most Mobile Least Mobile (Bound) O H Intermediate Bound Depth (/SC thickness) H O H H Most Mobile Boireau-Adamezyk et al. Journal of Investigative Dermatology 214:134;

15 Modeling (Part 1: Structure) Baby skin (simulation) Adult skin (simulation) Suetterlin et al. Bioinformatics, 29:25(16);

16 Modeling (Part 2: Function) Van Logtestijn et al. presented at Skin Forum meeting

17 The Future: new tools new insights OMICS Higher Order Microscopy AFM-FTIR Fluorescence Lifetime etc. 17

18 Acknowledgements Kamlesh Bhagat Lin Ma Niels Grabe Thomas Suetterlin Erika Tsingos Reiko Tanaka Mark van Longtestijn Martial Guillaud Gaeme Kirkpatrick Zhao Yang Chen Annie Li Arlette Baillet-Guffroy Our volunteers Janet Nikolovski Ben Wiegand Nik Kollias Lorena Telofski Eduardo Ruvolo Melissa Chu Michael Luetke Katharine Martin Catherine Mack Correa Neena Tierney Kim Capone Jalil Bensaci Elise Boireau 18