title: Multiscale Approach to Characterize Mechanical Properties of Tissue Engineered Skin.
abstract: Tissue engineered skin usually consist of a multi-layered visco-elastic material composed of a fibrillar matrix and cells. The complete mechanical characterization of these tissues has not yet been accomplished. The purpose of this study was to develop a multiscale approach to perform this characterization in order to link the development process of a cultured skin to the mechanical properties. As a proof-of-concept, tissue engineered skin samples were characterized at different stages of manufacturing (acellular matrix, reconstructed dermis and reconstructed skin) for two different aging models (using cells from an 18- and a 61-year-old man). To assess structural variations, bi-photonic confocal microscopy was used. To characterize mechanical properties at a macroscopic scale, a light-load micro-mechanical device that performs indentation and relaxation tests was designed. Finally, images of the internal network of the samples under stretching were acquired by combining confocal microscopy with a tensile device. Mechanical properties at microscopic scale were assessed. Results revealed that adding cells during manufacturing induced structural changes, which provided higher elastic modulus and viscosity. Moreover, senescence models exhibited lower elastic modulus and viscosity. This multiscale approach was efficient to characterize and compare skin equivalent samples and permitted the first experimental assessment of the Poisson's ratio for such tissues.
authors.affiliation: Laboratoire de Tribologie et Dynamique des Systèmes (LTDS, CNRS UMR5513), Université de Lyon, Ecole Centrale de Lyon, ENISE, 69134, Ecully, France.
authors.forename: S
authors.identifier: 0000-0003-0982-8210
authors.initials: S
authors.lastname: Tupin
authors.affiliation: Ecole Nationale Supérieure des Mines, CIS-EMSE, INSERM UMR1059, SAINBIOSE, 42023, Saint-Etienne, France.
authors.forename: J
authors.initials: J
authors.lastname: Molimard
authors.affiliation: BASF Beauty Care Solutions France S.A.S, 69366, Lyon Cedex 07, France.
authors.forename: V
authors.initials: V
authors.lastname: Cenizo
authors.affiliation: Laboratoire de Tribologie et Dynamique des Systèmes (LTDS, CNRS UMR5513), Université de Lyon, Ecole Centrale de Lyon, ENISE, 69134, Ecully, France.
authors.forename: T
authors.initials: T
authors.lastname: Hoc
authors.affiliation: BASF Beauty Care Solutions France S.A.S, 69366, Lyon Cedex 07, France.
authors.forename: B
authors.initials: B
authors.lastname: Sohm
authors.affiliation: Laboratoire de Tribologie et Dynamique des Systèmes (LTDS, CNRS UMR5513), Université de Lyon, Ecole Centrale de Lyon, ENISE, 69134, Ecully, France. hassan.zahouani@ec-lyon.fr.
authors.forename: H
authors.initials: H
authors.lastname: Zahouani
mesh_terms: D000293:Adolescent; D006801:Humans; D008297:Male; D008875:Middle Aged; D033081:Shear Strength; D017768:Skin, Artificial; D013314:Stress, Mechanical; D013718:Tensile Strength; D023822:Tissue Engineering
keywords: Bi-photonic confocal microscopy; Digital image correlation; Indentation; Opto-mechanical system; Poisson’s ratio; Reconstructed skin