title: Morpho-elasticity of inflammatory fibrosis: the case of capsular contracture.
abstract: Inflammatory fibrosis is a wound-healing reaction of the immune system in mammals against aggression. After a signalling cascade, fibroblasts and potentially myofibroblasts make a stiff collagenous tissue inside the body that modifies the original healthy tissue. We focus here on the implant-induced fibrosis that aims to encapsulate the implant with a typical fibrous tissue called the capsule. Focusing on breast capsules, we aim to understand the mechanical properties of these tissues, to test the validity of fibre models that have been established in other contexts such as arteries. For this purpose, we perform force-extension experiments and show that mechanical constitutive laws of these tissues are especially difficult to derive, because models are sensitive to fibre orientation and dispersion, independently of the variation between individuals. In addition, fibre breakdown, and possibly remodelling, occur during the extension experiments. However, the high stiffness of the capsular tissue, compared with the healthy tissue, added to the fact that an inflammatory process has no reason to cease, is at the origin of large compressive stresses in vivo, which explains the pain and unaesthetic deformity. We evaluate the stresses responsible for the pain and the buckling instability, which have no reason to stop if the inflammation persists.
authors.affiliation: Laboratoire de Physique Statistique, Ecole Normale Supérieure, UPMC Univ Paris 06, Université Paris Diderot, CNRS, 24 rue Lhomond, 75005 Paris, France Institut Universitaire de Cancérologie, Faculté de médecine, Université Pierre et Marie Curie-Paris 6, 91 Bd de l'Hôpital, 75013 Paris, France benamar@lps.ens.fr.
authors.forename: Martine
authors.initials: M
authors.lastname: Ben Amar
authors.affiliation: Laboratoire de Physique Statistique, Ecole Normale Supérieure, UPMC Univ Paris 06, Université Paris Diderot, CNRS, 24 rue Lhomond, 75005 Paris, France Institut Universitaire de Cancérologie, Faculté de médecine, Université Pierre et Marie Curie-Paris 6, 91 Bd de l'Hôpital, 75013 Paris, France.
authors.forename: Min
authors.initials: M
authors.lastname: Wu
authors.affiliation: Laboratoire de Physique et Mécanique des Milieux Hétérogènes (PMMH), UMR CNRS 7636; PSL - ESPCI, 10 rue Vauquelin, 75005 Paris, France.
authors.forename: Miguel
authors.initials: M
authors.lastname: Trejo
authors.affiliation: Hopital Tenon APHP, Université Pierre et Marie Curie-Paris 6, 3 rue de la Chine, 75020 Paris, France.
authors.forename: Michael
authors.initials: M
authors.lastname: Atlan
mesh_terms: D000818:Animals; D001706:Biopsy; D001940:Breast / Q000473:pathology; D003094:Collagen / Q000737:chemistry; D003286:Contracture; D004548:Elasticity; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D005355:Fibrosis / Q000276:immunology* / Q000473:pathology*; D005549:Foreign-Body Reaction / Q000473:pathology; D006801:Humans; D007249:Inflammation; D008954:Models, Biological; D058628:Myofibroblasts / Q000473:pathology*; D010586:Phagocytes; D015398:Signal Transduction; D014945:Wound Healing
chemical_list: D003094:Collagen
keywords: fibrosis; inflammation; nonlinear elasticity; pathology; patient biopsy; soft tissues