Biomech Model Mechanobiol (2015) 14:357–370 DOI 10.1007/s10237-014-0609-1 ORIGINAL PAPER Growth and remodelling for profound circular wounds in skin

Abstract Wound healing studies both in vitro and in vivo have received a lot of attention recently. In vivo wound heal-ing is a multi-step process involving physiological factors such as fibrinogen forming the clot, the infiltrated inflam-matory cells, the recruited fibroblasts and the differentiated myofibroblasts as well as deposited collagens. All these actors play their roles at different times, aided by a cas-cade of morphogenetic agents and the result for the repair is approximatively successful but the imperfection is remained for large scars with fibrosis. Here, we want to study wound healing from the viewpoint of skin biomechanics, integrating the particular layered geometry of the skin, and the role of the neighbouring wound epidermis. After 2 days post-injury, it migrates towards the wound centre to cover the hole, the migration being coupled to proliferation at the wound bor-der. Such a process is dominated by the skin properties which varies with ages, locations, pathologies, radiations, etc. It is also controlled by passive (actin, collagen) and active (myo-fibroblasts) fibres. We explore a growth model in finite elas-ticity of a bilayer surrounding a circular wound, only the interior one being proliferative and contractile. We discuss the occurrence of an irregular wound geometry generated by stresses and show quantitatively that it results from the com-bined effects of the stiffness, the size of the wound, eventu-ally weakened by actin cables. Comparison of our findings is made with known observations or experiments in vivo