Dermis mechanical behaviour: influence of cells removal treatment

The mechanical behaviour of skin is very important as regards dermatology, surgery and impact trauma. Engineered skin substitutes can bring significant medical benefit in particular to patients with extensive burn wounds, even if current skin substitutes do not restore normal skin anatomy and its natural mechanical properties. This work considers the mechanical characterization of a particular layer of skin: dermis. Dermis can be used as filling material and as support in different areas of reconstructive plastic surgery such as post mastectomy reconstructive surgery and abdominal surgery. The aim was to verify the influence of the decellularization treatment on its properties. The specimens were subjected to uniaxial static tests performed with Bose Electroforce® 3200 and experimental data were represented with engineering and real time stress-strain curves. To begin, descriptive parameters were identified for stress vs. strain curves, such as ultimate tensile strength and maximum Young’s modulus, and they were subsequently compared through multivariate analysis of variance to determine the influence of specimen cut orientation and decellularization treatment duration. Dermis, that had been decellularized over 5 or 6 weeks, exhibited mechanical properties comparable with natural ones and ultimate tensile strength and maximum Young’s modulus were shown to be considerably higher in real time curves than in engineering ones.