Corinne Nardin

Hydrogels are known for their biocompatibility, multifunctionality and tunability, as well as their antimicrobial properties. Hydrogel and nanocomposite coatings were developed to inhibit the adhesion of Nitratidesulfovibrio vulgaris and prevent biocorrosion of aluminum 7075 substrates. Using a UV photoinduced synthesis approach, 2-hydroxyethyl methacrylate (HEMA)-based matrices were polymerized with the simultaneous in situ formation of silver nanoparticles (AgNPs). Physicochemical characterization (FTIR, UV-Vis, TEM, and contact angle measurements) validated the coating properties and confirmed the retention of its hydration essential for antifouling. The study highlights a synergistic effect where hydration, ionic charges, and AgNPs effectively block bacterial adhesion. Results from microbiological and electrochemical assays indicate that these coatings not only ensure excellent adhesion to the substrate but also significantly reduce bacterial counts and minimize chemical corrosion potential, providing a robust solution for material protection in aggressive environments.

The viscoelastic properties of human skin are fundamental to its ability to maintain structural integrity. These mechanical characteristics are crucial for understanding skin behavior and have several important applications: (i) documenting the natural evolution of skin over time; (ii) providing an objective method to evaluate the efficacy of medical or dermo-cosmetic treatments; and (iii) identifying and quantifying pathological changes that affect the mechanical properties of the tissue. To address these needs, a novel instrument has been developed specifically to assess the viscoelastic properties of ex vivo human skin explants, maintained in physiological-like conditions over seven days. This device, described herein, enables both conventional tensile testing and dynamic mechanical analysis. The latter allows for the characterization of the skin’s two primary mechanical components—elasticity and energy dissipation—across a range of frequencies, thereby enabling the differentiation of these phenomena. Initial studies focused on repeatability and reproducibility using skin explants, confirming the robustness of both the instrument and the measurement protocol for ex vivo skin characterization. A comprehensive example of mechanical analysis is presented to illustrate the capabilities of the device. Ultimately, this instrument offers a promising approach for evaluating the viscoelastic behavior of human skin explants and for monitoring the impact of various stressors on skin mechanics over time.