“Petal effect”-inspired superhydrophobic and highly adhesive coating on magnesium with enhanced corrosion resistance and biocompatibility

Abstract

With properties of complete degradation and favorable mechanical behavior, Mg and its alloys are regarded as the next generation medical metal materials. However, fast degradation and poor surface biocompatibility hinder their clinical applications. Inspired by the “petal effect”, we successfully constructed a superhydrophobic and highly adhesive coating on pure Mg via a simple hydrothermal treatment in a solution containing sodium oleate. The superhydrophobicity of the fabricated coating results from its flake-like micro-na-nostructure and the low-surface-energy oleate group. Water droplet on the superhydrophobic coating cannot roll off even when the sample is turned upside down, owing to the sealed air-pockets and the van der Waals’ attraction at the solid-liquid interface, indicating a highly adhesive force. The chemical and mechanical stability of the superhydrophobic coating were measured. Potentiodynamic polarization and electrochemical impedance spectroscopy measurements suggest enhanced corrosion resistance of the as-prepared sample. Furthermore,cellcytotoxicity,migrationandadhesiondataof human umbilical vein endothelial cells (HUVECs) reveal an improved cytocompatibility of the modified surface. Finally, hemolysis assay and platelet adhesion assay suggest an improved hemocompatibility. It is believed that the facile and low-cost method can expand the new application of super-hydrophobicsurfacewithhighlyadhesiveonMginbiomedical fields.