The chitosan coating and processing effect on the physiological corrosion behaviour of porous magnesium monoliths

[Display omitted] •Porous Mg monoliths with different porosities were successfully surface modified by chitosan coatings.•Chitosan coated 40% porosity monolith properties are close to the properties of bone, suitable candidate for biomedical application.•The corrosion studies show that chitosan coating control the degradation of magnesium. The present study evaluates the corrosion resistance effect of chitosan coating onto porous magnesium (Mg) monoliths with porosities of 14–40 vol.%, prepared by sintering of Mg powder with NH4HCO3 used as spacer particles. The dip-coated chitosan was found to interact with corrosion products (Mg(OH)2 and MgO) via hydrogen bonding, providing the physiological stability and the corrosion resistance, at the same time affecting the mineralization process towards amorphous apatite with a small contribution of crystalline hydroxyapatite(HAP). The electrochemical studies reveal that porosity increases, and that the coating process affects the corrosion resistance positively. However, the values for compression strength (17–72MPa) and elastic modulus (12–26MPa) of chitosan-coated monolith indicate its applicability as a supporting, rather than self-standing implantation material.