The invention describes an article made from chitosan-coated metal, where an impermeable chitosan layer having a barrier action is present on the metal through electrochemical polarisation in a chitosan-containing solution. The incorporation of biologically active components into the chitosan coating enables the coating to be matched to various applications and the bio-compatibility of correspondingly modified surfaces to be increased. Metallic articles or surfaces coated in this way are used, for example, as material for medical implants.