Abstract: A device which can be implanted in the body and comprises an electrically conducting support covered with a layer of electrically conducting polymer, to which layer is attached at least one biologically active substance of an anionic or cationic nature. The deposition of the polymer is carried out, in a first stage, by electropolymerization directly directly on the support or, according to an alternative form, by deposition of the polymer in solution on the support. In a second stage, electrochemical oxidation or reduction is conducted and the biologically active substance with an anionic or cationic nature is attached to the polymer.

Abstract: The polymer films of the invention contain reactive groups and are obtained from phenols of the formula ##STR1## in which R denotes an acyl group with 1 to 7 carbon atoms, a hydroxy, carboxy, alkoxycarbonyl, amino, alkylamino or phenylamino group, andn is an integer, which may be 0 in the case where R is an acyl group.The films are prepared by electrolytic polymerisation on metallic surfaces and can be used to graft various materials reacting therewith, as intermediate layers.