The present invention relates to a a nanowire array for electrically-controlled elution of a therapeutic composition comprising a plurality of nanoscopic-sized wires, nanowires, attached to an electrically conducting solid support, said nanowires formed from electroactive conjugated polymer containing or doped with said therapeutic composition coated over a plurality of nanoscopic sized electrically conducting protrusions. It also relates to a method for preparing a nanowire array and an electrode.