Functional drug-delivery vehicles consisting of Ag-embedded bilayer membranes of a peptidic lipid nanotube (LNT) are synthesized. The Ag-LNTs possess antimicrobial ability against E coli, contributing to the release of Ag+ into the aqueous culture. The Ag-LNTs may be applicable to the delivery of DNA or biotechnological drugs that are usually sensitive to changes in their surroundings.