Novel medical devices and uses thereof for lining a blood vessel and/or treating an aneurysm are disclosed herein. The device comprises a non-metallic expandable tubular structure, implantable in a body vessel and being made, at least in part, from a polymeric system characterized by a stiffness which changes upon stimulation under physiological conditions. Novel polymeric systems are further disclosed herein, which are configured to produce a polymeric material upon stimulation under physiological conditions, such that a stiffness of said polymeric material is higher than a stiffness of said system. Uses of polymer systems in the manufacture of a device are further disclosed.
