Techniques, systems, devices and materials are disclosed for implementing and fabricating drug delivery and imaging vehicles, which are activated in the body at a tissue of interest by focused ultrasound. In one aspect, a drug delivery vehicle can include a carrier having an outer membrane that envelopes an acoustic sensitizer particle and a payload substance to be delivered to the target tissue. The outer membrane can protect the acoustic sensitizer particle and the payload substance from degradation and opsonization. The outer membrane can be functionalized with a tumor targeting ligand to cause the drug delivery vehicle to selectively accumulate in a tumor region over other tissues, as well as with an agent to increase circulation time by reducing uptake from undesired body tissues, organs, and systems.