Sub-micron droplets comprised of lipid stabilized perfluorocarbons have potential applications in therapeutics and targeted ultrasound imaging. Acoustic energy can provide spatial localization of these droplets to enhance targeted adhesion or for site localized therapy. With ultrasound frequencies in the clinical imaging range and acoustic pressures on the order of megaPascals, these droplets translate in the direction of acoustic wave propagation on the order of hundreds of microns per second. The mechanism for this displacement effect is a combination of radiation force and acoustic streaming. In an in-vitro flowing system, acoustic manipulation of targeted droplets increases targeted droplet retention to ligands on the vessel wall. Ultrasound also locally enhances the delivery of sub-micron particles to a cell monolayer.