Abstract: A microbubble composition, comprising: a plurality of microbubbles, a microbubble comprising a noble gas and/or perfluorocarbon encapsulated within a shell that comprises one or more of a lipid, a protein, or a polymer, and a microbubble optionally defining a cross-sectional dimension in the range of from about 0.5 to about 20 micrometers. A method, comprising forming a composition according to the present disclosure. A method, comprising administering a microbubble composition according to the present disclosure to a subject, the composition optionally comprising echogenic phospholipid microbubbles. A method, comprising: (a) identifying, with the application of energy, the location of a microbubble composition according to the present disclosure, the energy optionally being ultrasound, (b) controllably effecting rupture of microbubbles of a microbubble composition of the present disclosure, the rupture optionally being effected by application of ultrasound, or both (a) and (b).