The present invention relates to a microbubble complex comprising a microbubble having an outer shell comprising a mixture of native and denatured albumin encapsulating a perfluorocarbon gas, a therapeutic agent, a bifunctional linker having one end attached to the therapeutic agent and the other attached to a ligand and wherein the ligand is bound to the other shell of the microbubble through hydrophobic interactions. Also included are methods for delivering the aforementioned microbubble complex to a tissue target.