· A new targeting strategy will be presented that uses ultrasonic manipulation of ligand presentation. The surface architecture is designed to be stealth in the unperturbed state – i.e., the tethered ligand is buried by a polymeric overbrush that conceals it from plasma components. Application of ultrasound radiation force not only pushes the microbubble against the endothelium, but also transiently reveals the ligand for specific adhesion. Results show reduced complement activation in serum and efficient ultrasound-mediated targeting to plated cells.

· Loading DNA onto microbubbles is desirable for applications in localized gene therapy with ultrasound. Recent experimental work will be presented that details the adsorption and multilayer buildup of DNA molecules onto the microbubble shell. Results show significant enhancement in DNA loading with interesting effects on ultrasound compliance to oscillation in the ultrasound field. In addition to their applications, microbubbles also provide an interesting platform on which to study self-assembled lipid membranes. The talk will illustrate findings on monolayer collapse and shedding transitions, phase behavior, microstructural domain growth and stability, and gas permeability.