Ultrasound has long been an important tool for medical imaging. Recently, medical researchers have demonstrated that focused ultrasound waves can also improve the delivery of therapeutic agents such as drugs and genetic material. The waves form bubbles that make cell membranes—as well as synthetic membranes enclosing drug-carrying vesicles—more permeable. However, the bubble-membrane interaction is not well understood.
Soft lipid shells, insoluble in water, are a key component of the barrier that surrounds cells. They are also used as drug nanocarriers: nanometer size particles of fat or lipid molecules that carry the drug to be delivered locally at the diseased organ or location, and which can be injected inside the body.
The lipid shell can be “popped” by soundwaves, which can be focused to a spot around the size of a grain of rice, resulting in a highly localized opening of barriers potentially overcoming major challenges in drug delivery.