The Need for Size-Isolated Monodisperse Microbubbles
Microbubble size polydispersity is a major problem in medical research with ultrasound contrast agents (UCAs). Other commercially available microbubble agents have inherently polydisperse (broad) or limited sizes with discrepant number and volume weighted size distributions (see graphs below). This polydispersity can lead to inconsistent acoustic or therapeutic response and sub-optimal use of research funds because microbubble resonance, scattering and attenuation under ultrasound is strongly dependent on size. For example, changing the diameter of a non-shelled microbubble from 1 to 5 μm will change the resonance frequency from 5 to 0.7 MHz.
Our separation method can provide monodisperse microbubble classes (1-2, 3-4, 4-5, 5-8 microns) with consistent number and volume weighted distributions (see graphs below), which allows researchers to determine the microbubble size intended for ultrasound imaging or targeted drug delivery applications. As an example, researchers adapting 4-5 and 5-8 micron size-selected microbubbles for Focused Ultrasound (FUS) assisted blood-brain barrier (BBB) opening, successfully transitioned from mice to monkey trials (see literature).