Precise, low-intensity triggered release in biological systems using ultrasound-responsive antibubbles

Antibubbles are an emerging carrier for low-intensity, ultrasound-triggered release that can carry large payloads in their liquid cores. As we have previously shown, antibubbles can release their payloads at adjustable pressures, ranging from as low as a few kPa (MI < 0.01) to above a few hundred kPa (MI > 0.2). The specific release threshold and behavior can be determined during fabrication, making it possible to realize either single-shot release or multi-stage dosing of a payload. These characteristics make antibubbles an attractive alternative to conventional microbubble delivery agents particularly in sensitive tissues where risks of ultrasound need to be kept to a minimum. In this talk, we discuss recent experiments in which we demonstrate triggered release from antibubbles in in vitro biological systems. We show that payload release can be controlled using patterned or focused ultrasound fields, and we characterize the distribution and cellular uptake of payloads inside cell-laden matrices. These results not only demonstrate the potential of antibubbles for therapeutic applications but also open the door to targeted delivery in complex tissue scaffolds for tissue engineering.