Ultrasound-Responsive Microdroplets for Multi-Drug Delivery Applications

The controlled release of multiple drugs represents an exciting avenue that can be exploited for targeted therapies and for promoting tissue regeneration. In this context, perfluorocarbon droplets are promising ultrasound-responsive carriers, which can release their cargo upon acoustic droplet vaporization. In this study, we investigate the release behavior of two different droplet types, in response to low-frequency (38 kHz) and low-pressure (50-100 kPa) ultrasound. These two droplet formulations, consisting of the same perfluoropentane core but different shells (phospholipid, surfactant-based), are designed to respond to different US pressures. Therefore, they can be triggered separately by modulating the acoustic pressure, potentially enabling the ultrasound-controlled, temporally independent delivery of two drugs.