Cytosolic protein delivery using ultrasound‐guided vaporization of perfluorocarbon nano‐droplets

Abstract

AbstractUltrasound‐guided protein delivery is promising for site‐specific control of cellular functions in the deep interior of the body in a noninvasive manner. Herein, we propose a method for cytosolic protein delivery based on ultrasound‐guided intracellular vaporization of perfluorocarbon nano‐droplets. The nano‐droplets were conjugated with cargo proteins through a bio‐reductively cleavable linker and introduced into living cells via antibody‐mediated binding to a cell‐surface receptor, which gets internalized through endocytosis. After the cells were exposed to ultrasound for endosomal escape of proteins, the ultrasound‐responsive cytosolic release of a cargo enzyme was confirmed by visualizing the hydrolysis of the fluorogenic substrate using confocal microscopy. Moreover, a significant decrease in cell viability was achieved via the release of a cytotoxic protein in response to ultrasound treatment. The results of this study provide the proof of a principle that protein‐conjugated nano‐droplets can be used as carriers in ultrasound‐guided cytosolic delivery of proteins.