Ultrasound-enhanced extravasation of multifunctional nanodroplets from leaky vessel

Poorly organized vascular architecture of tumor tissue allows extravasation of drug-loaded nanoparticles through the large interendothelial gaps. Extravasated perfluorocarbon nanodroplets can convert into microbubbles under ultrasound irradiation to imaging or deliver drug for tumor treatment. However an increased interstitial fluid pressure in tumor tissue hinders convectional transport of drug carriers across blood vessel walls, thus extravasation of sufficient amounts of droplets remains a major challenge. In this paper, we propose an ultrasound-enhanced extravasation strategy using synergetic effect of acoustic radiation force and cavitation enhanced penetration.