Formulation of Perfluorocarbon-Filled Droplets for Ultrasound-Mediated Applications
PublisherThe University of Arizona.
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AbstractMicrobubbles and nanodroplets are tools used in medicine for diagnosis and therapy. Probubbles are initially submicrometer droplets that become microbubbles in tumors as a result of ultrasonic force. The aim of this investigation was to determine vaporization thresholds of perfluorocarbon (PFC) droplets as a function of PFC boiling point and droplet size. PFC droplets with boiling points -1. 7 to 56.6°C were formulated followed by acoustic droplet vaporization (ADV) and stability testing. Under ultrasound acoustic outputs used, perfluorohexane (PFH) droplets did not vaporize while perfluoro(-2- methyl-3-pentanone) (PFMP), perfluoropentane (PFP), and perfluorobutane (PFB) droplets did vaporize. The acoustic output required to vaporize droplets decreased with decreasing boiling point. Vaporization threshold is a function of size with larger diameter droplets requiring less ultrasound output to vaporize. PFH, PFMP, and PFP droplets remained stable after 16 weeks in 4°C and 23°C environments, but PFMP and PFP evaporated entirely in a 40°C oven after 12 weeks.