Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA.
Ultrasound Med Biol. 2010 Mar;36(3):419-29. doi: 10.1016/j.ultrasmedbio.2009.11.009. Epub 2010 Feb 4.
Cavitation properties of block copolymer stabilized perfluoropentane nanoemulsions have been investigated. The nanoemulsions were stabilized by two biodegradable amphiphilic block copolymers differing in the structure of the hydrophobic block, poly(ethylene oxide)-co-poly(L-lactide) (PEG-PLLA) and poly(ethylene oxide)-co-polycaprolactone (PEG-PCL). Cavitation parameters were measured in liquid emulsions and gels as a function of ultrasound pressure for unfocused or focused 1-MHz ultrasound. Acoustic droplet vaporization preceded generation of acoustic cavitation in liquid matrices and gels. Both stable and inertial cavitation was observed for focused ultrasound while only stable cavitation was observed for unfocused ultrasound.
已研究了两亲嵌段共聚物稳定的全氟戊烷纳米乳的空化特性。纳米乳分别由两种结构不同的生物可降解两亲性嵌段共聚物稳定:聚(环氧乙烷)-共-聚(L-丙交酯)(PEG-PLLA)和聚(环氧乙烷)-共-聚己内酯(PEG-PCL)。在液体乳液和凝胶中,作为未聚焦或聚焦 1MHz 超声的超声压力的函数,测量了空化参数。在液体基质和凝胶中,声致液滴蒸发先于声空化的产生。对于聚焦超声,观察到了稳定和惯性空化,而对于非聚焦超声,仅观察到了稳定空化。