Center for Ultrasound Molecular Imaging and Therapeutics, University of Pittsburgh Medical Center, Pittsburgh, PA, USA; Department of Cardiology, First Affiliated Hospital of Jinan University, Guangzhou, China.
Center for Ultrasound Molecular Imaging and Therapeutics, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Ultrasound Med Biol. 2023 Apr;49(4):996-1006. doi: 10.1016/j.ultrasmedbio.2022.12.013. Epub 2023 Jan 24.
Ultrasound (US)-targeted microbubble (MB) cavitation (UTMC)-mediated therapies have been found to restore perfusion and enhance drug/gene delivery. Because of the potentially longer circulation time and relative ease of storage and reconstitution of polymer-shelled MBs compared with lipid MBs, we investigated the dynamic behavior of polymer microbubbles and their therapeutic potential for sonoreperfusion (SRP) therapy.
The fate of polymer MBs during a single long tone-burst exposure (1 MHz, 5 ms) at various acoustic pressures and MB concentrations was recorded via high-speed microscopy and passive cavitation detection (PCD). SRP efficacy of the polymer MBs was investigated in an in vitro flow system and compared with that of lipid MBs.
Microscopy videos indicated that polymer MBs formed gas-filled clusters that continued to oscillate, fragment and form new gas-filled clusters during the single US burst. PCD confirmed continued acoustic activity throughout the 5-ms US excitation. SRP efficacy with polymer MBs increased with pulse duration and acoustic pressure similarly to that with lipid MBs but no significant differences were found between polymer and lipid MBs.
These data suggest that persistent cavitation activity from polymer MBs during long tone-burst US excitation confers excellent reperfusion efficacy.
超声（US）靶向微泡（MB）空化（UTMC）介导的疗法已被发现可恢复灌注并增强药物/基因的递送。由于与脂质 MB 相比，聚合物壳 MB 具有潜在更长的循环时间和相对容易的储存和再形成，因此我们研究了聚合物微泡的动力学行为及其在声再灌注（SRP）治疗中的治疗潜力。
通过高速显微镜和被动空化检测（PCD）记录了在不同声压和 MB 浓度下单个长音爆照射（1 MHz，5 ms）期间聚合物 MB 的命运。在体外流动系统中研究了聚合物 MB 的 SRP 效果，并与脂质 MB 进行了比较。
显微镜视频表明，聚合物 MB 在单个 US 爆发期间形成了继续振荡、碎裂并形成新的充气簇的充气簇。PCD 证实了在整个 5ms US 激发过程中持续的声活性。聚合物 MB 的 SRP 效果随着脉冲持续时间和声压的增加而增加，与脂质 MB 的效果相似，但聚合物和脂质 MB 之间没有发现显著差异。
这些数据表明，在长音爆 US 激发期间聚合物 MB 的持续空化活性赋予了优异的再灌注效果。
