用于肾结石微创治疗的带有钙粘附部分的脂质壳微泡的实验观察与数值模拟
Experimental observations and numerical modeling of lipid-shell microbubbles with calcium-adhering moieties for minimally-invasive treatment of urinary stones.
作者信息
Pishchalnikov Yuri A, Behnke-Parks William, Maeda Kazuki, Colonius Tim, Mellema Matthew, Hopcroft Matthew, Luong Alice, Wiener Scott, Stoller Marshall L, Kenny Thomas, Laser Daniel J
机构信息
R&D, Applaud Medical, Inc., San Francisco, CA, 94107.
Applaud Medical, Inc., San Francisco, CA, 94107.
出版信息
Proc Meet Acoust. 2018;35(1). doi: 10.1121/2.0000958. Epub 2019 Jan 17.
A novel treatment modality incorporating calcium-adhering microbubbles has recently entered human clinical trials as a new minimally-invasive approach to treat urinary stones. In this treatment method, lipid-shell gas-core microbubbles can be introduced into the urinary tract through a catheter. Lipid moities with calcium-adherance properties incorporated into the lipid shell facilitate binding to stones. The microbubbles can be excited by an extracorporeal source of quasi-collimated ultrasound. Alternatively, the microbubbles can be excited by an intraluminal source, such as a fiber-optic laser. With either excitation technique, calcium-adhering microbubbles can significantly increase rates of erosion, pitting, and fragmentation of stones. We report here on new experiments using high-speed photography to characterize microbubble expansion and collapse. The bubble geometry observed in the experiments was used as one of the initial shapes for the numerical modeling. The modeling showed that the bubble dynamics strongly depends on bubble shape and stand-off distance. For the experimentally observed shape of microbubbles, the numerical modeling showed that the collapse of the microbubbles was associated with pressure increases of some two-to-three orders of magnitude compared to the excitation source pressures. This in-vitro study provides key insights into the use of microbubbles with calcium-adhering moieties in treatment of urinary stones.
一种结合钙黏附微泡的新型治疗方式最近已进入人体临床试验,成为治疗尿路结石的一种新的微创方法。在这种治疗方法中,脂质壳气体核微泡可通过导管引入尿路。掺入脂质壳中的具有钙黏附特性的脂质部分有助于与结石结合。微泡可由体外准直超声源激发。或者,微泡可由腔内光源(如光纤激光)激发。无论采用哪种激发技术,钙黏附微泡都能显著提高结石的侵蚀、点蚀和破碎率。我们在此报告使用高速摄影来表征微泡膨胀和坍塌的新实验。实验中观察到的气泡几何形状被用作数值建模的初始形状之一。建模表明,气泡动力学强烈依赖于气泡形状和间距。对于实验观察到的微泡形状,数值建模表明,与激发源压力相比,微泡的坍塌与压力增加约两到三个数量级有关。这项体外研究为在尿路结石治疗中使用带有钙黏附部分的微泡提供了关键见解。