微泡制剂影响聚焦超声在脑内暴露后的炎症反应。
Microbubble formulation influences inflammatory response to focused ultrasound exposure in the brain.
机构信息
Physical Science Platform, Sunnybrook Research Institute, Toronto, Canada.
Department of Medical Biophysics, University of Toronto, Toronto, Canada.
出版信息
Sci Rep. 2020 Dec 9;10(1):21534. doi: 10.1038/s41598-020-78657-9.
Focused ultrasound and microbubble (FUS + MB)-mediated blood-brain barrier (BBB) permeability enhancement can facilitate targeted brain-drug delivery. While controlling the magnitude of BBB permeability enhancement is necessary to limit tissue damage, little work has attempted to decouple these concepts. This work investigated the relationship between BBB permeability enhancement and the relative transcription of inflammatory mediators 4 h following sonication. Three microbubble formulations, Definity, BG8774, and MSB4, were compared, with the dose of each formulation normalized to gas volume. While changes in the transcription of key proinflammatory mediators, such as Il1b, Ccl2, and Tnf, were correlated to the magnitude of BBB permeability enhancement, these correlations were not independent of microbubble formulation; microbubble size distribution may play an important role, as linear regression analyses of BBB permeability magnitude versus differential gene expression for these proinflammatory mediators revealed significantly greater slopes for MSB4, a monodisperse microbubble with mean diameter of 4 μm, compared to Definity or BG8774, both polydisperse microbubbles with mean diameters below 2 μm. Additionally, the function of an acoustic feedback control algorithm, based on the detection threshold of ultraharmonic emissions, was assessed. While this control strategy was effective in limiting both wideband emissions and red blood cell extravasation, microbubble formulation was found to influence the magnitude of BBB leakage and correlations to acoustic emissions. This work demonstrates that while the initial magnitude of FUS + MB-mediated BBB permeability enhancement has a clear influence on the subsequent inflammatory responses, microbubble characteristics influence these relationships and must also be considered.
聚焦超声和微泡(FUS+MB)介导的血脑屏障(BBB)通透性增强可以促进靶向脑内药物输送。虽然控制 BBB 通透性增强的幅度对于限制组织损伤是必要的,但很少有工作试图将这些概念分离。本研究调查了超声后 4 小时 BBB 通透性增强与炎症介质相对转录之间的关系。比较了三种微泡制剂,Definity、BG8774 和 MSB4,每种制剂的剂量均按气体体积归一化。尽管关键促炎介质(如 Il1b、Ccl2 和 Tnf)的转录变化与 BBB 通透性增强幅度相关,但这些相关性不受微泡制剂的影响;微泡大小分布可能起着重要作用,因为 BBB 通透性幅度与这些促炎介质的差异基因表达的线性回归分析显示,MSB4 的斜率显著大于 Definity 或 BG8774,MSB4 是一种单分散微泡,平均直径为 4μm,而 Definity 或 BG8774 均为平均直径小于 2μm 的多分散微泡。此外,还评估了基于超谐波发射检测阈值的声反馈控制算法的功能。虽然这种控制策略在限制宽带发射和红细胞渗出方面是有效的,但微泡制剂被发现影响 BBB 泄漏的幅度和与声发射的相关性。本工作表明,尽管 FUS+MB 介导的 BBB 通透性增强的初始幅度对随后的炎症反应有明显影响,但微泡特性影响这些关系,也必须加以考虑。