Gailliègue Florian N, Tamošiūnas Mindaugas, André Franck M, Mir Lluis M
Institut Gustave Roussy, Metabolic and Systemic Aspects of the Oncogenesis (METSY), Université Paris-Saclay, CNRS, 94805 Villejuif, France.
Biophotonics Laboratory, Institute of Atomic Physics and Spectroscopy, University of Latvia, 19 Raina Blvd., LV-1586 Rīga, Latvia.
Pharmaceutics. 2021 Jun 8;13(6):847. doi: 10.3390/pharmaceutics13060847.
Sonoporation is the process of cell membrane permeabilization, due to exposure to ultrasounds. There is a lack of consensus concerning the mechanisms of sonoporation: Understanding the mechanisms of sonoporation refines the choice of the ultrasonic parameters to be applied on the cells. Cells' classical exposure systems to ultrasounds have several drawbacks, like the immersion of the cells in large volumes of liquid, the nonhomogeneous acoustic pressure in the large sample, and thus, the necessity for magnetic stirring to somehow homogenize the exposure of the cells. This article reports the development and characterization of a novel system allowing the exposure to ultrasounds of very small volumes and their observation under the microscope. The observation under a microscope imposes the exposure of cells and Giant Unilamellar Vesicles under an oblique incidence, as well as the very unusual presence of rigid walls limiting the sonicated volume. The advantages of this new setup are not only the use of a very small volume of cells culture medium/microbubbles (MB), but the presence of flat walls near the sonicated region that results in a more homogeneous ultrasonic pressure field, and thus, the control of the focal distance and the real exposure time. The setup presented here comprises the ability to survey the geometrical and dynamical aspects of the exposure of cells and MB to ultrasounds, if an ultrafast camera is used. Indeed, the setup thus fulfills all the requirements to apply ultrasounds conveniently, for accurate mechanistic experiments under an inverted fluorescence microscope, and it could have interesting applications in photoacoustic research.
声穿孔是指由于暴露于超声波而导致细胞膜通透性增加的过程。关于声穿孔的机制目前尚无定论：了解声穿孔机制有助于优化应用于细胞的超声参数选择。细胞传统的超声暴露系统存在若干缺点，例如将细胞浸没于大量液体中、大样本中声压不均匀，因此需要磁力搅拌以使细胞暴露均匀化。本文报道了一种新型系统的开发与特性，该系统可使极少量体积的样本暴露于超声波下，并能在显微镜下进行观察。在显微镜下观察要求细胞和巨型单层囊泡在斜入射下暴露，以及存在限制超声处理体积的刚性壁这种非常特殊的情况。这种新装置的优点不仅在于使用极少量体积的细胞培养基/微泡（MB），还在于超声处理区域附近存在平坦壁面，这会产生更均匀的超声压力场，从而实现对焦距和实际暴露时间的控制。如果使用超快相机，这里介绍的装置具备研究细胞和微泡暴露于超声波时的几何和动态方面的能力。实际上，该装置满足了在倒置荧光显微镜下方便地应用超声波进行精确机理实验的所有要求，并且在光声研究中可能具有有趣的应用。
