Zeghimi A, Escoffre J M, Bouakaz A
Phys Biol. 2015 Nov 24;12(6):066007. doi: 10.1088/1478-3975/12/6/066007.
Sonoporation is a physical method that has been successfully used to deliver drugs into living cells both in vitro and in vivo for experimental and therapeutic purposes. Despite numerous studies on this topic, often reporting successful outcomes, very little is known about the mechanisms involved in the hypothesized membrane permeabilization processes. In this study, electron microscopy was used to investigate the ultra-structural modifications of cell membranes, induced by sonoporation. Here, we demonstrate that sonoporation in the presence of microbubbles induces the formation of a significant number of transient and permeant structures at the membrane level. These structures were transient with a half-life of 10 min and had a heterogeneous size distribution ranging from a few nanometers to 150 nm. We demonstrated that the number and the size of these structures were positively correlated with the enhanced intracellular uptake of small molecules. In addition, we showed that these structures were associated with caveolae-dependent endocytosis for two thirds of the recorded events, with the remaining one third related to non-specific routes such as membrane disruptions as well as caveolae-independent endocytosis. In conclusion, our observations provide direct evidences of the involvement of caveolae-endocytosis in cell membrane permeabilization to small molecules after sonoporation.
声孔效应是一种物理方法，已成功用于在体外和体内将药物输送到活细胞中，以用于实验和治疗目的。尽管对此主题进行了大量研究，且常常报告成功的结果，但对于假设的膜通透性过程所涉及的机制却知之甚少。在本研究中，使用电子显微镜来研究由声孔效应诱导的细胞膜超微结构修饰。在此，我们证明在微泡存在下的声孔效应会在膜水平诱导大量瞬时和永久性结构的形成。这些结构是瞬时的，半衰期为10分钟，并且具有从几纳米到150纳米的异质尺寸分布。我们证明这些结构的数量和大小与小分子细胞内摄取的增强呈正相关。此外，我们表明，在记录的事件中，三分之二的此类结构与小窝蛋白介导的内吞作用有关，其余三分之一与非特异性途径有关，如膜破坏以及非小窝蛋白介导的内吞作用。总之，我们的观察结果提供了直接证据，证明小窝蛋白介导的内吞作用参与了声孔效应后细胞膜对小分子的通透性。
