Department of Biomedical Engineering, Thoraxcenter, Erasmus University Medical Center, Office Ee2302, P.O. Box 2040, 3000, CA, Rotterdam, The Netherlands.
Department of Biomedical Engineering, Thoraxcenter, Erasmus University Medical Center, Office Ee2302, P.O. Box 2040, 3000, CA, Rotterdam, The Netherlands.
J Control Release. 2020 Jun 10;322:426-438. doi: 10.1016/j.jconrel.2020.03.038. Epub 2020 Apr 1.
Ultrasound insonification of microbubbles can locally increase vascular permeability to enhance drug delivery. To control and optimize the therapeutic potential, we need to better understand the underlying biological mechanisms of the drug delivery pathways. The aim of this in vitro study was to elucidate the microbubble-endothelial cell interaction using the Brandaris 128 ultra-high-speed camera (up to 25 Mfps) coupled to a custom-built Nikon confocal microscope, to visualize both microbubble oscillation and the cellular response. Sonoporation and opening of cell-cell contacts by single αβ-targeted microbubbles (n = 152) was monitored up to 4 min after ultrasound insonification (2 MHz, 100-400 kPa, 10 cycles). Sonoporation occurred when microbubble excursion amplitudes exceeded 0.7 μm. Quantification of the influx of the fluorescent model drug propidium iodide upon sonoporation showed that the size of the created pore increased for larger microbubble excursion amplitudes. Microbubble-mediated opening of cell-cell contacts occurred as a cellular response upon sonoporation and did not correlate with the microbubble excursion amplitude itself. The initial integrity of the cell-cell contacts affected the susceptibly to drug delivery, since cell-cell contacts opened more often when cells were only partially attached to their neighbors (48%) than when fully attached (14%). The drug delivery outcomes were independent of nonlinear microbubble behavior, microbubble location, and cell size. In conclusion, by studying the microbubble-cell interaction at nanosecond and nanometer resolution the relationship between drug delivery pathways and their underlying mechanisms was further unraveled. These novel insights will aid the development of safe and efficient microbubble-mediated drug delivery.
超声空化微泡可局部增加血管通透性，以增强药物递送。为了控制和优化治疗潜力，我们需要更好地了解药物递送途径的潜在生物学机制。本体外研究的目的是使用 Brandaris 128 超高速相机（高达 25 Mfps）与定制的尼康共聚焦显微镜结合，阐明微泡-内皮细胞相互作用，以可视化微泡振荡和细胞反应。监测到单个靶向 αβ 的微泡（n=152）的声孔作用和细胞间接触的打开，直到超声空化后 4 分钟（2 MHz，100-400 kPa，10 个周期）。当微泡位移振幅超过 0.7μm 时，发生声孔作用。声孔作用时荧光模型药物碘化丙啶的内流的定量表明，创建的孔的大小随着微泡位移振幅的增加而增大。微泡介导的细胞间接触的打开是声孔作用后的细胞反应，与微泡位移振幅本身无关。细胞间接触的初始完整性影响药物递送的易感性，因为当细胞仅部分与其相邻细胞附着时（48%），细胞间接触比完全附着时（14%）更容易打开。药物递送结果与非线性微泡行为、微泡位置和细胞大小无关。总之，通过在纳秒和纳米分辨率下研究微泡-细胞相互作用，进一步阐明了药物递送途径及其潜在机制之间的关系。这些新的见解将有助于开发安全有效的微泡介导的药物递送。
