Print Email Facebook Twitter Internalization of targeted microbubbles by endothelial cells and drug delivery by pores and tunnels Title Internalization of targeted microbubbles by endothelial cells and drug delivery by pores and tunnels Author Beekers, Inés (Erasmus MC; Ortec B.V.) Langeveld, Simone A.G. (Erasmus MC) Meijlink, Bram (Erasmus MC) van der Steen, A.F.W. (Erasmus MC) de Jong, N. (TU Delft ImPhys/Medical Imaging; Erasmus MC) Verweij, M.D. (TU Delft ImPhys/Medical Imaging; Erasmus MC) Kooiman, Klazina (Erasmus MC) Date 2022 Abstract Ultrasound insonification of microbubbles can locally enhance drug delivery by increasing the cell membrane permeability. To aid development of a safe and effective therapeutic microbubble, more insight into the microbubble-cell interaction is needed. In this in vitro study we aimed to investigate the initial 3D morphology of the endothelial cell membrane adjacent to individual microbubbles (n = 301), determine whether this morphology was affected upon binding and by the type of ligand on the microbubble, and study its influence on microbubble oscillation and the drug delivery outcome. High-resolution 3D confocal microscopy revealed that targeted microbubbles were internalized by endothelial cells, while this was not the case for non-targeted or IgG1-κ control microbubbles. The extent of internalization was ligand-dependent, since αvβ3-targeted microbubbles were significantly more internalized than CD31-targeted microbubbles. Ultra-high-speed imaging (~17 Mfps) in combination with high-resolution confocal microscopy (n = 246) showed that microbubble internalization resulted in a damped microbubble oscillation upon ultrasound insonification (2 MHz, 200 kPa peak negative pressure, 10 cycles). Despite damped oscillation, the cell's susceptibility to sonoporation (as indicated by PI uptake) was increased for internalized microbubbles. Monitoring cell membrane integrity (n = 230) showed the formation of either a pore, for intracellular delivery, or a tunnel (i.e. transcellular perforation), for transcellular delivery. Internalized microbubbles caused fewer transcellular perforations and smaller pore areas than non-internalized microbubbles. In conclusion, studying microbubble-mediated drug delivery using a state-of-the-art imaging system revealed receptor-mediated microbubble internalization and its effect on microbubble oscillation and resulting membrane perforation by pores and tunnels. Subject Drug deliveryMicrobubblesSonoporationTranscellular perforationUltrasound To reference this document use: http://resolver.tudelft.nl/uuid:90cdbd78-d2cb-451e-8b6d-58bbccae8cb6 DOI https://doi.org/10.1016/j.jconrel.2022.05.008 ISSN 0168-3659 Source Journal of Controlled Release: official journal of the Controlled Release Society, 347, 460-475 Part of collection Institutional Repository Document type journal article Rights © 2022 Inés Beekers, Simone A.G. Langeveld, Bram Meijlink, A.F.W. van der Steen, N. de Jong, M.D. Verweij, Klazina Kooiman Files PDF 1_s2.0_S0168365922002620_main.pdf 11.7 MB Close viewer /islandora/object/uuid:90cdbd78-d2cb-451e-8b6d-58bbccae8cb6/datastream/OBJ/view