Flow cytometric characterization and sorting of ultrasound contrast agents
Creators: name: Mujić, Maja
name: Kotopoulis, Spiros
name: Delalande, Anthony
name: Enger, Marianne
name: Gilja, Odd Helge
name: Mc Cormack, Emmet
name: Postema, Michiel
name: Gjertsen, Bjørn Tore
Publisher: name: Zenodo
Year: 2012

description: Ultrasound contrast agents consist of microscopically small gas bubbles encapsulated by elastic shells, and are regularly employed in ultrasound blood pool perfusion diagnostics and currently explored as drug delivery vehicles. Successful development of functional ultrasound contrast imaging demands precise and effective microbubble evaluation techniques. We have examined flow cytometry as a method for in vitro quantification, optical characterization and sorting of microbubbles with flexible lipid shell or albumin shell. Flow cytometry provided reproducible side and forward scatter analysis and quantification of gas filled microbubbles enumeration, at various pressure levels and fluid flow speeds. Quantification allowed determination of the static microbubble stability, indicating increased stability at 4°C compared with storage at ambient temperature. Flow cytometry allowed detection of microbubbles in mixture with cell lines or whole blood ex vivo. Furthermore, flow cytometry analysis permitted microbubble sorting by size or fluorescence, allowing evaluation of isolated microbubble populations. We anticipate that flow cytometry will be a reliable technology for analysis of novel modified microbubbles for use in clinical ultrasonography.
description: {"references": ["Basic and New Aspects of Gastrointestinal Ultrasonography, ed. \u00d8degaard S, Gilja OH, and G. H. Vol. 3. 2005, Singapore: World Scientific. 502.", "Postema, M. and O.H. Gilja, Contrast-enhanced and targeted ultrasound. World J Gastroenterol, 2011. 17(1): p. 28-41.", "Postema, M. and O.H. Gilja, Ultrasound-directed drug delivery. Curr Pharm Biotechnol, 2007. 8(6): p. 355-61.", "Postema, M., Fundamentals of Medical Ultrasonics 2011, London: Spon Press.", "Alexandrov, A.V. et al., Ultrasound-enhanced systemic thrombolysis for acute ischemic stroke. N Engl J Med, 2004. 351(21): p. 2170-8.", "Klibanov, A.L. et al., Targeted ultrasound contrast agent for molecular imaging of inflammation in high-shear flow. Contrast Media Mol Imaging, 2006. 1(6): p. 259-66.", "Pysz, M.A. et al., Antiangiogenic cancer therapy: monitoring with molecular US and a clinically translatable contrast agent (BR55). Radiology, 2010. 256(2): p. 519-27.", "Dijkmans, P.A. et al., Microbubbles and ultrasound: from diagnosis to therapy. Eur J Echocardiogr, 2004. 5(4): p. 245-56.", "van Wamel, A. et al., Vibrating microbubbles poking individual cells: drug transfer into cells via sonoporation. J Control Release, 2006. 112(2): p. 149-55.", "Schneider, M., Molecular imaging and ultrasound-assisted drug delivery. J Endourol, 2008. 22(4): p. 795-802.", "Klibanov, A.L., Microbubble contrast agents: targeted ultrasound imaging and ultrasound- assisted drug-delivery applications. Invest Radiol, 2006. 41(3): p. 354-62.", "Bull, J.L., The application of microbubbles for targeted drug delivery. Expert Opin Drug Deliv, 2007. 4(5): p. 475-93.", "Mitragotri, S., Healing sound: the use of ultrasound in drug delivery and other therapeutic applications. Nat Rev Drug Discov, 2005. 4(3): p. 255-60.", "Delalande, A. et al., Ultrasound and microbubble-assisted gene delivery in Achilles tendons: Long lasting gene expression and restoration of fibromodulin KO phenotype. J Control Release, 2011. 156(2): p. 223-230.", "Bao, S., B.D. Thrall, and D.L. Miller, Transfection of a reporter plasmid into cultured cells by sonoporation in vitro. Ultrasound Med Biol, 1997. 23(6): p. 953-9.", "Prentice P, C.A., Dholakia K, Prausnitz M and Campbell P, Membrane disruption by optically controlled microbubble cavitation. Nature Physics, 2005. 1: p. 107 - 110.", "Stringham, S.B. et al., Over-pressure suppresses ultrasonic-induced drug uptake. Ultrasound Med Biol, 2009. 35(3): p. 409-15.", "Schlicher, R.K. et al., Mechanism of intracellular delivery by acoustic cavitation. Ultrasound Med Biol, 2006. 32(6): p. 915-24."]}