title: Surface Charge Measurement of SonoVue, Definity and Optison: A Comparison of Laser Doppler Electrophoresis and Micro-Electrophoresis.
abstract: Microbubble (MB) contrast-enhanced ultrasonography is a promising tool for targeted molecular imaging. It is important to determine the MB surface charge accurately as it affects the MB interactions with cell membranes. In this article, we report the surface charge measurement of SonoVue, Definity and Optison. We compare the performance of the widely used laser Doppler electrophoresis with an in-house micro-electrophoresis system. By optically tracking MB electrophoretic velocity in a microchannel, we determined the zeta potentials of MB samples. Using micro-electrophoresis, we obtained zeta potential values for SonoVue, Definity and Optison of -28.3, -4.2 and -9.5 mV, with relative standard deviations of 5%, 48% and 8%, respectively. In comparison, laser Doppler electrophoresis gave -8.7, +0.7 and +15.8 mV with relative standard deviations of 330%, 29,000% and 130%, respectively. We found that the reliability of laser Doppler electrophoresis is compromised by MB buoyancy. Micro-electrophoresis determined zeta potential values with a 10-fold improvement in relative standard deviation.
authors: Department of Chemistry, Imperial College London, London, UK.
authors: Fairuzeta
authors: F
authors: Ja'afar
authors: Department of Bioengineering, Imperial College London, London, UK.
authors: Chee Hau
authors: CH
authors: Leow
authors: Department of Chemical Engineering, Imperial College London, London, UK.
authors: Valeria
authors: V
authors: Garbin
authors: Department of Chemistry, Imperial College London, London, UK; Department of Bioengineering, Imperial College London, London, UK.
authors: Charles A
authors: CA
authors: Sennoga
authors: Department of Bioengineering, Imperial College London, London, UK. Electronic address: mengxing.tang@imperial.ac.uk.
authors: Meng-Xing
authors: MX
authors: Tang
authors: Department of Chemistry, Imperial College London, London, UK.
authors: John M
authors: JM
authors: Seddon
mesh_terms: D000418:Albumins / Q000493:pharmacokinetics*; D003287:Contrast Media / Q000493:pharmacokinetics*; D004586:Electrophoresis; D005466:Fluorocarbons / Q000493:pharmacokinetics*; D045423:Microbubbles; D010743:Phospholipids / Q000493:pharmacokinetics*; D015203:Reproducibility of Results; D013459:Sulfur Hexafluoride / Q000493:pharmacokinetics*; D018608:Ultrasonography, Doppler
chemical_list: D000418:Albumins; D003287:Contrast Media; C099458:FS 069; D005466:Fluorocarbons; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride; C042852:perflutren
keywords: Definity; Laser Doppler electrophoresis; Micro-electrophoresis; Microbubbles; Optison; Particle tracking; SonoVue; Surface charge; Ultrasound contrast agents; Zeta potential