title: Characterisation of Liposome-Loaded Microbubble Populations for Subharmonic Imaging.
abstract: Therapeutic microbubbles could make an important contribution to the diagnosis and treatment of cancer. Acoustic characterisation was performed on microfluidic generated microbubble populations that either were bare or had liposomes attached. Through the use of broadband attenuation techniques (3-8 MHz), the shell stiffness was measured to be 0.72 ± 0.01 and 0.78 ± 0.05 N/m and shell friction was 0.37 ± 0.05 and 0.74 ± 0.05 × 10-6kg/s for bare and liposome-loaded microbubbles, respectively. Acoustic scatter revealed that liposome-loaded microbubbles had a lower subharmonic threshold, occurring from a peak negative pressure of 50 kPa, compared with 200 kPa for equivalent bare microbubbles. It was found that liposome loading had a negligible effect on the destruction threshold for this microbubble type, because at a mechanical index >0.4 (570 kPa), 80% of both populations were destroyed.
authors: School of Electronic and Electrical Engineering, University of Leeds, Leeds, UK; Division of Biomedical Imaging, University of Leeds, Leeds, UK. Electronic address: j.r.mclaughlan@leeds.ac.uk.
authors: James R
authors: JR
authors: McLaughlan
authors: School of Electronic and Electrical Engineering, University of Leeds, Leeds, UK.
authors: Sevan
authors: S
authors: Harput
authors: School of Physics and Astronomy, University of Leeds, Leeds, UK; Department of Physics, Faculty of Science, Mansoura University, Mansoura City, Egypt.
authors: Radwa H
authors: RH
authors: Abou-Saleh
authors: School of Physics and Astronomy, University of Leeds, Leeds, UK.
authors: Sally A
authors: SA
authors: Peyman
authors: School of Physics and Astronomy, University of Leeds, Leeds, UK.
authors: Stephen
authors: S
authors: Evans
authors: School of Electronic and Electrical Engineering, University of Leeds, Leeds, UK.
authors: Steven
authors: S
authors: Freear
mesh_terms: D003287:Contrast Media; D008081:Liposomes; D045423:Microbubbles; D000069453:Ultrasonic Waves
chemical_list: D003287:Contrast Media; D008081:Liposomes
keywords: Drug delivery; Liposomes; Microbubbles; Microfluidics; Subharmonic imaging; Ultrasound contrast agents