High-Speed <italic>In Situ</italic> Observation System for Sonoporation of Cells With Size- and Position-Controlled Microbubbles

Abstract

Abstract-A high-speed in situ microscopic observation system developed for basic studies on mechanisms of sonoporation is introduced in this paper. The main part of the system is an inverted-type fluorescence microscope, and a high-speed camera of 20 MHz in maximum framing rate was used to visualize dynamics of cavitation bubbles that causes a sonoporation effect. Differential interference contrast and fluorescence techniques were used for sensitive visualization of cell changes during sonoporation. The system is also equipped with optical tweezers that can move a microbubble of several microns in size by using a donut-shaped light beam. In situ microscopic observation of sonoporation was carried out using a cell with a size-and position-controlled microbubble. The experimental results showed that the ability of cells to repair sonoporation-induced damage depends on their membrane tension, indicating the usefulness of the observation system as a basic tool for investigation of sonoporation phenomena.

Ultrasound-Responsive Cavitation Nuclei for Therapy and Drug Delivery

“…1. Direct impingement: Even at moderate amplitudes of oscillation, the acceleration of the bubble wall may be sufficient to impose significant forces on nearby surfaces, easily deforming fragile structures such as biological cell membranes (van Wamel et al 2006;Kudo 2017) and blood vessel walls (Chen et al 2011). 2.…”

Cellular Bioeffect Investigations on Low-Intensity Pulsed Ultrasound and Sonoporation: Platform Design and Flow Cytometry Protocol

“…Of particular importance is the proper design of an acoustic exposure platform whose in situ ultrasound field pressure and various intensity measures are well characterized as stipulated in bioeffect experiment reporting guidelines [19]. Based on this premise, acoustically coupled live cell imaging platforms have been constructed to gain insight into cellular morphology changes during ultrasound pulsing [20], [21] and acoustic cavitation [22]- [24]. Fluorescent and confocal imaging modes of these platforms have also been used to observe sonoporationinduced cytostructural remodeling [25], [26], intercellular interactions [27], calcium ion influx [28]- [30], transmembrane depolarization [31], and reactive oxygen species changes [32].…”

Ultrasound homogenises suspensions of hydrophobic particles

“…10 During camera recording, the materials were subjected to ultrasound pulses, each consisting of 3 cycles with a centre transmitting frequency of 1 MHz and a peak-negative pressure of 200 kPa, from a laboratoryassembled single-element transducer. 9,10 The signal fed into the transducer was generated by an AFG320 arbitrary function generator (Sony-Tektronix, Shinagawa-ku, Tokyo, Japan) and amplified by a UOD-WB-1000 wide-band power amplifier (TOKIN Corporation, Shiroishi, Miyagi, Japan).…”