Examination of Inertial Cavitation of Optison in Producing Sonoporation of Chinese Hamster Ovary Cells

Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Ultrasound in medicine & biology (Impact Factor: 2.21). 08/2008; 34(12):2009-18. DOI: 10.1016/j.ultrasmedbio.2008.05.003
Source: PubMed


The objective of this project was to elucidate the relationship between ultrasound contrast agents (UCAs) and sonoporation. Sonoporation is an ultrasound-induced, transient cell membrane permeability change that allows for the uptake of normally impermeable macromolecules. Specifically, this study will determine the role that inertial cavitation plays in eliciting sonoporation. The inertial cavitation thresholds of the UCA, Optison, are compared directly with the results of sonoporation to determine the involvement of inertial cavitation in sonoporation. Chinese hamster ovary (CHO) cells were exposed as a monolayer in a solution of Optison, 500,000 Da fluorescein isothiocyanate-dextran (FITC-dextran), and phosphate-buffered saline (PBS) to 30 s of pulsed ultrasound at 3.15-MHz center frequency, 5-cycle pulse duration and 10-Hz pulse repetition frequency. The peak rarefactional pressure (P(r)) was varied over a range from 120 kPa-3.5 MPa, and five independent replicates were performed at each pressure. As the P(r) was increased, from 120 kPa-3.5 MPa, the fraction of sonoporated cells among the total viable population increased from 0.63-10.21%, with the maximum occurring at 2.4 MPa. The inertial cavitation threshold for Optison at these exposure conditions has previously been shown to be in the range 0.77-0.83 MPa, at which sonoporation activity was found to be 50% of its maximum level. Furthermore, significant sonoporation activity was observed at pressure levels below the threshold for inertial cavitation of Optison. Above 2.4 MPa, a significant drop in sonoporation activity occurred, corresponding to pressures where >95% of the Optison was collapsing. These results demonstrate that sonoporation is not directly a result of inertial cavitation of the UCA, rather that the effect is related to linear and/or nonlinear oscillation of the UCA occurring at pressure levels below the inertial cavitation threshold.

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Available from: Ryan Lawrence Steinberg, May 14, 2015
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    • "In this framework, microscopic and spectroscopic techniques offer the sensitivity and capability to detect morphological, structural and functional fine alterations of sonicated cells, as they are not yet significantly advanced [22] [23] [24] [25] [26] [27]. In previous papers [28] [29], we have shown how the effects of US on biological samples can be effectively revealed by means of Fourier Transform Infrared (FTIR) spectroscopy, a non-destructive technique which is able to monitor conformational and functional changes exhibited by specific subsets of macromolecules inside a cell population. "
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