Microbubbles and ultrasound: from diagnosis to therapy

Abstract

The development of ultrasound contrast agents, containing encapsulated microbubbles, has increased the possibilities for diagnostic imaging. Ultrasound contrast agents are currently used to enhance left ventricular opacification, increase Doppler signal intensity, and in myocardial perfusion imaging. Diagnostic imaging with contrast agents is performed with low acoustic pressure using non-linear reflection of ultrasound waves by microbubbles. Ultrasound causes bubble destruction, which lowers the threshold for cavitation, resulting in microstreaming and increased permeability of cell membranes. Interestingly, this mechanism can be used for delivery of drugs or genes into tissue. Microbubbles have been shown to be capable of carrying drugs and genes, and destruction of the bubbles will result in local release of their contents. Recent studies demonstrated the potential of microbubbles and ultrasound in thrombolysis. In this article, we will review the recent advances of microbubbles as a vehicle for delivery of drugs and genes, and discuss possible therapeutic applications in thrombolysis.

Biomedical photoacoustics beyond thermal expansion using triggered nanodroplet vaporization for contrast-enhanced imaging

“…and release 24 , vessel occlusion 26,38 and cell membrane sonoporation effects from vaporization 50 .…”

Ultrasound microbubble contrast agent-mediated suicide gene transfection in the treatment of hepatic cancer

“…Ultrasound has been applied in gene therapy and in recent years, an ultrasound contrast agent has been identified as an adjuvant to increase the efficiency of ultrasound-mediated gene transfection. The application of ultrasound treatment and an ultrasound contrast agent for gene transfection is a more favorable strategy for gene therapy, as it has a high safety potential and the ability to directly target cells (3,4). In this study, we constructed eukaryotic expression vectors expressing the thymidine kinase (TK) gene, which contained either the AFP promoter (specific in hepatic cancer cells) or the kinase insert domain receptor (KDR) promoter (specific in vascular endothelial cells).…”

Ultrasound-targeted microbubble destruction enhances AAV-mediated gene transfection in human RPE cells in vitro and rat retina in vivo

“…Sonoporation, which can transiently enhance the permeability of cell membranes to introduce genes into cells by exposing them to US, is considered to have a key role, and MBs acting as cavitation nuclei can effectively focus US energy and further potentiate bioeffects. [8][9][10][11] Recent reports show that US/MBs can be used safely and efficiently in many models of diseases in various organs. 12 As far as we know, in the sphere of ophthalmology, scholars pay much attention to study US-mediated transfection (USMT) or UTMD on the cornea, [13][14][15][16][17] but few report on the retina.…”