Special issue on microbubbles: from contrast enhancement to cancer therapy

Abstract

The clinical use of microbubbles originated with the fortuitous discovery by Joyner that intravenous injection of certain liquids produced contrast enhancement in ultrasound images [3]. Subsequent investigation revealed that it was not the liquids themselves which were responsible for the observed effect, but rather the presence of gas microbubbles either suspended in the liquid or formed at the tip of the catheter through which it was being injected. Since then, the use of microbubbles in diagnostic and, more recently, therapeutic applications has become a rapidly expanding field of research. The aim of this special issue is to provide an up-to-date overview of the developments in the physics, engineering and clinical applications of microbubbles.Microbubble ultrasound contrast agents have now been in clinical use for more than two decades and their evolving applications are discussed in detail in the comprehensive review by Cosgrove and Harvey [1] who have extensive clinical experience in this area. The primary application of microbubbles is in echocardiography, for ventricular opacification and delineation of endocardial borders. They have also been used successfully for the assessment of systolic function and left ventricular volume, and for identifying myocardial infarction and coronary artery stenoses. As explained in the paper, they are moreover becoming rapidly accepted for the detection, characterisation and image guided treatment of focal liver lesions.

Perfluoroalkylated poly(oxyethylene) thiols: Synthesis, adsorption dynamics and surface activity at the air/water interface, and bubble stabilization behaviour

“…Microbubbles have raised interest in the last decades owing to their potential as contrast agents for ultrasound diagnosis, as drug/ gene delivery systems and as mechanical intravascular tools [22][23][24][25][26][27]. In consequence, the physical chemistry of such bubbles, and in particular the properties of their shells with regards to microbubbles' basic attributes such as size and stability control [28][29][30][31], viscosity [9,32], resonance intensity and frequency [33], capacity to generate sound harmonics [34][35][36], to enable gene transfer [27,37] and to undergo ultrasound-triggered disruption [38], have been investigated.…”

Safety and bio-effects of ultrasound contrast agents

“…The behaviour of ultrasound contrast agents (UCAs) in an ultrasound field has been extensively reviewed and will not be re-iterated here [54,60]. Instead we will concentrate on the biological consequences of such bubble activity, drawing on published literature for examples.…”

Honey, I shrunk the bubbles: microfluidic vacuum shrinkage of lipid-stabilized microbubbles

“…[5][6][7] Ultrasound and microbubbles have also been utilized for therapeutics such as in enhancing gene and drug delivery. 8,9 Delivery occurs through pores on the membrane of tumor cells to lyse the cells or selectively deliver genes and/or drugs for cancer treatment [10][11][12] and enhanced endocytosis. 13 The acoustic response of microbubbles depends on the microbubbles' characterstics such as their size and shell-type, in addition to the degree of ultrasound exposure.…”