Medical ultrasound has shown great potential as a minimally invasive therapy technique. It can be used in areas such as histotripsy, thermal ablation, and administering medication. The success of these therapies is improved by the cavitation of microbubbles. This study evaluated the effect of varying the pressure amplitude on cavitation resonance frequency and the corresponding bubble size at t...

Sonoporation has been associated with drug delivery across cell membranes and into target cells, yet several limitations have prohibited further advancement of this technology. Higher delivery rates were associated with increased cellular death, thus implying a safety-efficacy trade-off. Meanwhile, there has been no reported study of safe in vitro sonoporation in a physiologically relevant flow...

One of the earliest events in cellular mechanotransduction is often an increase in intracellular calcium concentration associated with intracellular calcium waves (ICWs) in various physiologic or pathophysiologic processes. Although cavitation-induced calcium responses are believed to be important for modulating downstream bioeffects such as cell injury and mechanotransduction in ultrasound the...

Introduction When a liquid is irradiated with high-intensity and low-frequency ultrasound, acoustic cavitation occurs and there are some methods to determine and quantify this phenomenon. The existing methods for performing these experiments include sonochemiluminescence (SCL) and chemical dosimetric methods. The particles in a liquid decrease the ultrasonic intensity threshold needed for cavit...

We use focused ultrasound bursts to submit a liquid to mechanical tension. When the pressure in the sound wave reaches a sufficiently low value, vapor bubbles are nucleated in the bulk liquid. According to nucleation theory, increasing the ultrasound frequency increases the cavitation threshold by a calculable amount. To check this, we have built a fiber optic probe hydrophone based on one orig...

Sonoporation has been exploited as a promising nonviral strategy for intracellular delivery of drugs and genes. The technique utilizes ultrasound application, often facilitated by the presence of microbubbles, to generate transient, nonspecific pores on the cell membrane. However, due to the complexity and transient nature of ultrasound-mediated bubble interaction with cells, no direct correlat...

An •mo•b•, Hartmanindia •astdlanii, which possesses many features typical of higher-order animal cells, was irradiated with 1-MHz ultrasound while suspended inordinary growth medium and in one with increased viscosity. The ultrasonically produced cavitation was monitored and a strong correlation is found between the number of discrete cavitation events occurring and the decrease in cell number%...

Cavitation often occurs in therapeutic applications of medical ultrasound such as shock-wave lithotripsy (SWL) and high-intensity focused ultrasound (HIFU). Because cavitation bubbles can affect an intended treatment, it is important to understand the dynamics of bubbles in this context. The relevant context includes very high acoustic pressures and frequencies as well as elevated temperatures....

Variation in intensity of scattered light from cavitation bubbles in an ultrasonic standing wave field at different contents of dissolved air is studied experimentally. The number of cavitation bubbles that repeat expansion and contraction correlates with the sonochemical reaction yield and the evaluation of the number of bubbles is important for perspective on the yield. Peak-to-peak of intens...

We have simulated effects of a shock wave in water that would result from the collapse of a cavitation bubble on binding in model complexes. We have considered a benzene dimer, a pair of uracil molecules, a complex of fragments of the X-linked inhibitor of apoptosis and caspase-9, and a fragment of c-Myc oncoprotein in binding with its dimerization partner Max. The effect of the shock waves was...