The main goal of this long term collaborative research consists in the development of methods for monitoring and enhancing cavitation activity in pulsed High Intensity Focused Ultrasound fields (HIFU cavitation). The influence of a short-time action of a low-frequency ultrasound on the sonoluminescence generation by a high frequency pulsed field has been found to consist in a remarkable lowering of the cavitation thresholds and in an increase of the sonoluminescence intensity. The stimulating effect of the low-frequency field depends on its duration and on the intensities of both fields. Possible mechanisms of this effect have been discussed. It has been shown that pulsed modulation of an ultrasound field is an effective tool for controlling both the cavitation activity and the dynamics of the development of the cavitation zone in high intensity focused ultrasound fields. Following these innovative lines of research, the first part of the cooperation was mainly devoted to the basic physical understanding and to technological applications. As a result, ultrasonic intensification of physical and chemical processes in liquids is now widely used. More recently it was found that cavitation is also a key factor in many biological and medical applications of power ultrasound. Applications of high intensity focused ultrasound in experimental and clinical therapies has indeed received in last years increased attention. This interest is motivated by observations and promising results in the study of ultrasonically induced biological effects such as DNA mediated transport of medicines, thermal lesion, delivery of small compounds, macromolecules and other therapeutic compounds into cell suspensions and protein in tissues. It is believed that cavitation plays an important role in these bioeffects, some of which being caused by bubbles pulsation and implosions. In this paper, we will present some recent results of the joint research aimed at clarifying the dynamics of the HIFU Cavitation zone development and its applications to enhancement of pharmacological effectiveness.
Cavitation in high intensity focused ultrasound fields for biological and medical applications
FRANCESCUTTO, ALBERTO;
2011-01-01
Abstract
The main goal of this long term collaborative research consists in the development of methods for monitoring and enhancing cavitation activity in pulsed High Intensity Focused Ultrasound fields (HIFU cavitation). The influence of a short-time action of a low-frequency ultrasound on the sonoluminescence generation by a high frequency pulsed field has been found to consist in a remarkable lowering of the cavitation thresholds and in an increase of the sonoluminescence intensity. The stimulating effect of the low-frequency field depends on its duration and on the intensities of both fields. Possible mechanisms of this effect have been discussed. It has been shown that pulsed modulation of an ultrasound field is an effective tool for controlling both the cavitation activity and the dynamics of the development of the cavitation zone in high intensity focused ultrasound fields. Following these innovative lines of research, the first part of the cooperation was mainly devoted to the basic physical understanding and to technological applications. As a result, ultrasonic intensification of physical and chemical processes in liquids is now widely used. More recently it was found that cavitation is also a key factor in many biological and medical applications of power ultrasound. Applications of high intensity focused ultrasound in experimental and clinical therapies has indeed received in last years increased attention. This interest is motivated by observations and promising results in the study of ultrasonically induced biological effects such as DNA mediated transport of medicines, thermal lesion, delivery of small compounds, macromolecules and other therapeutic compounds into cell suspensions and protein in tissues. It is believed that cavitation plays an important role in these bioeffects, some of which being caused by bubbles pulsation and implosions. In this paper, we will present some recent results of the joint research aimed at clarifying the dynamics of the HIFU Cavitation zone development and its applications to enhancement of pharmacological effectiveness.Pubblicazioni consigliate
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