Comparison between xanthene and Albunex on producing sonodynamic tissue damage

The authors' recent in vitro and in vivo experiments demonstrated that sonodynamically active cavitation was induced at low ultrasonic intensity in the presence of a certain chemical agent especially when the second harmonic was superimposed onto the fundamental. Chemical agents such as xanthene derivatives were found to be extremely effective. It has also been reported that microbubble contrast agents such as Albunex can enhance in vivo as well as in vitro cavitation. The effects of Albunex and erythrosin on the intensity threshold for cavitationally producing focal damage in murine liver tissue are compared and examined in a progressive wave mode. Albunex reduced the intensity threshold by orders of magnitude even in the case of single frequency insonation. Second-harmonic superimposition (SHS) did not significantly change the threshold with Albunex. Erythrosin and its derivative were quite effective to reduced the intensity threshold especially in combination with SHS at the second-harmonic phase emphasizing the peak rarefaction. The observed difference between the effects of Albunex and erythrosin in combination with SHS is consistent with the hypothesis that SHS enhances cavitational effects through accelerating the growth of microbubbles rather than their collapse.