Effect of ultrasound on the distribution of nanoparticles in tumor tissue

Abstract

PC-3 prostate adenocarcinoma cells were injected subcutaneously in the hind leg of female Balb/c nude mice. After a few weeks of tumor growth, 200 $\mu$L of a solution containing gas bubbles stabilized by PBCA nanoparticles encapsulating nile red was intravenously administered. The mice were then divided into four treatment groups, three of which were treated with ultrasound, while the last group was not. The three different ultrasound treatments were (1) 1 MHz and MI = 0.1, (2) 1 MHz and MI = 0.4, and (3) 1 MHz and MI = 0.4 + 5 MHz and MI = 2.24. Blood vessels were stained using FITC-lectin. Freeze sections from the tumors were prepared and imaged in a confocal microscope. The images were quantitatively and qualitatively analyzed. No statistical difference was found between the different treatment groups from the quantitative analysis, as the standard deviations were too large. However, a qualitative difference could be observed between mice that were not treated with ultrasound and mice that were treated. It was concluded that the uptake in adipose tissue seemed to be improved after ultrasound.