Figure 4.

SN38 delivery with US-triggered therapeutic microbubbles significantly inhibits tumor growth. (A) Abbreviated nomenclature and treatment groups subsequently denoted in brackets used are shown (n = number of mice per group). (B) A schematic of the experimental plan is shown with each treatment (Tx, 0.4 mg/kg SN38) and 3D high frequency ultrasound (HF-US) imaging denoted. The mean (± SEM) starting tumor volumes for each group were 100 (± 13.2) mm³ for vehicle +T and 106 (± 16.6) mm³ for the thMBs +T group which were not statistically significantly different at this time point. (C) The mean (± SEM) ratio to day 0 tumor volume measured by 3D HF-US is shown. Unpaired Mann-Whitney test *¹ p = 0.048, *² p = 0.0159. (D - E) Final day tumor mass was measured and tumor doubling time calculated (negative tumor doubling times indicate tumor regression). The median value for each group is denoted by a line (neither statistically significantly different). (F - G) Apoptosis and double-strand breaks, the median (+ range) value for each group are denoted. Apoptosis p = 0.0159 and double-strand breaks p = 0.0317, unpaired Mann-Whitney test. (H) Biodistribution of SN38 within all tissues 72 h post final treatment. No SN38G was detected.