Enhanced Antitumor Efficacy and Reduced Cardiotoxicity of Ultrasound-Mediated Doxorubicin Delivery by Microbubble-Liposome Complexes

Figures

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  Figure 1.. In vivo mouse tumor treatments. (a) Dox-containing formulations used in the tumor growth inhibition study: in each treatment 1.7 × 108 LDox + MB, DoxLPX, or LDox (equivalent dose of 100 μg Dox), or 100 μg free Dox was injected. ELPX (1.7 × 108) and saline were used as controls; (b) Schematic diagram depicting the intravenous infusion through the jugular vein and concurrent UTMC treatments (4 times) during infusion. Echocardiographic imaging was performed every 7 days.

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  Figure 2.. Characterization of DoxLPX. (a) Schematic structure of DoxLPX; (b) Brightfield and fluorescence microscopic images of DoxLPX (40 ×); (c) Size distribution of MB and DoxLPX; (d) In vitro Dox release kinetics from DoxLPX exposed to 3 different US pulses in vitro.

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  Figure 3.. DoxLPX + UTMC has superior efficacy against MCA205 tumor. (a) Tumor growth plots (normalized to tumor size on Day 0). (b) Kaplan-Meier survival curves. n = 8–9 mice per group. See also Table 2.

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  Figure 4.. DoxLPX + UTMC preserves cardiac function. Serial echocardiographic data up to day 21, showing average (a) EF, ejection fraction; (b) FS, fractional shortening; and (c) LV mass index. Data are normalized to Day 0 values. n = 8–9 mice per group. *p < 0.05, **p < 0.01 vs. Day 0 data.

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  Figure 5.. DoxLPX + UTMC protects against Dox-induced fibrosis. (a) Representative cardiac sections stained with Sirius red/fast green to detect interstitial fibrosis. Red: collagen fibrosis; Green: non-collagen components. (b) Quantification of fibrosis area in heart tissue by morphometry in ventricular cross-sections. n = 8–9 mice per group, data shown as mean ± SD.

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  Figure 6.. Caspase-3 activity in heart tissue homogenates. Free Dox caused more apoptosis (Caspase-3 activity) vs. other treatments. n = 8–9 mice per group, *p < 0.05, **p < 0.01.

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  Figure 7.. Representative ex vivo fluorescence images showing biodistribution of Dox analog (Cy5.5). (a) Representative ex vivo fluorescence images of organs excised 3.5 hrs after treatment, demonstrating higher intra-tumoral and lower cardiac uptake of Cy5.5 after Cy5.5LPX + UTMC (third panel from left); (b) Quantitative biodistribution (n = 3) of Cy5.5 concentration in tumor, blood, heart, and lung in tumor-bearing mice 3.5 h post i.v. injection of free Cy5.5, LCy5.5, LCy5.5 + MB + UTMC, and Cy5.5 LPX + UTMC; (c) Cy5.5 concentration ratio in tumor/heart tissue (n = 3 each group). *p < 0.05, **p < 0.01, ***p < 0.001.