Perfluorohexane-encapsulated fullerene nanospheres for dual-modality US/CT imaging and synergistic high-intensity focused ultrasound ablation

Figures & data

Figure 1 (A, B) SEM images of prepared PFH-C₆₀ composite nanospheres at different magnifications; (C) hydrolyzed particle size distributions of PFH-C₆₀ composite nanospheres based on DLS measurements.

Abbreviations: SEM, scanning electron microscope; C₆₀, fullerene; PFH, perfluorohexane; DLS, dynamic light scattering.

Figure 2 Ex vitro evaluations of the efficiencies of the same irradiation powers and time durations for ultrasound imaging under different groups [NS (A); C₆₀ solutions (B); PFH-C₆₀ solutions (C); left images: before irradiation, right images: after irradiation]. (D) Corresponding gray values of the interest region (each column is the average of three data points).

Abbreviations: NS, normal saline; C₆₀, fullerene; PFH, perfluorohexane.

Figure 3 In vitro CT image (A) and CT value (B) of the different groups [(a) C₆₀-NS (C₆₀: 4.0 mg/mL); (b) pure PFH; (c–f) PFH-C₆₀ nanosphere solution: (c) C₆₀: 4.0 mg/mL; (d) C₆₀: 3.0 mg/mL; (e) C₆₀: 2.0 mg/mL; (f) C₆₀: 1.0 mg/mL].

Abbreviations: NS, normal saline; C₆₀, fullerene; PFH, perfluorohexane; CT, computed tomography.

Figure 4 (A) Gray color of unirradiated C₆₀ solution; (B) dark brown color of PFH-C₆₀ (C₆₀ 8.0 mg/mL) solution after irradiation; (C) brown color of PFH-C₆₀ (C₆₀ 4.0 mg/mL) solution after irradiation; (D) light brown color of C₆₀ (8.0 mg/mL) solution after irradiation (B, C: HIFU irradiation: 200 W/9 seconds; D: HIFU irradiation: 300 W/9 seconds).

Abbreviations: C₆₀, fullerene; PFH, perfluorohexane; HIFU, high-intensity focused ultrasound.

Figure 5 (A) Ex vivo evaluation of the efficiency of ultrasound imaging and HIFU therapy under the same irradiation power and duration (200 W for 9 seconds) for these three groups after intra-tissue injection of solutions and HIFU exposure of bovine livers (NS (a); C₆₀ (b); PFH-C₆₀ (c); left images: before irradiation; right images: after irradiation). (B) Digital photos of ablated bovine livers (NS (a); C₆₀ (b); PFH-C₆₀ (c)). (C–E) Corresponding necrotic volume, gray areas, and gray value (each column is the average of three data points).

Note: *Significant differences between comparing PFH-C₆₀ and C₆₀, or the NS control at P≤0.01, respectively.

Abbreviations: NS, normal saline; C₆₀, fullerene; PFH, perfluorohexane; HIFU, high-intensity focused ultrasound.

Figure 6 (A) HIFU + NS group: the mitochondria (red arrow) and endoplasmic reticulum (green arrow) were slightly distended; (B) HIFU + C₆₀ groups: cell membranes (red arrow) were lightly interrupted, a few deposits of C₆₀ (green arrow) were observed in the cytoplasm, and a clear nuclear membrane (blue arrow) was still observed; (C) HIFU + PFH-C₆₀ group: most cell membranes (red arrow) and nuclear membranes (blue arrow) were almost interrupted or undefined, several deposits of C₆₀ (green arrow) were observed in the cytoplasm around the nuclear membranes.

Abbreviations: NS, normal saline; C₆₀, fullerene; PFH, perfluorohexane; HIFU, high-intensity focused ultrasound.

Scheme 1 Schematic illustration of the formulation process for PFH-C₆₀ nanospheres and HIFU ablation principles.

Abbreviations: C₆₀, fullerene; PFH, Perfluorohexane; ROS, reactive oxygen species; ADV, acoustic droplet vaporization; ∆T, temperature variation.