Figure 1.

a) Schematic representation of ultrasound contrast agent preparation. b) Schematic of acoustic cavitation initiation by the PL-hMSN under HIFU insonation. c) Normalized ultrasound contrast intensities calculated from the acquired movies of agarose samples containing MSN or PL-hMSN at different concentrations, which were exposed to HIFU for 15 s at a pulse duration of 16.8 μs, a pulse repetition frequency of 10 Hz (duty cycle of 0.017%), and a peak negative pressure of 16.8 MPa. Insets are the representative images taken from movies acquired during HIFU irradiation in the presence or absence of nanoparticles (200 μg mL⁻¹). Red circles indicate the region of interest in the images. d) Normalized ultrasound contrast intensity calculated from the three acquired movies of agarose samples containing PL-hMSN at 200 μg mL⁻¹, which were exposed to HIFU for 10 min at a pulse duration of 16.8 μs, a pulse repetition frequency of 10 Hz (duty cycle of 0.017%), and peak negative pressure of 16.8 MPa. Error bars = 1 SD, studies were run in triplicate.