Figure 4.

(a) The release profiles of PTX from MSN and DESN in PBS at pH 7.4; (b) the release profiles of PTX from DESN under LEUS with different intensities (1 MHz; 0, 0.4, 0.6, 0.8, and 1.0 W·cm⁻²). The existence of β-CD had a certain effect on PTX encapsulation, and the release rate of PTX was getting faster with the increasing of ultrasonic intensity. PTX cumulative release amount from DESN was about 21.48%, 31.01%, 76.76%, and 90.38% under ultrasonic intensities 0.4 W·cm⁻², 0.6 W·cm⁻², 0.8 W·cm⁻², and 1.0 W·cm⁻² after 60 min, respectively.