Figure 3
US-triggered release of HPPH post-loaded cationic PAA-NMe3+ nanoparticles was determined in 1% HSA-PBS. The HPPH (ε: 47,500 L/mol/cm at 661 nm) dispersed at a concentration of 20 μM in 1% HSA-PBS solution was irradiated with US at a dose of 0.5 W/cm2, 3.3 MHz at 5, 10 and 20 min. At each time point, the solution was filtered through a 100 KDa centrifuge filter. The concentration of HPPH in filtrates was determined spectrophotometrically, and the release of HPPH was plotted against time.
