Fig. 2

pH responsiveness and bone targeting properties of the nanoplatform OAPLG. (a) Following incubation with DiD-labeled OAPLG at pH 7.4, the fluorescence signal of DiD on the surface of the bone slice was assessed at time intervals of 1 min, 1 day, 3 days, and 7 days. Subsequently, the pH was rapidly adjusted to 4.5, and the DiD fluorescence signal was measured at intervals of 1 min, 3 min, and 5 min. (b) Drug release curves of OAPLG in different pH buffer solutions over time. (c) Detection of pH value in OAPLG titration of different pH buffer solutions. (d) Fluorescence signals in live as well as isolated organs and femur and tibia of mice 4 and 8 h after intravenous injection of DiD-labeled OAPLG.(e) Quantification of fluorescence signals in femur and tibia 4 h after intravenous injection of DiD-labeled OAPLG. (f) Quantification of fluorescence signals in femur and tibia 8 h after intravenous injection of DiD-labeled OAPLG. n = 3. *P < 0.05, **P < 0.01, ***P < 0.001