Fig. 5. Model fits of Dox release profiles from ZIF8–Dox and ZIF8–Dox@PAA in PBS at 37 °C (A) at pH 7.4 and (B) at pH 4; (C) illustration of release stages for ZIF8–Dox at pH 4.0; and (D) release processing mechanism of Dox from ZIF8–Dox@PAA with decreasing pH from 7.4 to 4.0 in PBS solution. Abbreviations: Dox, doxorubicin; PAA, polyacrylic acid; PBS, phosphate-buffered saline; ZIF8, zeolite imidazolate framework-8.
