Fig. 1
a FESEM and b TEM images of DIS NPs and COM NPs. c Loading efficiencies and d Dh values of DIS NPs, COM NPs and COM-1 NPs (without casein) before and after lyophilization then re-dispersion; Dh values of the re-dispersed e DIS NPs and f COM NPs after lyophilization and storage at − 20, 2–8 and 25 °C for different periods. gIn vitro EXE releases from DIS NPs and COM NPs in pH 2.0 HCl solution (0–2 h) and pH 7.4 PBS solution (2–48 h). Residual EXE of free EXE, EXE/PC/CA Complex, DIS NPs and COM NPs samples after incubations in h pepsin solution at pH 2.0 and i pancreatin solution at pH 7.4, *P < 0.05 compared with free EXE. (n = 3)