FIGURE 8.

Illustration of pH-triggered self-unpacking capsule containing Ex@MIL101@Gel ± nanoparticles for oral Exendin-4 delivery. The hydrogel-coated MOF nanoparticles containing Exendin-4 were obtained by free radical copolymerization of acryloyl-modified NH2-MIL101 nanoparticles, NIPAM, and MPDMSA, with GDA as a crosslinker. The capsules protect the peptide-loaded nanoparticles from the stomach’s acidic environment and unpack them in the intestine, generating CO₂ bubbles to promote the movement of nanoparticles. The zwitterionic surface of the nanoparticles further helps the transportation across the epithelial layer of the intestine (Zhou Y. et al., 2021). Copyright^© 2020, Weily.