Gastric-mucus penetrating and responsive microgels for alleviating Helicobacter pylori-induced gastritis

Helicobacter pylori (H. pylori) is a prevalent global pathogen responsible for gastritis and the potential development of gastric cancer. Sulforaphane (SFN), a foodborne compound, exhibits notable antibiotic properties against H. pylori. However, its utility is limited by poor stability and susceptibility to environmental degradation. Here, we developed a gastric-responsive-release microgel for delivering anti-H. pylori SFN. The microgels were prepared by cross-linking α-lactalbumin nanotubes then coated with chitosan (CTS-MGs). SFN was loaded into microgels with a loading rate of 10.73 ± 0.25 %. The CTS-MG showed a strong adhesion to the gastric mucosa, prolonging gastric retention for up to 24 h and responsively releasing SFN in the stomach. Furthermore, CTS-MG/SFN dissociated and released nanotubes/SFN, which could penetrate into the gastric mucus layer and arrive at the deepest mucus sites where most H. pylori were colonized. Our results revealed that CTS-MG/SFN displayed an obvious inhibitory effect against H. pylori. The oral administration of CTS-MG/SFN in H. pylori-infected mice effectively alleviated H. pylori-induced gastritis and modulated gastric microbiota homeostasis. This work demonstrated high potential of CTS-MG microgels for gastric-targeted and oral delivery of antibiotic natural compounds against H. pylori infection.