The construction of self-protective ferritin nanocage to cross dynamic gastrointestinal barriers with improved delivery efficiency

Ferritin nanocages are promising nanocarriers for food bioactive compound delivery, but gastrointestinal barriers including disassociation by environmental acidity, degradation by protease, pose great challenges for cargo delivery. Herein, a self-protective ferritin that can cross gastrointestinal barriers is prepared through phosphorylation modification at 37 °C for 4 h. The results showed that the conjugation of phosphate group facilitates an acidic pI shift of ferritin from ∼5.0 to ∼4.0, allowing fast aggregation and precipitation in an intact spherical form rather than disassociation into subunits in acidic environments. Meanwhile, after incubation at simulated gastric juice for 30 min, almost 80 % STP-MjFer is retained, thus, the aggregation state and phosphate layers can improve its digestive stability. Besides, curcumin can be encapsulated within its cavity and the retention rate is ∼ 9 times higher than that of MjFer nanocage in simulated gastrointestinal fluid. Overall, the self-protective ferritin nanocarrier displays great potential for cargo delivery in food science.