Living Probiotics-Loaded Hydrogel Microspheres with Gastric Acid Resistance and ROS Triggered Release for Potential Therapy of Inflammatory Bowel Disease

Probiotics have played a critical role in regulating intestinal flora balance and have been considered as an effective and safe strategy for treating inflammatory bowel disease (IBD). However, it is still a huge challenge to precisely deliver probiotics to the inflammatory area while maintaining their high activity. Herein, a well-designed strategy is provided to construct hydrogel microspheres (HMs) through microencapsulation for loading living probiotics, which realizes a high encapsulation efficiency of 95.24%. By chemically cross-linking with 1,4-phenylenediboronic acid (Pa), the microspheres present a sensitive reactive oxygen species (ROS) response for targeted delivery and controlled release of the probiotics. In vitro simulated experiments demonstrate the high viability of the encapsulated probiotics against the simulated gastric (>1 × 104 CFU/mL) and intestinal (>2 × 107 CFU/mL) fluid environments, which are higher than the data (0 and 1 × 107 CFU/mL) of the free cells, respectively. Moreover, the microspheres exhibited nontoxicity and favorable biodegradability, ensuring their safe use in vivo. This work provides a universal and viable alternative to precisely deliver highly active probiotics to intestinal inflammatory areas, promising to meet the needs of targeted IBD therapy.