Targeted Dual-Responsive Probiotic Microspheres for Sequential Protection, Adhesion, and On-Demand Release in Ulcerative Colitis Therapy

Oral probiotics show promise for inflammatory bowel disease but are limited by poor gastrointestinal viability, targeting, and colonization. We developed a multi-targeting probiotic composite microsphere (PCM) via scalable solution blow-spinning, with >20-fold higher throughput than electrospinning. PCMs provide three key functions: (1) pH-triggered probiotic protection: PCMs contract in gastric acid, shielding probiotics and increasing survival 2162-fold over free probiotics; (2) charge-mediated adhesion: negatively charged microspheres adhere to positively charged mucin overexpressed at inflamed colonic lesions; and (3) enzyme-triggered release: overexpressed hyaluronidase degrades hyaluronic acid, releasing viable bacteria via the "Trojan horse" mechanism. This sequential mechanism ensures high local probiotic density at inflamed sites. In DSS-induced mouse colitis, PCMs outperformed 5-aminosalicylic acid in alleviating inflammation, repairing the mucosal barrier, and restoring microbial homeostasis. 16S rRNA sequencing showed selective enrichment of beneficial genera and suppression of inflammation-associated pathobionts. This scalable, multi-responsive platform offers next-generation oral therapy for IBD and microbiome-associated gastrointestinal diseases.