Chitosan-modified Phellinus igniarius polysaccharide PLGA nanoparticles ameliorated inflammatory bowel disease.

In many clinical studies, prebiotics have been used as adjuvant therapy for inflammatory bowel disease (IBD). Phellinus igniarius polysaccharide (PIP) possesses great anti-inflammatory and prebiotic activities. Herein, we developed an orally deliverable PIP-loaded chitosan-modified PLGA nanomedicine (CS-PIPP) to investigate its anti-inflammatory effect in vitro and in vivo. Dextran sodium sulfate (DSS)-induced colitis model was established to evaluate the preventive effect of CS-PIPP on IBD. This study characterized that CS-PIPP had a size of 288.7 ± 5.49 nm, positive zeta potential, and showed good stability over four weeks. The in-vitro study suggested that CS-PIPP had enhanced phagocytosis by macrophages, which could further significantly inhibit M1-like macrophages phenotype and regulate lipopolysaccharide (LPS)-induced inflammatory cytokines. The in-vivo study revealed that CS-PIPP prominently prevented intestinal inflammatory damage and protected the integrity of the intestinal barrier. Moreover, CS-PIPP increased the contents of short-chain fatty acids (SCFAs) and positively regulated the gut microbiota. Specifically, CS-PIPP reduced enteropathogenic microorganisms while increasing the beneficial microbiota, including Lactobacillus and Akkermansia, which revealed the potential of CS-PIPP as prebiotics. Generally, CS-PIPP promoted the anti-inflammatory effect of PIP, so it could be regarded as a novel and potent nanoformulation to treat IBD.