CD274 and colitis: Histopathological evaluation showed that DSS-induced colitis mice exhibited notable damage to the colon structure with epithelial disruption, loss of goblet cells, and significant infiltration of inflammatory cells, whereas the administration of PD-L1-Fc, PD-L1-Fc/PLGA nanoparticles or PD-L1-Fc/Oxi-αCD nanoparticles alleviated histological colonic damage, as shown by the repaired colonic mucosal epithelium, increased goblet cell frequency, and reduced inflammatory cell infiltration in the mucosa and submucosa (Fig. 3H and Supplementary Fig. 12E).