Fig. 4

Anti-colitis treatment of the CS-PLGA NPs. A Schematic diagram of DSS-induced colitis and treatment regimen. B Drug treatment alleviated the shrinkage of colon length. C Images of the colon. D Treatment alleviated bodyweight loss. E DAI in the treatment period. F Treatment alleviated the intestinal permeation caused by colitis. G Histopathological assessment of colon tissue sections stained with H&E. The upper panels (scale bar: 500 μm) show the loss of surface epithelium marking ulceration (red arrowhead). The lower panels (scale bar: 100 μm) show the hyperplastic connective tissue (yellow arrowhead) resulting from ulcer lesion and inflammatory cell infiltration into mucosa (red arrow) or submucosa (blue arrow)