Fig. 1

Preparation and Characterization of NDF-Ms. A Visualizing the morphologies of NDFs by AFM images. A drop of NDF suspension (50 μg/mL) was placed on a mica plate and then dried at room temperature for AFM observation. B Immune staining of IL-1β distributed in the colorectum in wild-type mice and mice with gross enteritis. C Binding efficiency of proteins and 5-ASA on the surface of NDFs (mg/mg). Proteins and 5-ASA were quantified by a BCA Protein Assay kit (BCA kit) and fluorescence intensity detection at 500 nm. Data are displayed as the mean ± SD (n = 3 independent samples). D Hydrodynamic length changes from NDFs to NDF-pro/5-ASA in DI H₂O solution. The changes demonstrated the synthesis of intermediate NDF-pro/5-ASA. E Bacterial growths exposed to NDF-Pro/5-ASA were observed in the MRS medium or basal medium by measuring the optical density (OD) at 595 nm. CFUs were determined at 12 h to visualize the bacterial cells. F Qualitative analysis of 5-ASA. 5-ASA was detected and qualitatively analyzed at 1.91 min (m/z = 154 for 5-ASA, red arrow) by LC − MS/MS. G Representative images of NDF-Ms. NDF-M microspheres were prepared by extruding 1.5% w/v alginate solutions containing NDF-Pro/5-ASA and Bac into CaCl₂ solution (0.1 M) with an electrostatic droplet generator. NDF-M microspheres were captured to visualize NDF-Pro/5-ASA distributions by confocal microscopy