Fig. 2: Structure characterization of shell-hardened macroporous hydrogels.

a Micrographs (left) and fluorescent micrographs (right) for the precursors of NN, NP and SP hydrogels. FITC-labelled lysozyme was used in the precursor of SP hydrogels. Each experiment was repeated 3 times independently with similar results. b Optical image of NN, NP and SP hydrogels. c FESEM images of NN, NP and SP hydrogels. Each experiment was repeated 3 times independently with similar results. 3D reconstruction of the macroporous structures in NN (d), NP (e) and SP (f) hydrogels using LCFM. The scanning area was 200 μm × 318 μm × 318 μm. FITC-labelled PEG was used in NN and NP hydrogels to visualize the hydrogel matrix, while FITC-labelled lysozyme was utilized in SP hydrogels to visualize the shells of the macropores. g Enlarged fluorescent micrograph (left) showing the precursors of SP hydrogels, with the corresponding intensity profile (right) along the red line in the left panel. The green shading indicates the ring thickness. h Summary of shell thickness measurements from three independent fabrication batches, determined using fluorescence labelling-assisted analysis in g (n = 43 points for each batch). The p values for the batch 1 and batch 2, batch 2 and batch 3, and batch 1 and batch 3 are 0.4381, 0.0623 and 0.2484, respectively. i Enlarged top view of the 3D reconstruction of macroporous structures in SP hydrogels (left), along with a summary of pore sizes (right) from three different fabrication batches, based on 3D reconstruction analysis (n = 43 points for each batch). The p values for the batch 1 and batch 2, batch 2 and batch 3, and batch 1 and batch 3 are 0.1861, 0.2583 and 0.8003, respectively. Statistical significance was assessed using Student’s t-test. NS: not significant.