Fig. 4: Hybrid aerogels promote cell infiltration and new blood vessel formation after subcutaneous implantation.

a Schematic illustrating different cross-sections of each explant. b Hematoxylin and eosin (H & E) staining images of native subcutaneous tissue. c, d H & E staining images of different cross-sections of each explant at day 14 and 28. Yellow circles indicate the newly formed blood vessels inside aerogels. Scale bar = 50 µm. Twelve tissue samples were used for histology staining and similar results were obtained. e Cell counts per region of interest (ROI) in each explant. f Percentages of cell infiltrated area in each explant. g Number of newly formed blood vessels in each explant. Data are presented as mean values ± SD, N = 5 (randomly selected five tissue samples). The significant difference was detected by two-way ANOVA with Tukey’s multiple comparisons test. The ‘ns’ indicated no significant difference, *p < 0.01, **p < 0.001, ***p ≤ 0.0003, ****p < 0.0001. 2D NF mat nanofiber mat, NFA nanofiber aerogels coated with 1% gelatin, MFA microfiber aerogels coated with 1% gelatin, NF/MF-A1 hybrid aerogels containing NF/MF at a ratio of 50:50 (w/w) coated with 1% gelatin.