Fig. 2: Optimization of fiber fabrication.

a Illustration of the preparation of zein-coated alginate (ZA) fibers using a wet-spinning technique. Scale bar = 1 cm. b Photograph of ZA fibers with different zein concentrations (10%, 20%, 30%) and quantification of the % area of remaining zein after phosphate-buffered saline washing in each group. Data are shown as the means ± standard deviation (s.d.) (n = 10; *P < 0.05; ***P < 0.001; ns, not significant, according to Student’s t test). c Relationship between fiber diameter and needle diameter in four groups (alginate (A), soaked A, ZA, and soaked ZA fibers). Data are presented as means ± standard deviation (s.d.) (n = 10; **P < 0.01; ***P < 0.001) and were analyzed using one-way ANOVA followed by Tukey’s post-hoc test. d Fluorescence microscopy images of C2C12 cells treated with ZA fibers produced using different needle diameters (20 G, 22 G, 26 G, and 30 G). Cells were immunostained with α-tubulin (green), and nuclei were stained with 4,6-diamidino-2-phenylindole dihydrochloride (DAPI; blue). Scale bar = 100 µm. e Alignment analysis of C2C12 cells within ZA fibers produced using different needle diameter sizes (20 G, 22 G, 26 G, and 30 G). Cells with an alignment angle close to 0° indicate that they are oriented along the microfibers.