Fig. 2

Schwann cell morphology was elongated on nanofibers. (A) Representative images of aligned actin filaments of male (left) and female (right) Schwann cells on (i) controls (ii) 0.9 µm (iii) 1.2 µm (iv) 1.8 µm diameter fibers. The direction of aligned fibers is indicated by the white arrow along the horizontal axis. Actin filaments (green) were labeled using phalloidin-Alexa Fluor 488 and the cell nuclei (blue) were labeled using Hoechst 33342. Scale bar: 50 µm. Images are of the closest data point to the mean in the third quartile of the violin plots. 7 images were taken of each substrate for a total of 21 images per biological replicate. (B) Percentage of actin alignment was measured using a MATLAB edge detection program³⁵. No significant differences were found between female and male cells within any experimental condition. Values reported represent mean ± standard deviation, where 100% indicates perfect alignment. (C) Whole-cell aspect ratio (AR) of individual female and male Schwann cells was measured. Whole-cell AR of male cells was statistically higher than female cells on flat substrates, while female cells are higher than males on 0.9 µm and 1.8 µm fibers. (D) Nuclear eccentricity ratio (ER) of individual female and male Schwann cells was separately examined. ER of female cells on 1.8 µm fibers was statistically higher than male cells. Three biological replicates were completed per sex (N = 3), and greater than 40 individual cells (n) were measured (control: n_male = 144, n_female = 68; 0.9 μm: n_male = 66, n_female = 40; 1.2 μm: n_male = 103, n_female = 63; 1.8 μm: n_male = 101, n_female = 52). Statistical analyses were calculated using two-tailed unpaired t-test (control) and two-way ANOVA test with Tukey as a post hoc test (fiber). Error bar: standard deviation.