An SEM (FEI Nova NanoSEM 450, Thermo Fisher, Pittsburgh, PA, USA) was used to image the dECM inserts at high (2,000x -20,000x) magnification. An insert was mounted on a pin stub SEM mount (75210, Electron Microscopy Sciences, Hatfield, PA, USA), sputter coated with gold, and imaged on the SEM. The DiameterJ 45 plugin for ImageJ/FIJI was used to measure the diameters of the fibers in SEM images.