Porosity and pore size measurements were conducted using scanning electron microscopy (SEM) images of the hydrogel samples obtained as described previously. For each sample, a total of 8 random spots were imaged at 200x magnification for each test group. The images were analyzed using the Analyze Particles function in ImageJ software (National Institutes of Health, USA). First, the images were imported into the ImageJ software, and a scale was set to establish the pixel-to-distance ratio of the images. The images were then converted to 8-bit format, and the threshold was subjectively adjusted for each image to enhance pore visibility. Next, the Analyze Particles function was employed to calculate the average pore size (µm) and porosity (%) of the hydrogel samples based on the analyzed images.