Preparation of the silk fibroin 3D scaffolds with large pore sizes and high interconnectivity

Silk fibroin (SF) has a variety of applications in biomedical science. Considering the contradiction between suitable pore size and outstanding mechanical properties, the paper focused on the topic of preparing the 3D scaffolds with large pore sizes and high interconnectivity. The porous scaffolds were prepared by using two methods including a combination of the freeze-drying and paraffin spheres leaching techniques and a combination of the air-dried and salt (NaCl or Na₂CO₃) leaching methods. To remove three porogen agents from the scaffolds, three different methods, i.e., washing by water, chemical reaction and soaking by organic solvent, were selected and tested in the study. After freeze-drying, silk scaffolds with different pore sizes and porosities were obtained. The properties of the prepared 3D scaffolds were evaluated in terms of morphology by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) spectra, porosity and mechanical properties. The best porosity of the prepared sample reached up to 93%.