In this paper, three different mass fractions of sodium carbonate were used for degumming to obtain different degrees of damaged silk fibroin fibers, which were then treated with formic acid to shrink and bond them into 3D scaffolds. The structure and performance of silk fibroin fibers and silk fibroin 3D scaffolds were characterized by scanning electron microscopy, infrared spectroscopy, X-ray diffraction, a differential thermal scanner, a universal materials testing machine, and laser confocal microscopy, and the degradation performance was tested by protease degradation. The results showed that an excessive mass fraction of sodium carbonate would cause partial hydrolysis of fibroin fibers, decrease the mechanical properties of fibroin fiber, increase the surface roughness of fibroin fibers, and make mouse embryonic fibroblasts easier to adhere and grow. Silk fibroin fibers were slightly dissolved, shrunk, and dispersed in formic acid. The mass fraction of sodium carbonate can adjust the enzymatic degradation rate of the silk fibroin 3D scaffolds. With the extension of the degradation time, minerals will be deposited on the surface of the scaffolds. The results show that the silk fibroin 3D scaffolds have biocompatibility, mechanical properties, and degradability, which provides a good material for a barrier biofilm in the future.
Keywords: biocompatibility; degradation; formic acid; silk fibroin 3D scaffolds; sodium carbonate.