Microstructure of the Silk Fibroin-based Hydrogel Scaffolds Derived from the Orb-web Spider Trichonephila clavata

Abstract Due to the unique properties of the silk fibroin (SF) from silkworm the SF-based hydrogels recently received significant attention for various biomedical applications. However, researches regarding the SF-based hydrogels isolated from spider silks have been comparatively restricted due to shortage of collection and preparation of naïve silk materials. Therefore, this study focused on the microstructural characteristics of hydrogel scaffolds derived from two types of woven silk glands – major ampullate gland (MAG) and tubuliform gland (TG) - in the orb-web spider Trichonephila clavata and compared them with those of silk fibroin (SF) hydrogel scaffold extracted from the cocoon of the insect silkworm Bombyx mori. Our FESEM analysis revealed that the SF hydrogel has high porosity, translucency, and a loose upper structure, with attached SF fibers providing stability. The MAG hydrogel displayed even higher porosity, elongated fibrous structures, and improved mechanical properties, while TG hydrogel showed increased porosity, ridge-like or wall-like structures, and stable biocapacity is formed by physical cross-linking. The distinct microstructural characteristics of MAG and TG hydrogels are expected to provide advantages in the selection of tailored substrates to support specific cell types for tissue engineering and regenerative medicine applications.