Rapidly Forming Recombinant Miniature Spidroins Hydrogels Composed of Nanofibrils with Tunable Mechanical Properties for Bio 3D Printing and Biomimetic Cellular Scaffolds

Recombinant spidroins offer numerous possibilities for creating new biomaterials. However, their polymorphic and prone to aggregation characteristics present challenges in both their production and practical application. Here, mutant recombinant spidroins are reported forming hydrogels rapidly and controllably at 37 °C and with visible light irradiation. In the mutant spidroins phenylalanine residues (F) are systematically substituted by tyrosine residues (Y) in repeat motifs of (GGX), which contributes to the self-assembly of β-sheet and further formation of amyloid-like nanofibrils. As expected, micellar/globular spidroins solution converts to spidroins hydrogel composed of nanofibrils network and subsequently further crosslinked by di-tyrosine. The conformation transformation process is verified by spectroscopy, transmission electron microscopy (TEM), and molecular dynamics simulation. Furthermore, the spidroin hydrogels are used as bioink and biomimetic cellular scaffolds according to their good biocompatibility, shear thinning properties, and nanofibril network structure. The findings reveal the structural transformation mechanism of spidroins and expand their applications in biomedical engineering. © 2024 Wiley-VCH GmbH.