Photocrosslinked Silk Fibroin Cryogels for Engineering Complex Multilayered Materials

This study presents a novel photo-initiated crosslinking strategy for assembling modular silk fibroin and gelatin building blocks into complex multizonal cryogel architectures. The technique leverages di-tyrosine bond formation to fuse frozen building blocks into mechanically integrated hydrogels, which upon thawing or freeze-drying exhibit microscale porosity with tunable pore alignment, crosslinking density, and stiffness. The authors demonstrate the first generation of photocrosslinked silk fibroin cryogels, achieving larger and more stable pores than traditionally physically crosslinked cryogels. The platform supports precise spatial patterning of material zones with distinct mechanical and structural characteristics, while enabling covalent immobilization of bioactive molecules for controlled biofunctionality. Cytocompatibility studies confirm that encapsulated cells remain viable, and the modular approach offers scalability for engineering biomimetic, layered constructs resembling muscle, valve, and osteochondral tissue interfaces.