Macroporous Silk Nanofiber Cryogels with Tunable Properties

Abstract

Cryogels are widely used in tissue\nregeneration due to their porous\nstructures and friendly hydrogel performance. Silk-based cryogels\nwere developed but failed to exhibit desirable tunable properties\nto adapt various biomedical applications. Here, amorphous short silk\nnanofibers (SSFs) were introduced to fabricate silk cryogels with\nversatile cues. Compared to previous silk cryogels, the SSF cryogels\nprepared under same conditions showed significantly enhanced mechanical\nproperties. The microporous cryogels were achieved under lower silk\nconcentrations, confirming better tunability. Versatile cryogels with\nthe modulus in the range of 0.5–283.7 kPa were developed through\nadjusting silk concentration and crosslinking conditions, superior\nto previous silk cryogel systems. Besides better cytocompatibility,\nthe SSF cryogels were endowed with effective mechanical cues to control\nosteogenetic differentiation behaviors of BMSCs. The mechanical properties\ncould be further regulated finely through the introduction of β-sheet-rich\nsilk nanofibers (SNFs), which suggested possible optimization of mechanical\nniches. Bioactive cargo-laden SNFs were introduced to the SSF cryogel\nsystems, bringing biochemical signals without the compromise of mechanical\nproperties. Versatile SNF-based cryogels with different physical and\nbiological cues were developed here to facilitate the applications\nin various tissue engineering.