Engineering strong and tough collagen hydrogels and tissue constructs via twisting and crosslinking

Collagen, a primary component of the extracellular matrix (ECM), is crucial for developing biomimetic materials in tissue engineering and regenerative medicine. However, the limited mechanical properties of collagen-based biomaterials pose significant challenges for load-bearing biomedical applications. In this study, we address this challenge by introducing a novel twisting and crosslinking (TC) method, inspired by towel dehydration, to rapidly fabricate strong and tough collagen hydrogels. We first induce the densification and alignment of self-assembled collagen hydrogels through twisting (T-Col) and then further improve their mechanical properties via chemical crosslinking (TC-Col). Additionally, three-dimensional cell culture experiments reveal that TC-Col supports high cell viability, spreading, elongation, and alignment. We also demonstrate the formation of higher-order collagen structures with tunable mechanical properties, expanding the versatility of this approach. This study provides a robust strategy for engineering strong and tough collagen hydrogels and tissue constructs, offering new insights into tissue strengthening mechanisms and advanced biomedical applications.