天然システインリッチタンパク質を用いた硬くて丈夫なヒドロゲルのH₂O₂支援作製

Protein-based hydrogels have emerged as an important class of materials for biomedical applications. However, these hydrogels often exhibit inferior mechanical properties, significantly limiting their potential applicability. Herein, a simplified yet efficient soaking method is developed to broaden the scope of constructing stiff and tough pure protein hydrogels, using natural cysteine-rich proteins, such as lactoferrin (LF). The preformed, soft and brittle, unfolded protein hydrogels transformed into highly stretchable and compressible elastomers after soaking in H₂O₂ due to chain entanglement and self-crosslinking via interchain disulfide bonds. As a result, the H₂O₂-treated LF hydrogels exhibited an extraordinary ultimate strength (compressive and tensile strains of over 90% and 400%, respectively, and stresses of 20 and 1.5 MPa). In addition, these rubber-like hydrogels exhibited exceptional self-recovery and fatigue resistance capabilities. Furthermore, the relationship between protein structure and the mechanical properties of the hydrogel was investigated. Together, these revelations could serve as a guiding principle for advancing the design of biocompatible, tough protein hydrogels without chemical modification or mechanical reinforcing fillers.