Thermoplastic Elastomer‐Reinforced Hydrogels with Excellent Mechanical Properties, Swelling Resistance, and Biocompatibility

Strong and tough hydrogels are promising candidates for artificial soft tissues, yet significant challenges remain in developing biocompatible, anti-swelling hydrogels that simultaneously exhibit high strength, fracture strain, toughness, and fatigue resistance. Herein, thermoplastic elastomer-reinforced polyvinyl alcohol (PVA) hydrogels are prepared through a synergistic combination of phase separation, wet-annealing, and quenching. This approach markedly enhances the crystallinity of the hydrogels and the interfacial interaction between PVA and thermoplastic polyurethane (TPU). This strategy results in the simultaneous improvement of the mechanical properties of the hydrogels, achieving a tensile strength of 11.19 ± 0.80 MPa, toughness of 62.67 ± 10.66 MJ m^-3, fracture strain of 1030 ± 106%, and fatigue threshold of 1377.83 ± 62.78 J m^-2. Furthermore, the composite hydrogels demonstrate excellent swelling resistance, biocompatibility, and cytocompatibility. This study presents a novel approach for fabricating strong, tough, stretchable, biocompatible, and fatigue- and swelling-resistant hydrogels with promising applications in soft tissues, flexible electronics, and load-bearing biomaterials.