Engineering Cartilage‐Like PVA Hydrogels: Dual‐Stage Crystallization Kinetics Regulations Overcome the Strength–Water Content Trade‐Off

The development of PVA hydrogels for cartilage repair is limited by the challenge of simultaneously combining high mechanical strength with high water content. To address this, a "Dual-Stage Temperature-Controlled Crystallization Quenching Method" is proposed. The approach precisely regulates crystallization kinetics, enabling meticulous control over the gel network topology. The obtained hydrogel achieves a water content of 83.41% ± 0.51%, a tensile strength of 2.68 ± 0.14 MPa, and a compressive modulus of 0.53 ± 0.02 MPa, exceeding machine learning-predicted thresholds for each property by over 300%. This performance is attributed to a uniform, isotropic network of refined crystallites, as revealed by multiscale analysis, which facilitates homogeneous stress distribution and efficient energy dissipation. Furthermore, the hydrogel possesses a low friction coefficient, biomimetic porosity, and excellent chondrocyte compatibility. This work provides an advanced cartilage repair material and establishes a novel thermodynamic paradigm for polymer gel design through crystallization kinetics regulation.