Bionic Hydrogels Inspired by Articular Cartilage with Lipid-Based Boundary Lubrication Properties

Articular cartilage has limited regenerative capacity after injury due to the absence of vascular and neural tissue. The most common treatment for cartilage damage is surgical implantation of synthetic substitutes. In this study, we developed a biomimetic agarose/PVA hydrogel (AG/PVA-D-S) for cartilage replacement using freeze–thaw and salt-out methods, demonstrating an exceptional performance. The stability of the hydrogel’s polymer network is significantly enhanced by intermolecular and intramolecular hydrogen bonding between the agarose in AG and the crystalline poly(vinyl alcohol) in PVA. Additionally, low-concentration liposomes with highly hydrated choline phosphate headgroups contribute to reduced friction through a hydration lubrication mechanism. As a result, the hydrogel exhibits excellent mechanical properties, including a compressive strength of 5.52 MPa, an elastic modulus of 2.36 MPa, and a compressive strain of 75%, along with excellent self-recovery capabilities. Moreover, it shows a low coefficient of friction (COF ∼0.027) and good biocompatibility. Overall, this hydrogel holds significant potential as a biomimetic material for articular cartilage replacement.