Particulated juvenile articular cartilage (PJAC) has emerged as a promising living material for articular defect treatment. However, the fragile nature of PJAC hinders its wide clinical application. Here, inspired by the chemical composition and hierarchical structure of natural cartilage, we developed a novel hydrogel carrier system for PJAC delivery. Our carrier system, MeHA@J@DM, utilized methacrylated hyaluronic acid (MeHA) to incorporate PJAC and coated it with a polymerized mixture of dopamine methacrylamide (DMA) and 2-methylacryloyloxyethyl phosphorylcholine (MPC), forming an adhesive lubricant, p(DMA-MPC). MeHA@J@DM exhibited excellent performance for PJAC protection with enhanced cell viability, bioactivity, and lubrication properties. We evaluated the effectiveness of MeHA@J@DM in cartilage cell migration, where juvenile cartilage showed greater efficiency and remodeling abilities. In vivo rabbit cartilage defect models demonstrated superior cartilage regeneration with the MeHA@J@DM hydrogel. Our findings suggest that MeHA@J@DM has translational potential for PJAC implantation to enhance cartilage regeneration and benefit patients with articular cartilage lesions.
Polyetheretherketone (PEEK) has an elastic modulus similar to that of the bone; however, its use as a material for bone repair is limited by bio-inert surface chemistry and poor osteogenesis-inducing capacity. To address this issue, the PEEK surface was activated by ultraviolet radiation-induced grafting of methacrylated hyaluronic acid (MeHA) and titanium dioxide (TiO 2 ) nanofibers via a one-step process. The modified PEEK surface was characterized by X-ray photoelectron and Fourier-transform infrared spectroscopy, and the extent of surface modification was evaluated by measuring static contact angles. Atomic force microscopy revealed that the PEEK surface grafted with electrospun TiO 2 had abundant nanofibers and a roughness that was comparable to that of human cortical bone. In vitro experiment, rat bone mesenchymal stem cells showed increased adhesion, proliferation, and osteogenic differentiation capacity on TiO 2 -modified as compared to unmodified PEEK. Thus, PEEK that is surface-modified with electrospun TiO 2 and MeHA has enhanced biocompatibility and can be an effective material for use in orthopedic implants and medical devices.