Construction of gelatin-alginate scaffolds containing chondrocytes using 3D bioprinting technology for the study of in vitro cartilage senescence

Osteoarthritis (OA) is an age-related degenerative joint disease characterized by progressive cartilage deterioration. Chondrocyte senescence is recognized as a key contributor to the onset and progression of OA. Establishing reliable cartilage senescence models is therefore essential for elucidating the underlying mechanisms and developing preventive strategies for OA. Three-dimensional (3D) bioprinted models offer significant advantages in precisely controlling tissue architecture, enabling spatial delivery of bioactive molecules, and supporting dynamic cell culture. In this study, we employed 3D bioprinting technology to construct cartilage models and subsequently established cartilage senescence models using hydrogen peroxide (H₂O₂). First, gelatin-sodium alginate hydrogel scaffolds provided favorable mechanical strength and porosity, creating a supportive microenvironment for chondrocyte proliferation. Second, these scaffolds exhibited excellent biocompatibility and effectively promoted extracellular matrix synthesis and secretion. By comparing H₂O₂-induced 2D chondrocyte senescence models with 3D bioprinted cartilage senescence models, our results demonstrated that the 3D models more closely mimicked the molecular characteristics of naturally aged human cartilage. Therefore, the 3D bioprinted cartilage senescence models represents a promising experimental platform for investigating the pathogenesis and prevention of age-related OA.