Injectable biomaterials-enabled osteoarthritis therapy

Osteoarthritis (OA) is a chronic degenerative joint disorder characterized by progressive articular cartilage degradation, subchondral bone remodeling, and persistent joint pain.In recent years, injectable biomaterials have emerged as a versatile platform for OA therapy, offering minimally invasive delivery with multifunctional capabilities.This review provides a comprehensive overview of injectable biomaterialenabled intra-articular strategies, structured around three core therapeutic objectives: prevention of cartilage degeneration, restoration of cartilage defects, and relief of OArelated pain.We first delineate the pathological landscape of OA, encompassing cartilage and subchondral bone alterations, joint pain mechanisms, and critical microenvironmental factors (including inflammation, oxidative stress, mechanical Downloaded from https://spj.science.orgon October 27, 2026 stress, and osmolarity) that collectively drive disease progression.The physicochemical and functional characteristics of injectable biomaterials are then discussed, highlighting the strategies to enhance material stability, stimuli-responsiveness, and controlled release capabilities.Subsequently, biomaterial-based strategies are critically analyzed according to their therapeutic mechanisms, including lubrication restoration, inflammation and oxidative stress modulation, metabolic homeostasis regulation, and subchondral bone remodeling inhibition for prevention of OA, as well as cell recruitment and stem cell differentiation guidance for cartilage regeneration.Finally, we discuss personalized therapeutic strategies accounting for patient heterogeneity, key translational barriers, and future perspectives for next-generation biomaterials and biomedical devices.By integrating pathological insights with function-oriented material design principles, this review aims to provide a rational framework for advancing injectable biomaterial-based OA therapies from bench to bedside.