Abstract
Osteoarthritis leads to the progressive decay of articular cartilage. Due to its intrinsic avascular character, cartilage shows an inadequate capacity for regeneration. Cartilage loss may result in chronic pain, movement disorder and morbidity, which lack effective treatments except for joint replacement for late-stage osteoarthritis. To overcome this challenge, tissue engineering has emerged as a promising method. Scaffolds provide mechanical and biochemical support to stem cells that undergo differentiation and secrete a cartilage-specific matrix, and this strategy has been proven to have positive results. However, there is still a gap between the current strategy and perfection. Researchers are confronted with difficulties such as poor cell survival, insufficient differentiation, hypertrophy and endochondral calcification of neocartilage, and inadequate integration into the host tissue. The current research focuses on modifying scaffold parameters, including composition, stiffness, pore size, surface morphology, hydrophilicity and electric charge. On the other hand, cell regulation is another focus, including predifferentiation, gene editing, dynamic mechanical stimulus, and hypoxia. This review aims to provide a comprehensive discussion of existing challenges, scaffold types and properties, practical methods to improve chondrogenic potential and an outlook on future trends in cartilage bioengineering.