Dynamically adaptive scaffolds for cartilage tissue engineering

Although cartilage regeneration is a continuously changing, complex process, most studies on cartilage tissue regeneration have focused on specific stages, thereby promoting regeneration in only a limited period rather than over the entire repair process. The ideal adaptive scaffolds for cartilage tissue engineering should exhibit dynamic and spatiotemporally controlled evolution according to the physiological microenvironments during each phase of cartilage repair. Moreover, scaffolds should have a specific feedback regulation capability, including long-term feedback for the controlled delivery of multiple factors, which would better meet the requirements of cartilage regeneration. Adaptive scaffolds matching the whole evolving stages of cartilage repair are still under exploration. This review highlights the development of dynamically adaptive scaffolds to provide the appropriate microenvironments for cartilage regeneration, including scaffolds that manipulate the immune microenvironments from the inflammation stage to the regeneration stage, scaffolds that release cytokines on demand across several stages, and scaffolds that adapt according to the mechanical properties of extracellular matrices over time, and also discusses the future challenges and development directions of adaptive scaffolds in cartilage tissue regeneration. This understanding is expected to inspire the application of adaptive scaffolds for cartilage repair.