Spatiotemporal Adaptation in 4D Bioprinting for Dynamic Bone and Cartilage Regeneration

Abstract Bone and cartilage repair is a dynamically evolving process characterized by distinct and sometimes opposing biological demands across regenerative phases. Conventional static scaffolds, including 3D prints, are constrained by “geometric incongruity” and “biological dynamism”, failing to adapt to these temporal changes. 4D bioprinting offers a solution through “Spatiotemporal Adaptation”. A new analytical framework is proposed that classifies 4D strategies into two main categories. Intelligent structural transformation focuses on achieving dynamic shape, property, and mechanical matching. Intelligent functional evolution is defined by its capacity to actively guide these biological processes. These approaches—such as programmed immunomodulation, dynamic matrix stiffening, controlled drug delivery, and vascular‐osteogenesis coupling—are critically evaluated for their application in meeting the phase‐specific demands of bone and osteochondral regeneration. This framework shifts the focus from passive mimicry toward actively guided regeneration, providing a roadmap for next‐generation therapies for complex bone and cartilage defects.