This Special Issue focuses on Smart Materials for 4D Bioprinting, highlighting emerging material systems that enable time-dependent, stimuli-responsive, and programmable transformations in bioprinted constructs. By integrating advances in biomaterials chemistry, cell–material interactions, and additive manufacturing, 4D bioprinting provides unprecedented opportunities to recapitulate dynamic biological processes such as tissue morphogenesis, maturation, and regeneration. This issue aims to showcase the design of smart bioinks and structural materials that respond to physical, chemical, and biological stimuli, including temperature, moisture, light, ions, and cellular forces, to achieve controlled shape morphing, functional evolution, and spatiotemporal regulation of tissue properties. Both fundamental studies elucidating underlying mechanisms, theoretical modeling, and AI/ML-assisted design, as well as applied research demonstrating biomedical and bioengineering applications, are welcome. Collectively, this Special Issue seeks to advance the rational design of dynamic biomaterials and accelerate the translation of 4D bioprinting toward next-generation tissue engineering and regenerative medicine.

This Special Issue aims to promote the rational design of dynamic biomaterials and to accelerate the development of 4D bioprinting technologies. It focuses on smart materials for 4D bioprinting and related research, and seeks to collect the latest advances in stimulus-responsive, programmable, and dynamic biomaterials.

Topics of interest include, but are not limited to:

• Stimulus-responsive bioinks and smart materials

• Shape-memory and deformable hydrogels

• Dynamic material–cell interactions

• Structural design and fabrication strategies for 4D bioprinting

• Mechanistic studies, theoretical modeling, and AI/ML-assisted design

• Applications of 4D bioprinting in tissue engineering and regenerative medicine

This Special Issue welcomes original research articles, reviews, and perspectives that integrate both fundamental and applied research, aiming to advance the translational progress of tissue engineering and regenerative medicine applications.