Biofabrication aims to design extracellular environments that not only support but also actively guide cellular behavior. This approach primary relies on hydrogels composed of polysaccharides and proteins, which provide a broad range of biochemical, mechanical, and structural cues essential for regulating cell behavior and promoting tissue development. However, conventional fabrication methods struggle to achieve precise control over critical structural elements, such as intricate shapes, anisotropy, and mechanical heterogeneity, hindering the replication of tissue architecture with the necessary complexity. In response, 3D bioprinting technologies have significantly addressed these challenges by improving control over hydrogel engineering, enabling more accurate mimicry of tissue organization. This has facilitated the development of complex, patient-specific constructs that hold significant promise for advancing in vitro disease modeling, tissue regeneration, drug testing, and personalized therapies. 

Despite significant progress, key challenges remain. In particular, the printing of tissues with precise microscale features remains difficult due to the limited resolution of current bioprinting systems. Additionally, a fundamental limitation lies in the static nature of printed constructs, which limits their ability to fully replicate the functional adaptability required for effective tissue regeneration and disease modeling. To address these challenges, the recent emergence of advanced light-assisted bioprinting techniques offers the potential for precise control over the structural and mechanical properties of hydrogels across the micro- to macroscale. Furthermore, the ongoing development of smart hydrogels is paving the way for the fabrication of adaptive and functional constructs that encode the blueprint of their own evolution. This marks the emergence of 4D bioprinting, a new paradigm that integrates time as an engineered, dynamic element, enabling cellular constructs to evolve over time based on predefined physical or biological parameters, and facilitating predictable transformations such as degradation, volumetric swelling, and actuation. Achieving this requires embedding stimuli-responsive behaviors, either within the materials themselves or in cell–matrix composites, to control the construct’s transition in form, function, or size. 

Notably, the 4D concept can be significantly enhanced by integrating DNA-based hydrogels, which, by leveraging the supramolecular properties of complementary nucleic acid sequences, can present bioactive molecules in a reversible manner, opening new avenues for precise control over cellular interactions and advancing sophisticated tissue engineering applications.

Considering these premises, this symposium seeks to highlight the latest advances in the biofabrication of next-generation hydrogels for tissue engineering, with particular focus on the use of adaptive matrices. We propose to explore key areas, including DNA-integrated hydrogels and smart materials, their applications in 3D/4D bioprinting of dynamic scaffolds, and how these factors can be leveraged for tissue and disease modeling. Furthermore, the symposium will address the importance of spatial precision in mechanobiology, examining how finely tuned material properties contribute to our understanding of cellular behavior and tissue development.

The symposium will feature two invited speakers who are actively working on these cutting-edge applications involving DNA-based hydrogels (Prof. Krieg) and advanced bioprinting strategies (Prof. Castilho) and four oral presentations from contributors, potentially spanning multiple continents and representing a diverse range of expertise, including both mid-career and promising early-stage researchers.