The functionality of living tissues is intimately linked to their intricate and highly specialized architecture. Tissues and organs are composed of multiple types of cells and extracellular matrix (ECM) components and, with few exceptions, are infiltrated with vascular and neural networks. The hierarchical spatial arrangement of these elements is paramount to how they interact with each other and, thus, closely orchestrates several processes during embryonic development,1 in healthy tissue homeostasis, as well as during tissue regeneration.2 Strategies to generate cell–material constructs that ultimately yield a healthy and mature functional tissue remains a major challenge in the field of regenerative medicine.
With the introduction of additive manufacturing, technologies became available to design and fabricate 3D material scaffolds with unprecedented shape and precision. Although, many of these technologies are potentially harmful for active biological components, including living cells, biological matter can successfully be used as building blocks for the generation of living 3D objects.