Droplet-based bioprinting

Three-dimensional (3D) bioprinting facilitates the automated patterning of biological entities (such as cells and tissue building blocks) with or without scaffolding biomaterials. The technique enables fabrication of highly organized structures that recapitulate the physiological and biological functions of native tissues. Droplet-based bioprinting (DBB) is unique among the existing bioprinting modalities in its ability to handle and manipulate bioprinting at the cellular level, as well as to develop complex 3D constructs in a high-throughput manner. As an evolving bioprinting modality, DBB has greatly advanced our understanding of cell interactions, tissue and organ formation, and human disease. This Primer gives an overview of the methodology of DBB, detailing its various modalities and its associated hardware and software, including the selection of bioinks and substrates, as well as their interactions and compatibility with different DBB sub-modalities. Finally, recent advances and several limitations of DBB are summarized and considerations are discussed for potential improvements to the technology in the future.