ABSTRACT
Bioprinting is defined as the patterning of cell-encapsulating biomaterials (bioinks) in three dimensions. Precise control over the spatial patterning of cells and biomaterials to encourage tissue formation makes bioprinting a promising strategy for tissue engineering (TE) and regenerative medicine. However, limitations in contemporary bioprinting approaches are primarily due to the narrow range of bioink materials. Bioinks for 3D printing can be composed of natural or synthetic polymers that resemble the natural extracellular matrix (ECM). There are many important considerations when designing a bioink, including biocompatibility, bioactivity, cell viability, and printability. This chapter primarily focuses on extrusion-based bioinks with a focus on gel-phase bioinks. We first elaborate the conflicting concerns with producing an extrudable, self-supporting bioink that simultaneously supports the viability of encapsulated cells. Properties of an ideal bioink and bioprinting system such as cross-linking mechanism and bioprinter parameters are outlined. We then elaborate on specific bioink formulations tailored to a variety of TE and regenerative medicine applications.
