Proteins and Polypeptides as Biomaterials Inks for 3D Printing

Protein-based materials have recently gained extensive attention as ink and bioink for 3D printing application due to their tunable properties and biocompatibility with the ability to mimic the biochemistry of the cell’s extracellular matrix (ECM). The presence of multiple functional groups on the polymer chains of these naturally derived materials makes them suitable candidates for different crosslinking methods such as physical gelation, chemical and enzymatic reactions, as well as photocrosslinking methods which are the essential step for the filament formation in 3D printing processes. However, batch-to-batch variation of the protein materials due to the diversity in resources and the extraction methods remains a challenge. This chapter provides an overview of the major proteins as ink materials and the crosslinking methods that have been used to tune their properties for 3D printing.