Solvent-based Extrusion 3D Printing for the Fabrication of Tissue Engineering Scaffolds

Three-dimensional (3D) printing has been emerging as a new technology for scaffold fabrication to overcome the problems associated with the undesirable microstructure associated with the use of traditional methods. Solvent-based extrusion (SBE) 3D printing is a popular 3D printing method, which enables incorporation of cells during the scaffold printing process. The scaffold can be customized by optimizing the scaffold structure, biomaterial, and cells to mimic the properties of natural tissue. However, several technical challenges prevent SBE 3D printing from translation to clinical use, such as the properties of current biomaterials, the difficulties associated with simultaneous control of multiple biomaterials and cells, and the scaffold-to-scaffold variability of current 3D printed scaffolds. In this review paper, a summary of SBE 3D printing for tissue engineering (TE) is provided. The influences of parameters such as ink biomaterials, ink rheological behavior, cross-linking mechanisms, and printing parameters on scaffold fabrication are considered. The printed scaffold structure, mechanical properties, degradation, and biocompatibility of the scaffolds are summarized. It is believed that a better understanding of the scaffold fabrication process and assessment methods can improve the functionality of SBE-manufactured 3D printed scaffolds.