Recent advances in 3D printing sacrificial templates for fabricating engineered vasculature

Abstract

Fabricating engineered vasculature within biological scaffolds is one of the most common strategies to maintain high cell viability before implantation. Many studies have been conducted from the aspects of the manufacturing process, materials science, and cell biology to fabricate engineered vasculature with the aim of enhancing the integration between scaffold and host. Among them, the method of combining three‐dimensional (3D) printing and sacrifice‐based technique has attracted extensive attention. Taking advantage of 3D printing, the method of separating the printed sacrificial template from the biological scaffold to form a 3D channel has become a widely used approach to advance the engineered vasculature. With the development of 3D printing techniques and material science, numerous sacrificial materials have shown their potential in fabricating engineered vasculature. However, several issues remain in this multimethod design, including, but not limited to, the printing process, removal method of sacrificial material, and cell seeding method. This review aims to summarize recent strategies for 3D printing sacrificial templates for fabricating engineered vasculature. The pros and cons of sacrificial materials used in these studies are analyzed. Future perspectives are proposed to fabricate biomimetic‐engineered vasculature. Flexible fabrication processes and materials should be advanced to support the 3D printing of sacrificial templates.

The Use of Additive Manufacturing Techniques in the Development of Polymeric Molds: A Review

“…One of the most intensively used polymers for development of sacrificial molds is PVA, as it is a hydrophilic and therefore a water-soluble, biocompatible, mechanically stable with low toxicity compound that can be easily processed as it can be printed at around 180 • C. PVA was often used to produce sacrificial molds for scaffolds made of PDMS [138,171,173], gelatin [174], fibrin or other materials used to produce different small-scale detailed patterns needed in engineering vasculature or other channel networks applications. The fabrication of sacrificial PLA templates or molds is generally performed via FDM printing [175].…”

“…PVA was often used to produce sacrificial molds for scaffolds made of PDMS [ 138 , 171 , 173 ], gelatin [ 174 ], fibrin or other materials used to produce different small-scale detailed patterns needed in engineering vasculature or other channel networks applications. The fabrication of sacrificial PLA templates or molds is generally performed via FDM printing [ 175 ].…”

“…Lee et al conducted research studies using thermosensitive PNIPAM as a sacrificial template to fabricate microvascular networks within gelatin scaffolds, removing the mold/template by the solvent-spinning method [ 184 ], and further comparing the effects of PNIPAM-fabricated microchannels and macrochannels on the formation of normal functional vessels [ 185 ]. PNIPAM sacrificial molds are generally produced by electrospinning with microfibers, increasing the scalability of the 3D-printed sacrificial template [ 175 ].…”

“…PCL sacrificial molds were used to produce vascular niches and sweat gland interactive models and were removed by incubation with chloroform after dehydration, leaving behind porous constructs [ 195 ]. For sacrificial PCL templates with small-size features, electrospinning and electrohydrodynamic jet printing are often used, being extremely useful for engineering vasculature [ 175 ].…”

“…Three-dimensional printing sacrificial templates have shown remarkable potential for fabricating intricate structured engineered vasculatures due to their feasibility and versatility, but there are still studies needed to overcome the challenges in producing biomimetic vasculature, related to building of hierarchical vasculature within tissue engineering scaffolds [ 175 ].…”