FIGURE 1.

Schematic illustration showing the indirect 3D bioprinting process for blood vessels and vascularized tissue constructs. (A) Three major techniques used in indirect 3D bioprinting for both sacrificial mold and patrix fabrication, including extrusion-based printing, inkjet-based printing, and DLP printing. (B) Process of blood vessel fabrication. (C) Process of vascularized tissue construct fabrication. Sacrificial mold and patrix fabrication can be further divided into three methods according to the sequence of fabrication in step 1. (D) Applications in vitro or in vivo. Blood vessel grafts constructed by indirect 3D bioprinting are currently used for studies in vitro, while vascularized tissue constructs are used for both studies in vitro and animal experiments in vivo.