A Versatile Method for Fabricating Tissue Engineering Scaffolds with a Three-Dimensional Channel for Prevasculature Networks.

Despite considerable advances in tissue engineering over the past two decades, solutions to some crucial problems remain elusive. Vascularization is one of the most important factors that greatly influence the function of scaffolds. Many research studies have focused on the construction of a vascular-like network with prevascularization structure. Sacrificial materials are widely used to build perfusable vascular-like architectures, but most of these fabricated scaffolds only have a 2D plane-connected network. The fabrication of three-dimensional perfusable branched networks remains an urgent issue. In this work, we developed a novel sacrificial molding technique for fabricating biocompatible scaffolds with a three-dimensional perfusable branched network. Here, 3D-printed poly(vinyl alcohol) (PVA) filament was used as the sacrificial material. The fused PVA was deposited on the surface of a cylinder to create the 3D branched solid network. Gelatin was used to embed the solid network. Then, the PVA mold was dissolved after curing the hydrogel. The obtained architecture shows good perfusability. Cell experiment results indicated that human umbilical vein endothelial cells (HUVECs) successfully attached to the surface of the branched channel and maintained high viability after a few days in culture. In order to prevent deformation of the channel, paraffin was coated on the surface of the printed structure, and hydroxyapatite (HA) was added to gelatin. In conclusion, we demonstrate a novel strategy toward the engineering of prevasculature thick tissues through the integration of the fused PVA filament deposit. This approach has great potential in solving the issue of three-dimensional perfusable branched networks and opens the way to clinical applications.