Fabrication of Collagen Scaffolds with Computer Designed Internal Microarchitecture for Blood Vessel Engineering Using Inverse 3D Printing

Three-dimensional(3D) printing and bioprinting has been employed in the production of tissues analogs. These tissues can then be used as transplant alternatives or disease models research. While successful thin(<1mm) tissues are reported, thick tissues(>1mm) are still a challenge to engineer due to lack of functional microvasculature. We present a method where we repurpose a commercial 3D printer into an inverse bioprinter. Using biocompatible raw materials we printed a sacrificial mould into which a type I collagen slurry is cast and solidified. After the sacrificial mould is chemically removed, optical computed tomography reveals predefined scaffold microchannel. Immortalized human umbilical vein endothelial cells (HUVEC-hTERT) were seeded in the scaffold microchannels, incubated for 72 hours and assessed for attachment using scanning electron microscopy. Obtained results demonstrate the ability to use the inverse 3D printing method in a repurposed commercial bioprinter to produce scaffolds with predefined microvasculature for thick tissue engineering applications.