Csaba Gergely (Würzburg, DE), Prof. Dr. Tomasz Jüngst (Würzburg, DE), Michael Bartolf-Kopp (Würzburg, DE), Prof. Dr. Jürgen Groll (Würzburg, DE), Gabriel Größbacher (Utrecht, NL), Paulina Núñez Bernal (Utrecht, NL), Sammy Florczak (Utrecht, NL), Mylène de Ruijter (Utrecht, NL), Núria Ginés Rodriguez (Utrecht, NL), Prof. Dr. Jos Malda (Utrecht, NL), Prof. Dr. Riccardo Levato (Utrecht, NL)
Abstract text (incl. figure legends and references)
Volumetric printing (VP) is a novel, cell-friendly 3D printing method capable of in situ encapsulation of cells into CAD-designed models in a one-step process within seconds. This leads to the fast manufacturing of usable sample sizes of complex hydrogel scaffolds. With this method, complex objects can be created that were not able to be printed with conventional biofabrication methods, such as multi-material objects or intricate tubular branching constructs.
Models for coronary arteries, especially, are needed for medical training and therapeutic replacement purposes. Even 1:1 copies of 3D-scanned tissue, such as CT scans of blood vessel systems of the coronary tree, can be used.
For bioresins, which are a bioink formulation used for vat and vial-based biofabrication techniques, a cytocompatible and photocrosslinkable hydrogel precursor needs to be chosen, with methacrylated gelatin (GelMA) as a prototypical representative. GelMA"s thermal gelling behavior, good optical transparency and its properties can be tuned via the formulation of the precursor solution. This results in different mechanical stiffness, printing resolution, and biological behavior to mimic the extracellular matrix (ECM) for the various cell types in volumetric bioprinting.
The tubular models can be post-seeded with endothelial cells and cultivated under physiological flow to further investigate artificial small-diameter blood vessel models. To prevent cell sedimentation, enhance cell distribution, and provide a beneficial physiological environment for cell maturation, special properties for the resin need to be established. By combining chemistry and biofabrication with tight feedback loops to biology, we are testing advanced in vitro vasculature models.
However, these properties can only be optimized up to a certain point. Research into alternatives or new polymeric options for photosensitive fabrication needs to be conducted to push the limits of printability and biocompatibility.