Micropatterning of endothelial cells to create a capillary-like network with defined architecture by laser-assisted bioprinting
Development of a microvasculature into tissue-engineered bone substitutes represents a current challenge. Seeding of endothelial cells in an appropriate environment can give rise to a capillary-like network to enhance prevascularization of bone substitutes. Advances in biofabrication techniques, such as bioprinting, could allow to precisely define a pattern of endothelial cells onto a biomaterial suitable for in vivo applications. The aim of this study was to produce a microvascular network following a defined pattern and preserve it while preparing the surface to print another layer of endothelial cells. We first optimise the bioink cell concentration and laser printing parameters and then develop a method to allow endothelial cells to survive between two collagen layers. Laser-assisted bioprinting (LAB) was used to pattern lines of tdTomato-labeled endothelial cells cocultured with mesenchymal stem cells seeded onto a collagen hydrogel. Formation of capillary-like structures was dependent on a sufficient local density of endothelial cells. Overlay of the pattern with collagen I hydrogel containing vascular endothelial growth factor (VEGF) allowed capillary-like structures formation and preservation of the printed pattern over time. Results indicate that laser-assisted bioprinting is a valuable technique to pre-organize endothelial cells into high cell density pattern in order to create a vascular network with defined architecture in tissue-engineered constructs based on collagen hydrogel.
This work was supported by the Institut français pour la recherche odontologique (IFRO) and Bordeaux Consortium for Regenerative Medicine (BxCRM). The authors acknowledge «Fondation des Gueules Cassées, Paris-France » (n°54-2017) and « Fondation de l’Avenir, Paris-France» (N°AP-RM-17-038) for their financial support. The authors would also like to thank Sophia Ziane (INSERM U1026, Bordeaux, France), Nathalie Dusserre and Davit Hakobyan (ART Bioprint, INSERM U1026, Bordeaux, France) and Sébastien Marais (Bordeaux Imaging Center, Bordeaux, France) for their excellent technical support.
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Conflict of interest
The authors declare that they have no conflict of interest.
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