INSERM, Bioingénierie Tissulaire, U1026, 146 rue Léo Saignat, F-33076, Bordeaux, France.
Université de Bordeaux, Bioingénierie Tissulaire, U1026, 146 rue Léo Saignat, F-33076, Bordeaux, France.
J Mater Sci Mater Med. 2019 Feb 12;30(2):28. doi: 10.1007/s10856-019-6230-1.
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.
将微血管结构发展成为组织工程化骨替代物是当前的一个挑战。将内皮细胞接种到合适的环境中可以产生类似毛细血管的网络，从而增强骨替代物的血管预形成。生物制造技术的进步，如生物打印，可以精确地将内皮细胞图案定义在适合体内应用的生物材料上。本研究的目的是在准备打印另一个内皮细胞层的表面的同时，按照特定的图案产生一个微血管网络并将其保留下来。我们首先优化了生物墨水细胞浓度和激光打印参数，然后开发了一种方法，使内皮细胞能够在两层胶原之间存活。激光辅助生物打印（LAB）用于将 tdTomato 标记的内皮细胞与间充质干细胞共培养后，在胶原水凝胶上进行图案化。毛细血管样结构的形成依赖于内皮细胞的局部足够密度。用含有血管内皮生长因子（VEGF）的胶原 I 水凝胶覆盖图案，可以形成毛细血管样结构，并随着时间的推移保留打印图案。结果表明，激光辅助生物打印是一种有价值的技术，可以将内皮细胞预先组织成高密度图案，以便在基于胶原水凝胶的组织工程构建体中创建具有特定结构的血管网络。
