ArchiTissue - 3D-Architecture of biohybrid cardiovascular implants by additive manufacturing

生物杂交植入物的生产需要将活细胞和非活支架以特定的3D排列相结合，以获得在组成和功能上概括天然组织的组织。理想情况下，支架提供整体几何形状和结构稳定性，同时定义具有定制属性的3D微环境，以指导细胞生长和细胞外基质合成。支架的设计和材料特性以多种方式影响细胞的行为，最终影响最终组织的功能。本项目的目的是研究精确定义的3D支架结构对功能生物杂交植入物成熟的影响。该项目依赖于添加剂制造技术的能力，以控制聚合物支架的孔大小、形状和互连性以及机械和结构性能的空间分布。在《档案》杂志中，我们将应用细胞相容预聚体的无引发剂激光聚合与立体光固化(SL)相结合来创建各种微结构作为构建块，这些构建块可以选择性地组装成3D宏观几何图形。这样获得的微结构对细胞行为的影响将通过血管内皮细胞和血管内皮细胞的单一和联合培养来研究，在结构日益复杂的情况下。事实上，与制造技术相关的高自由度允许制造具有天然组织典型的非均匀组成和各向异性属性的支架。根据研究结果，将确定开发多层生物混合心脏瓣膜的框架条件。这些条件和参数将被收集在一个结构目录中，该目录将作为生物杂交植入物的通用平台，并作为此类植入物成熟模型的输入。心脏瓣膜叶的三层结构，即富含胶原的纤维膜、富含糖胺聚糖的海绵膜和富含弹性蛋白的室壁，将通过支架在特定生物反应器中的细胞定植来实现。为此，首先为每一层量身定做机械性能和微结构，以影响内皮细胞和平滑肌细胞的行为，特别是关于细胞外基质的产生。将解决以下科学问题来实现该项目的目标：1)通过结合多光子聚合和SL2)结合微观和宏观结构来创建3D结构2)在生物反应器中静态和动态培养下3D结构和细胞之间的相互作用3)开发用于心脏瓣膜组织工程的多层仿生生物混合模型

The production of biohybrid implants requires the combination of living cells and non-living scaffolds in a specific 3D arrangement to obtain tissues that recapitulate native ones in their composition and function. Ideally the scaffold provides the overall geometry and structural stability and at the same time defines the 3D microenvironment with tailored properties to guide cellular growth and extracellular matrix synthesis. The scaffold design and the material properties affect the cell behavior in multiple ways, ultimately influencing the final tissue’s function. The aim of this project is to investigate the influence of precisely defined 3D scaffold architectures on the maturation of functional biohybrid implants. The project relies on the capability of additive manufacturing techniques to control the spatial distribution of pore size, shape and interconnectivity as well as mechanical and structural properties of polymeric scaffolds. In ArchiTissue, we will apply initiator-free laser polymerization of cytocompatible pre-polymers in combination with stereolithography (SL) to create a variety of microstructures as building blocks which can be selectively assembled into 3D macro geometries. The effect of the so obtained microarchitectures on cell behavior will be investigated with mono- and co-culture of smooth muscle cells and endothelial cells, in structures of increasing complexity. Indeed, the high degree of freedom associated with the fabrication technique allows to create scaffolds exhibiting non homogeneous composition and anisotropic properties typical of native tissues. Based on the results, the framework conditions for the development of a multi-layer, biohybrid heart valve will be determined. These conditions and parameters will be collected in a structural catalogue which will serve as a general platform for biohybrid implants as well as input for a maturation model of such implants. The three layers of a heart valve leaflet, the collagen-rich fibrosa, the glycosaminoglycan-rich spongiosa and the elastin-rich ventricularis, will be realized by the cell colonization of the scaffold in ad-hoc developed bioreactors. For this purpose, the mechanical properties and the microarchitecture are first tailored for each layer to influence the behavior of the endothelial and smooth muscle cells, especially with respect to the production of the extracellular matrix.The following scientific questions will be addressed to achieve the project’s aim:1) Creation of 3D architectures by combination of micro- and macroscale structuring by combining multiphoton polymerization and SL2) Investigation of the interaction between 3D architecture and cells under static and dynamic cultivation in bioreactors3) Development of a multi-layered biomimetic biohybrid model for heart valve tissue engineering