WEB 3D PRINTING OF VASCULAR STRUCTURES FROM STEM AND PROGENITOR CELLSWednesday (23.09.2020) 13:00 - 13:01 Poster Room Part of:
The overarching goal of the work is to biofabricate a vascular system with hierarchic vessels, e.g. micro and macro vessels having the typical three-layers, namely intima, media and adventitia using stem and progenitor cells, namely, vascular wall resident stem cells (VW-SCs) and iPSC-derived mesodermal progenitor cells (hiMPCs). Both cell types are a suitable cell source with the capacity to deliver all components of a blood vessel wall such as endothelial cells, smooth muscle cells, pericytes as well as fibroblasts or mesenchymal cells (1).
To bioprint this new cell source, gelatin and its derivative gelatin methacryloyl were used due to its close molecular structure and function with collagen, biodegradability and cell adhesion sites. GelMA was prepared through synthesis of gelatin with methacrylic anhydride (MAA). The degree of substitution (DS) of GelMA is one of the main factors that can influence biophysiochemical properties of GelMA and its photocured hydrogels. First, we used unmodified, with transglutaminase cross-linked gelatin to investigate the cellular response. We observed that gelatin not only provides sufficient structural integrity but also regulates proliferation and differentiation capacity of the cells. Cell attachment, migration, elongation were pronounced in the early days of culturing. Even under simulated stressful printing conditions cellular proliferation, differentiation and morphogenesis were evident. It could be demonstrated that the cells maintain their capacity to form vascular structures in enzymatically cross-linked gelatin. Subsequently, GelMA was used for the bioprinting approach due to tailorable mechanical properties and its printability. Besides simple lattice structures out of hiMPCs and GelMA, we also simultaneously printed with gelatin as sacrificial ink to obtain horizontally porous scaffolds. Further studies on determining the optimal bioink, printing and photo-crosslinking conditions for VW-SCs and hiMPCs are ongoing.
This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Projektnummer 326998133 – TRR 225 (subproject B04).