Abstract
Post-fabrication formation of a proper vasculature remains an unresolved challenge in bioprinting. Established strategies focus on the supply of the fabricated structure with nutrients and oxygen and either rely on the mere formation of a channel system using fugitive inks or additionally use mature endothelial cells and/or peri-endothelial cells such as smooth muscle cells for the formation of blood vessels in vitro. Functional vessels, however, exhibit a hierarchical organization and multilayered wall structure that is important for their function. Human induced pluripotent stem cell-derived mesodermal progenitor cells (hiMPCs) have been shown to possess the capacity to form blood vessels in vitro, but have so far not been assessed for their applicability in bioprinting processes. Here, we demonstrate that hiMPCs, after formulation into an alginate/collagen type I bioink and subsequent extrusion, retain their ability to give rise to the formation of complex vessels that display a hierarchical network in a process that mimics the embryonic steps of vessel formation during vasculogenesis. Histological evaluations at different time points of extrusion revealed the initial formation of spheres, followed by lumen formation and further structural maturation as evidenced by building a multilayered vessel wall and a vascular network. These findings are supported by immunostainings for endothelial and peri-endothelial cell markers as well as electron microscopic analyses at the ultrastructural level. Moreover, endothelial cells in capillary-like vessel structures deposited a basement membrane-like matrix at the basal side between the vessel wall and the alginate-collagen matrix. After transplantation of the printed constructs into the chicken chorioallantoic membrane (CAM) the printed vessels connected to the CAM blood vessels and get perfused in vivo. These results evidence the applicability and great potential of hiMPCs for the bioprinting of vascular structures mimicking the basic morphogenetic steps of de novo vessel formation during embryogenesis.
Highlights
IntroductionVascular disorders are the main reason for cardiovascular diseases (e.g. coronary artery disease) which are leading death cause worldwide
Vascular disorders are the main reason for cardiovascular diseases which are leading death cause worldwide
The Human induced pluripotent stem cells (hiPSCs) were generated from commercially available normal human dermal fibroblasts by reprogramming, using either the hSTEMCCA-lentiviral construct [28, 29] or a Sendai virus reprogramming kit (CytoTune 2.0 Sendai reprogramming vectors, Ref#A16517; Lot#A16517, Invitrogen, Carlsbad, CA). hiPSCs were cultured on hESC-qualified Matrigel® (Corning, New York, NY, USA)-coated culture plates in StemMACS iPS Brew medium (Myltenyi Biotec, Bergisch Gladbach, Germany)
Summary
Vascular disorders are the main reason for cardiovascular diseases (e.g. coronary artery disease) which are leading death cause worldwide. The first steps of creating artificial blood vessels were undertaken by tissue engineering approaches, e.g. cell seeding into the decellularized matrix [1], annular mode casting [2] and seeding endothelial cells (ECs) into tubular structures that were created using collagen or collagen with some other matrix components like elastin [3,4,5]. Further attempts were made using biomaterials that were constructed as basic vascular structures and again seeded with multiple cell types [6, 7]. While these approaches resulted in tubular conduits, the spatial distribution of the used cell types as well as the scaffold architecture remained incomplete. Bilayered small vessels were bioprinted using human umbilical vein endothelial cells (HUVECs) and smooth muscle cells (SMCs) [8]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
