Free-standing fibrinogen scaffolds for cell culture
Hematopoietic stem cells (HSCs) are widely used for the treatment of hematological diseases, as they are able to reconstitute the human blood system. In vivo, HSCs and their progenitors (HSPCs) are localized in and regulated by distinct microenvironments in the bone marrow, their so-called niches. Resembling their natural microenvironment using in vitro models, allows gaining insights about the processes and the cellular interactions of the different cell types in the niche. In the current project, nanofibrous fibrinogen scaffolds were used to mimic the basal lamina of bone marrow sinusoids. One side of the biomaterial was seeded with microvascular endothelial cells (ECs) to recapture the inner layer of the blood vessel. On the other side, mesenchymal stem and stroma cells (MSCs) mimicked the outer layer of the vessel. ECs and MSCs are essential supporter cell types for HSPCs in the vascular niche. To complete the in vitro model, HSPCs, isolated from umbilical cord blood, were introduced to either the EC-seeded side or the MSC-seeded side to imitate residing in or homing to the niche. The first three videos show the handling of the fibrinogen scaffolds. In the first video, the scaffolds were detached from glass coverslips and clamped between two PVC rings. In the next video, the different cell types were seeded on the scaffolds from different sides. The third video shows the unclamping of the scaffold and the mounting, which is needed for the subsequent microscopy of the sample. The following videos show 3D reconstruction videos prepared from microscopy images of the different experimental conditions.
