Recellularization potential assessment of Wharton's Jelly-derived endothelial progenitor cells using a human fetal vascular tissue model.

Mesenchymal stem cells isolated from Wharton's Jelly have demonstrated an excellent differentiation potential into the endothelial lineage. We hypothesize that endothelial progenitor cells differentiated from Wharton's Jelly-derived mesenchymal stem cells have the potential to repopulate a decellularized vascular bed employed as a biological scaffold. For this purpose, we aimed at investigating the behavior of the endothelial progenitor cells in the decellularized matrix and their potential to repopulate decellularized human vascular tissue. Our main objectives were to differentiate Wharton's Jelly-derived mesenchymal stem cells into endothelial progenitor cells and to obtain a human vascular tissue slice experimental model using the umbilical cord arteries. We employed a decellularization method using enzymatic treatment of the umbilical cord arteries and a recellularization method with the endothelial progenitor cells differentiated from Wharton's Jelly mesenchymal cells in a co-culture system, in order to investigate our hypothesis. The cellular integration within the biological scaffold was determined by using flow cytometry analysis and confirmed by visualization of histological staining as well as fluorescence microscopy. The morphological observations of the recellularized scaffolds revealed the presence of endothelial progenitor cells within the decellularized tissue slices, displaying no degradation of the scaffold's extracellular matrix. The flow cytometry analysis revealed the presence of Wharton's Jelly-derived endothelial progenitor cells population in the decellularized fetal blood vessel scaffold after recellularization. In conclusion, our results have shown that an in vitro human vascular tissue slice experimental model using decellularized human fetal arteries is able to sustain an adequate scaffold for cellular implants.