Substrate-Dependent Variability in Viability and Angiogenic Marker Expression Among Three Endothelial Cell Subtypes: Insights for Artificial Tissue Vascularization.

Tissue engineering faces the challenge of achieving effective vascularization within tissue constructs for sustained viability and optimal function. The success of tissue-engineered constructs depends on selecting an optimal angiogenesis-stimulating ECM substitute material. This study compares four substrates made from three different biomacromolecules-fibrin, fibronectin, non-crosslinked, and crosslinked gelatin, and their effect on endothelial cells. Acknowledging the diverse range of endothelial cells that play a role in (micro)vascularization, human endothelial primary cells, human umbilical vein endothelial cells, and human microvascular endothelial cells are subjected to these materials for evaluation. Biocompatibility is assessed by measuring cell viability (Live/Dead assay), metabolic activity (alamarBlue assay), morphology (actin staining), phenotype expression (immunocytochemistry), and the production of von Willebrand factor, which promotes angiogenesis by promoting cell adhesion and migration. The results show that the use of biomaterials as culturing substrates significantly impacts the viability and morphology of the cells. While the expression of angiogenic markers is shown to rely more on the cell lineage, the use of different substrates has an impact on the expression timeline. Thus, combining cells and biomaterials in a favorable manner can be used as a powerful tool for controlled vascularization in vitro, which requires the systematic assembly of different stimuli.