In vitro 3D assay to test angiogenic effects of human CD14+ monocytes seeded on macroporous PLGA/CaP polymers with a CaP nanostructured surface

In this study we present a three-dimensional angiogenesis assay in vitro that allows the evaluation of the influence of Poly(lactic-co-glycolic acid) based implants seeded with VEGF-A165 stimulated/activated human CD14+ monocytes on the attraction and migration of human micro vascular endothelial cells (HMVEC-L). Primary HMEC of the capillary bed were cultured on an extracellular matrix generated by bovine corneal endothelial cells (BCEC). The HMEC layer was covered by an agarose gel, upon which a Poly(lactic-co-glycolic acid)/CaP polymer with a Calcium-Phosphate (CaP) nanostructured surface was placed. This scaffold has already been shown to interact with endothelial cells and endothelial progenitor cells respectively in vivo. It was seeded with angiogenically stimulated (VEGF-A165) human CD14+ monocytes, to get a monocyte/macrophage fraction, which can promote angiogenesis, tissue remodelling and tissue repair due to the secretion of growth factors, cytokines, chemokines and enzymes. The study demonstrated that this assay is suitable to test angiogenic effects by stimulated human CD14+ monocytes on human microvascular endothelial cells influenced by Poly(lactic-co-glycolic acid)/CaP scaffolds with a nanostructured CaP surface. The assay can exclude effects on migration caused by gravity and also allows testing in a physiological environment on an extracellular matrix secreted by endothelial cells.