Fig. 1.

Overview of the cellular interaction between different cell types with endothelial cells in vascularization using a co-culture approach. Endothelial cells have been co-cultured with numerous supporting cells such as fibroblasts, osteoblasts, pericytes or mesenchymal stem cells etc. with or without scaffold through cell signaling and release of cytokines and growth factors or both to induce angiogenesis. These cell–cell communications occur mainly in two forms i.e. direct co-culture approach in two-dimensional or three-dimensional (with scaffold) in which cells interact through secreted signaling factors, cell–cell adhesion and cell–ECM adhesion whereas indirect co-culture approach either in transwell system using semi-permeable membrane, with conditioned medium containing soluble factors released by another cell or with conditioned extracellular matrix (ECM) produced by another cell. In this type, cells are not in direct contact, therefore, cell interaction occurs only through soluble factor signalling