Abstract
Tissue-engineered constructs are promising to overcome shortage of organ donors and to reconstruct at least parts of injured or diseased tissues or organs. However, oxygen and nutrient supply are limiting factors in many tissues, especially after implantation into the host. Therefore, the development of a vascular system prior to implantation appears crucial. To develop a functional vascular system, different cell types that interact with each other need to be co-cultured to simulate a physiological environment in vitro. This review provides an overview and a comparison of the current knowledge of co-cultures of human endothelial cells (ECs) with human adipose tissue-derived stem/stromal cells (ASCs) or bone marrow-mesenchymal stem cells (BMSCs) in three dimensional (3D) hydrogel matrices. Mesenchymal stem cells (MSCs), BMSCs or ASCs, have been shown to enhance vascular tube formation of ECs and to provide a stabilizing function in addition to growth factor delivery and permeability control for ECs. Although phenotypically similar, MSCs from different tissues promote tubulogenesis through distinct mechanisms. In this report, we describe differences and similarities regarding molecular interactions in order to investigate which of these two cell types displays more favorable characteristics to be used in clinical applications. Our comparative study shows that ASCs as well as BMSCs are both promising cell types to induce vascularization with ECs in vitro and consequently are promising candidates to support in vivo vascularization.