Macrophage-mediated angiogenic activation of outgrowth endothelial cells in co-culture with primary osteoblasts

摘要

The rapid and successful vascularization of complex tissue engineered constructs for bone regeneration is still a major challenge in the field of tissue engineering. In this context, co-culture systems of endothelial cells and osteoblasts represent a promising approach to advance the formation of a stable vasculature as well as an excellent in vitro model to identify possible factors that positively influence bone healing processes, including angiogenesis. Under physiological conditions, the activation phase of angiogenesis is mainly induced by hypoxia or inflammation. Inflammatory cells like monocytes or macrophages secrete proinflammatory cytokines and proangiogenic growth factors, finally leading to the formation of new blood vessels. The aim of this study was to investigate if macrophages might positively influence the formation of microvessel-like structures via inflammatory processes in a co-culture system consisting of outgrowth endothelial cells (OECs) and primary osteoblasts (pOBs).