Implementation of endothelial progenitor cells for bone tissue regeneration

• Applicant: Professor Dr. Alexander Hofmann
• Subject Area: Medical Physics, Biomedical Technology ; Orthopaedics, Traumatology, Reconstructive Surgery
• Term: from 2009 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 118723154

Clinical applications of bone tissue engineering have been limited due to a shortage of critical 1 oxygen and nutrient supply after implantation. Improving vascularization by implanting endothelial cells may represent a key solution for engineering bone constructs of large size. Therefore, this application aims to characterize the cellular interactions between human endothelial progenitor cells (EPC) and human osteoblasts (hOB). Based on our preliminary data, which demonstrated that hOB supported cell proliferation and in vitro vasculogenesis of human umbilical vein endothelial cells, we will investigate endothelial differentiation and morphological organization of more undifferentiated CD34+-EPC in a coculture with hOB. Mono- and co-cultures of primary human CD34+-EPC and hOB will be analyzed in a complex, three-dimensional tissue engineering-relevant microenvironment. This will be done using RGD-coated mineralized collagen type I scaffolds to study the formation of vessel-like sprouts and differential gene expression of different angiogenic and osteogenic factors. Lentiviral transfection of hOB with a green fluorescence protein-reporter will further allow the direct visualization of cells and an accurate normalization and analysis of the gene expression in co-cultures. This study will provide insight into the cellular interactions between EPCs and hOB and help assess the significance of these cells for potential applications in bone tissue engineering and fracture healing.

• DFG Programme: Research Grants