Xenotransplantation of Human Umbilical Cord Perivascular Cells in a Femoral Defect

This work examines the osteogenic potential and immune-privileged properties of human umbilical cord perivascular cells (HUCPVCs) in normal Wistar rats and athymic rnu/rnu rats for up to 60 days. HUCPVCs demonstrated a mesenchymal stromal cell phenotype, assayed through flow cytometry, and RT-PCR analysis detected their expression of osteogenic genes. A bone tissue engineering construct was developed through centrifugal seeding of HUCPVCs onto calcium phosphate-coated PLGA scaffolds. These cell-scaffold constructs were transplanted into bilateral femoral defects. HUCPVCs did not induce any systemic biological response in normal rats; however, they did not engraft and impaired bone healing up to 60 days. When transplanted into athymic rats, HUCPVCs were detected up to 30 days in the femoral defects, improved bone regeneration at 15 and 30 days, as measured by micro computed tomography, and expressed osteogenic proteins. These findings demonstrate that HUCPVCs are suitable for bone tissue engineering studies in larger animals.MAS