title: Co-transplantation of endothelial progenitor cells and mesenchymal stem cells promote neovascularization and bone regeneration.
abstract: BACKGROUND
  Bone formation relies on sufficient blood supply and osteoprogenitor cells.
  
  
  OBJECTIVE
  The study aims to evaluate the influence of endothelial progenitor cells (EPCs) in combination with mesenchymal stem cells (MSCs) on early vascularization and intramembranous bone regeneration.
  
  
  METHODS
  Vertical bone regeneration was tested in rat calvarium guided bone regeneration model. Gold domes were filled with a mixture of 5 × 10(5) osteogenic transformed MSC and 5 × 10(5) EPC (EPC/MSC) that were mixed with β-tricalcium phosphate (βTCP) scaffold. Domes filled with βTCP alone served as control. Rats were sacrificed after 4 or 12 weeks. Histomorphometry was used to determine blood vessel (Bv) density, vertical bone height, and bone area in the regenerated tissue.
  
  
  RESULTS
  At both time points, new augmented hard tissue filled the space under the dome, and Bv density was higher in the EPC/MSC transplanted group vs control. However, bone height and bone area were similar among the groups 4 weeks posttransplantation, but were doubled in the EPC/MSC transplanted group 12 weeks posttransplantation.
  
  
  CONCLUSIONS
  EPC/MSC transplantation increases Bv formation in the early stages of healing that precedes enhancement of extracortical bone regeneration in later stages.
authors.affiliation: Department of Periodontology, School of Graduate Dentistry, Rambam Health Care Campus, Haifa, Israel; Research Institute for Bone Repair, Rambam Health Care Campus, Haifa, Israel; The Rappaport Family Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.
authors.forename: Hadar
authors.initials: H
authors.lastname: Zigdon-Giladi
authors.forename: Tova
authors.initials: T
authors.lastname: Bick
authors.forename: Dina
authors.initials: D
authors.lastname: Lewinson
authors.forename: Eli E
authors.initials: EE
authors.lastname: Machtei
mesh_terms: D000818:Animals; D002130:Calcium Phosphates; D066026:Endothelial Progenitor Cells / Q000637:transplantation*; D045164:Mesenchymal Stem Cell Transplantation; D018919:Neovascularization, Physiologic / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology*; D051381:Rats; D012886:Skull / Q000601:surgery*; D013524:Surgical Flaps; D054457:Tissue Scaffolds
chemical_list: D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate
keywords: bone regeneration; bone tissue engineering; cell therapy; endothelial progenitor cells; mesenchymal stem cells; neovascularization