title: An emerging cell-based strategy in orthopaedics: endothelial progenitor cells.
abstract: OBJECTIVE
  The purpose of this article was to analyze the results of studies in the literature, which evaluated the use of endothelial progenitor cells (EPCs) as a cell-based tissue engineering strategy.
  
  
  METHODS
  EPCs have been successfully used in regenerative medicine to augment neovascularization in patients after myocardial infarction and limb ischemia. EPCs' important role as vasculogenic progenitors presents them as a potential source for cell-based therapies to promote bone healing.
  
  
  RESULTS
  EPCs have been shown to have prominent effects in promoting bone regeneration in several animal models. Evidence indicates that EPCs promote bone regeneration by stimulating both angiogenesis and osteogenesis through a differentiation process toward endothelial cell lineage and formation of osteoblasts. Moreover, EPCs increase vascularization and osteogenesis by increased secretion of growth factors and cytokines through paracrine mechanisms.
  
  
  CONCLUSIONS
  EPCs offer the potential to emerge as a new strategy among other cell-based therapies to promote bone regeneration. Further investigations and human trials are required to address current questions with regard to biology and mechanisms of action of EPCs in bone tissue engineering.
authors.affiliation: Musculoskeletal Research Laboratory, Division of Orthopaedic Surgery, St. Michael's Hospital, University of Toronto, 55 Queen St. E., Suite 800, Toronto, ON, M5C 1R6, Canada. Kivanc.Atesok@utoronto.ca
authors.forename: Kivanc
authors.initials: K
authors.lastname: Atesok
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Jon
authors.initials: J
authors.lastname: Karlsson
authors.forename: Takayuki
authors.initials: T
authors.lastname: Asahara
authors.forename: Anthony
authors.initials: A
authors.lastname: Atala
authors.forename: M Nedim
authors.initials: MN
authors.lastname: Doral
authors.forename: Rene
authors.initials: R
authors.lastname: Verdonk
authors.forename: Ru
authors.initials: R
authors.lastname: Li
authors.forename: Emil
authors.initials: E
authors.lastname: Schemitsch
mesh_terms: D000818:Animals; D001861:Bone Regeneration; D001842:Bone and Bones / Q000098:blood supply; D002454:Cell Differentiation; D002465:Cell Movement; D049109:Cell Proliferation; D042783:Endothelial Cells / Q000166:cytology*; D004921:Erythropoietin / Q000502:physiology; D017102:Fracture Healing; D006801:Humans; D059630:Mesenchymal Stem Cells; D018919:Neovascularization, Physiologic; D009569:Nitric Oxide / Q000502:physiology; D010006:Osteoblasts; D010012:Osteogenesis; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology*; D023822:Tissue Engineering; D042442:Vascular Endothelial Growth Factors / Q000502:physiology
chemical_list: D042442:Vascular Endothelial Growth Factors; D004921:Erythropoietin; D009569:Nitric Oxide