Bone marrow stromal cells with a combined expression of BMP-2 and VEGF-165 enhanced bone regeneration

Biomed Mater. 2011 Feb;6(1):015013. doi: 10.1088/1748-6041/6/1/015013. Epub 2011 Jan 21.

Abstract

Bone graft substitutes with osteogenic factors alone often exhibit poor bone regeneration due to inadequate vascularization. Combined delivery of osteogenic and angiogenic factors from biodegradable scaffolds may enhance bone regeneration. We evaluated the effects of bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor (VEGF), combined with natural coral scaffolds, on the repair of critical-sized bone defects in rabbit orbits. In vitro expanded rabbit bone marrow stromal cells (BMSCs) were transfected with human BMP2 and VEGF165 genes. Target protein expression and osteogenic differentiation were confirmed after gene transduction. Rabbit orbital defects were treated with a coral scaffold loaded with BMP2-transduced and VEGF-transduced BMSCs, BMP2-expressing BMSCs, VEGF-expressing BMSCs, or BMSCs without gene transduction. Volume and density of regenerated bone were determined by micro-computed tomography at 4, 8, and 16 weeks after implantation. Neovascularity, new bone deposition rate, and new bone formation were measured by immunostaining, tetracycline and calcein labelling, and histomorphometric analysis at different time points. The results showed that VEGF increased blood vessel formation relative to groups without VEGF. Combined delivery of BMP2 and VEGF increased new bone deposition and formation, compared with any single factor. These findings indicate that mimicking the natural bone development process by combined BMP2 and VEGF delivery improves healing of critical-sized orbital defects in rabbits.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anthozoa
  • Bone Marrow Cells / physiology*
  • Bone Morphogenetic Protein 2 / genetics*
  • Bone Morphogenetic Protein 2 / physiology*
  • Bone Regeneration / genetics*
  • Bone Regeneration / physiology*
  • Bone Substitutes
  • Cell Differentiation
  • Cell Proliferation
  • Cells, Cultured
  • Female
  • Humans
  • Neovascularization, Physiologic
  • Orbital Fractures / pathology
  • Orbital Fractures / therapy
  • Osteogenesis / genetics
  • Osteogenesis / physiology
  • Rabbits
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Stromal Cells / physiology
  • Tissue Engineering
  • Tissue Scaffolds*
  • Transduction, Genetic
  • Vascular Endothelial Growth Factor A / genetics*
  • Vascular Endothelial Growth Factor A / physiology*
  • X-Ray Microtomography

Substances

  • BMP2 protein, human
  • Bone Morphogenetic Protein 2
  • Bone Substitutes
  • Recombinant Proteins
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A