Ectopic bone formation in rat marrow stromal cell/titanium fiber mesh scaffold constructs: effect of initial cell phenotype

Biomaterials. 2005 Nov;26(31):6208-16. doi: 10.1016/j.biomaterials.2005.04.006.

Abstract

Titanium fiber mesh scaffolds have been shown to be a suitable material for culture of primary marrow stromal cells in an effort to create tissue engineered constructs for bone tissue replacement. In native bone tissue, these cells are known to attach to extracellular matrix molecules via integrin receptors for specific peptide sequences, and these attachments can be a source of cell signaling, affecting cell behaviors such as differentiation. In this study, we examined the ability of primary rat marrow stromal cells at two different stages of osteoblastic differentiation to further differentiate into osteoblasts both in vitro and in vivo when seeded on titanium fiber mesh scaffolds either with or without RGD peptide tethered to the surface. In vitro, the tethered RGD peptide resulted in reduced initial cell proliferation. In vivo, there was no effect of tethered RGD peptide on ectopic bone formation in a rat subcutaneous implant model. Scaffold/cell constructs exposed to dexamethasone for 4 days prior to implantation (+dex constructs) resulted in significant bone formation whereas no bone formation was observed in--dex constructs. These results show that the osteoblastic differentiation of marrow stromal cells was not dependent on surface tethered RGD peptide, and that the initial differentiation stage of implanted cells plays an important role in bone formation in titanium fiber mesh bone tissue engineering constructs.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Bone Marrow Cells / cytology*
  • Bone Marrow Cells / drug effects
  • Bone Marrow Cells / physiology
  • Cell Differentiation / drug effects
  • Cell Differentiation / physiology
  • Cells, Cultured
  • Coated Materials, Biocompatible / chemistry
  • Coated Materials, Biocompatible / pharmacology
  • Materials Testing
  • Oligopeptides / chemistry
  • Oligopeptides / pharmacology*
  • Osteoblasts / cytology*
  • Osteoblasts / drug effects
  • Osteoblasts / physiology
  • Osteogenesis / physiology*
  • Phenotype
  • Rats
  • Stem Cells / cytology*
  • Stem Cells / drug effects
  • Stem Cells / physiology
  • Stromal Cells / cytology
  • Stromal Cells / drug effects
  • Stromal Cells / physiology
  • Tissue Engineering / methods
  • Titanium / chemistry*

Substances

  • Coated Materials, Biocompatible
  • Oligopeptides
  • arginyl-glycyl-aspartic acid
  • Titanium