Augmentation of osseous phenotypes in vivo with a synthetic peptide

J Orthop Res. 2007 Apr;25(4):531-9. doi: 10.1002/jor.20303.

Abstract

The synthetic peptide B2A2-K-NS augmented the in vitro expression of osseous phenotypes when cells were stimulated with BMP-2, an osteoinductive growth factor. B2A2-K-NS significantly enhanced the effects of BMP-2-induced alkaline phosphatase activity and mineralization. In the absence of BMP-2, B2A2-K-NS did not have an effect on these endpoints. Based on these observations, in vivo studies were conducted to evaluate if B2A2-K-NS could augment osseous phenotypes in an osteoinductive environment in which BMP-2 should be present. In one study, human demineralized bone matrix (DBM) was used to generate an osteoinductive environment and the effects of B2A2-K-NS on ectopic mineralization of subcutaneous implants evaluated. In the second study, a noncritical sized defect in rabbit ulnas with inherent reparative capacity was used as the osteoinductive environment and was treated with or without B2A2-K-NS. In the DBM studies, B2A2-K-NS augmented mineralization as determined using a combination of radiographic analysis and von Kossa staining at 4 weeks postimplant. In the rabbit ulna model, B2A2-K-NS significantly increased the radiographic bone density in the defects compared to carrier-only or no-treatment controls after 6 weeks. Histological staining confirmed that B2A2-K-NS generated a pronounced bone repair response. The results are consistent with the hypothesis that B2A2-K-NS augments osseous phenotypes in an osteoinductive environment, and suggests that B2A2-K-NS may have clinical utility.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alkaline Phosphatase / metabolism
  • Animals
  • Bone Matrix / drug effects
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins / pharmacology*
  • Bone Regeneration / drug effects
  • Calcification, Physiologic / drug effects
  • Cell Line
  • Choristoma / metabolism
  • Choristoma / pathology
  • Humans
  • Intercellular Signaling Peptides and Proteins
  • Male
  • Mice
  • Osteoblasts / drug effects
  • Osteogenesis / drug effects*
  • Peptides / pharmacology*
  • Phenotype
  • Pluripotent Stem Cells / drug effects
  • Rabbits
  • Radiography
  • Rats
  • Rats, Nude
  • Transforming Growth Factor beta / pharmacology*
  • Ulna / diagnostic imaging
  • Ulna / drug effects

Substances

  • B2A2-K-NS
  • BMP2 protein, human
  • Bmp2 protein, mouse
  • Bmp2 protein, rat
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins
  • Intercellular Signaling Peptides and Proteins
  • Peptides
  • Transforming Growth Factor beta
  • Alkaline Phosphatase