Coating with a modular bone morphogenetic peptide promotes healing of a bone-implant gap in an ovine model

PLoS One. 2012;7(11):e50378. doi: 10.1371/journal.pone.0050378. Epub 2012 Nov 21.

Abstract

Despite the potential for growth factor delivery strategies to promote orthopedic implant healing, there is a need for growth factor delivery methods that are controllable and amenable to clinical translation. We have developed a modular bone growth factor, herein termed "modular bone morphogenetic peptide (mBMP)", which was designed to efficiently bind to the surface of orthopedic implants and also stimulate new bone formation. The purpose of this study was to coat a hydroxyapatite-titanium implant with mBMP and evaluate bone healing across a bone-implant gap in the sheep femoral condyle. The mBMP molecules efficiently bound to a hydroxyapatite-titanium implant and 64% of the initially bound mBMP molecules were released in a sustained manner over 28 days. The results demonstrated that the mBMP-coated implant group had significantly more mineralized bone filling in the implant-bone gap than the control group in C-arm computed tomography (DynaCT) scanning (25% more), histological (35% more) and microradiographic images (50% more). Push-out stiffness of the mBMP group was nearly 40% greater than that of control group whereas peak force did not show a significant difference. The results of this study demonstrated that mBMP coated on a hydroxyapatite-titanium implant stimulates new bone formation and may be useful to improve implant fixation in total joint arthroplasty applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Morphogenetic Proteins / chemistry
  • Bone Morphogenetic Proteins / pharmacology*
  • Calcification, Physiologic
  • Coated Materials, Biocompatible / chemistry
  • Coated Materials, Biocompatible / pharmacology*
  • Cone-Beam Computed Tomography
  • Delayed-Action Preparations / chemistry
  • Delayed-Action Preparations / pharmacology*
  • Durapatite / chemistry
  • Female
  • Femur / surgery
  • Femur / ultrastructure*
  • Osseointegration / physiology*
  • Prostheses and Implants*
  • Sheep
  • Sheep, Domestic
  • Tensile Strength
  • Titanium / chemistry
  • Wound Healing*

Substances

  • Bone Morphogenetic Proteins
  • Coated Materials, Biocompatible
  • Delayed-Action Preparations
  • Durapatite
  • Titanium

Grants and funding

This study was funded by the Wallace H. Coulter Foundation and by the Wisconsin Alumni Research Foundation: "A Translational Research Partnership Grant from the Wallace H. Coulter Foundation" and "A Technology Accelerator Grant from the Wisconsin Alumni Research Foundation". There is no grant number from either. Smith & Nephew, Inc., provided implants for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.