A new bone-inducing biodegradable porous beta-tricalcium phosphate

J Biomed Mater Res A. 2004 Sep 1;70(3):450-8. doi: 10.1002/jbm.a.30102.

Abstract

A new type of degradable biomaterial with bone-inducing capacity was made by combining porous beta-tricalcium phosphate (beta-TCP) with a delivery system for recombinant human bone morphogenetic protein-2 (rhBMP-2). The BMP delivery system consisted of a block copolymer composed of poly-D,L-lactic acid with random insertion of p-dioxanone and polyethylene glycol (PLA-DX-PEG), a known biocompatible and biodegradable material. The efficacy of this biomaterial in terms of its bone-inducing capacity was examined by ectopic bone formation in the dorsal muscles of the mouse. In the beta-TCP implants coated with the PLA-DX-PEG polymer containing more than 0.0025% (w/w) of rhBMP-2, new ectopic bone tissues with marrow were consistently found on the surface of implants. The radiographic density of beta-TCP was diminished in a time-dependent manner. On histological examination, numerous multinucleated osteoclasts with positive tartrate-resistant acid-phosphatase (TRAP) staining were noted on the surface of the beta-TCP. These experimental results indicate that beta-TCP implants coated with synthetic rhBMP-2 delivery system might provide effective artificial bone-graft substitutes with osteoinductive capacity and biodegradable properties. In addition, this type of biomaterial may require less rhBMP-2 to induce significant new bone mass.

MeSH terms

  • Absorbable Implants*
  • Acid Phosphatase / metabolism
  • Animals
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins / chemistry
  • Bone Morphogenetic Proteins / genetics
  • Bone Morphogenetic Proteins / metabolism
  • Bone Regeneration / physiology*
  • Bone and Bones / cytology
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / pathology
  • Calcium Phosphates / chemistry*
  • Calcium Phosphates / metabolism*
  • Coated Materials, Biocompatible / chemistry*
  • Coated Materials, Biocompatible / metabolism
  • Dioxanes / chemistry
  • Drug Delivery Systems
  • Humans
  • Isoenzymes / metabolism
  • Lactic Acid / chemistry
  • Male
  • Mice
  • Mice, Inbred Strains
  • Microscopy, Electron, Scanning
  • Polyesters
  • Polyethylene Glycols / chemistry
  • Polymers / chemistry
  • Radiography
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Surface Properties
  • Tartrate-Resistant Acid Phosphatase
  • Time Factors
  • Transforming Growth Factor beta / chemistry
  • Transforming Growth Factor beta / genetics
  • Transforming Growth Factor beta / metabolism

Substances

  • BMP2 protein, human
  • Bmp2 protein, mouse
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins
  • Calcium Phosphates
  • Coated Materials, Biocompatible
  • Dioxanes
  • Isoenzymes
  • Polyesters
  • Polymers
  • Recombinant Proteins
  • Transforming Growth Factor beta
  • beta-tricalcium phosphate
  • recombinant human bone morphogenetic protein-2
  • Lactic Acid
  • Polyethylene Glycols
  • poly(lactide)
  • Acid Phosphatase
  • Acp5 protein, mouse
  • Tartrate-Resistant Acid Phosphatase
  • 4-dioxanone