Biologically mediated resorption of brushite cement in vitro

Biomaterials. 2006 Apr;27(10):2178-85. doi: 10.1016/j.biomaterials.2005.11.012. Epub 2005 Dec 6.

Abstract

A new calcium phosphate cement is reported, which sets to form a matrix consisting of brushite, dicalcium pyrophosphate dihydrate and an amorphous phase following the mixture of beta-tricalcium phosphate with an aqueous pyrophosphoric acid solution. This reactant combination set within a clinically relevant time-frame (approximately 10 min) and exhibited a higher compressive strength (25 MPa) than previously reported brushite cements. The in vitro degradation of the beta-tricalcium phosphate-pyrophosphoric acid cement was tested in both phosphate buffered saline and bovine serum. The pyrophosphate ion containing cement reported here was found not to be hydrolysed to form hydroxyapatite in vitro like beta-tricalcium phosphate-orthophosphoric acid solution cements. This finding is significant since the formation of hydroxyapatite by hydrolysis is thought to retard in vivo degradation of brushite cements. When aged in bovine serum, the cement lost considerably more mass than when aged in phosphate buffered saline, indicating that proteins, most likely phosphatase enzymes played an important role in the degradation. As pyrophosphate ions are thought to be the source of orthophosphate ions during bone mineralisation, this new class of bone cement offers a route to new degradable synthetic bone grafting materials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials* / chemistry
  • Biocompatible Materials* / metabolism
  • Bone Cements* / chemistry
  • Bone Cements* / metabolism
  • Calcium Phosphates* / chemistry
  • Calcium Phosphates* / metabolism
  • Cattle
  • Compressive Strength
  • Humans
  • Materials Testing
  • Phosphoric Acids / chemistry
  • Phosphoric Acids / metabolism
  • Porosity
  • Spectroscopy, Fourier Transform Infrared

Substances

  • Biocompatible Materials
  • Bone Cements
  • Calcium Phosphates
  • Phosphoric Acids
  • beta-tricalcium phosphate
  • calcium phosphate, dibasic, dihydrate