Understanding the composition-structure-bioactivity relationships in diopside (CaO·MgO·2SiO₂)-tricalcium phosphate (3CaO·P₂O₅) glass system

Acta Biomater. 2015 Mar:15:210-26. doi: 10.1016/j.actbio.2015.01.001. Epub 2015 Jan 8.

Abstract

The present work is an amalgamation of computation and experimental approach to gain an insight into composition-structure-bioactivity relationships of alkali-free bioactive glasses in the CaO-MgO-SiO2-P2O5 system. The glasses have been designed in the diopside (CaO·MgO·2SiO2; Di)-tricalcium phosphate (3CaO·P2O5; TCP) binary join by varying the Di/TCP ratio. The melt-quenched glasses have been investigated for their structure by molecular dynamic (MD) simulations as well as by nuclear magnetic resonance spectroscopy (NMR). In all the investigated glasses silicate and phosphate components are dominated by Q(2) (Si) and Q(0) (P) species, respectively. The apatite forming ability of the glasses was investigated using X-ray diffraction (XRD), infrared spectroscopy after immersion of glass powders in simulated body fluid (SBF) for time durations varying between 1 h and 14 days, while their chemical degradation has been studied in Tris-HCl in accordance with ISO 10993-14. All the investigated glasses showed good bioactivity without any substantial variation. A significant statistical increase in metabolic activity of human mesenchymal stem cells (hMSCs) when compared to the control was observed for Di-60 and Di-70 glass compositions under both basal and osteogenic conditions.

Keywords: Bioactive glasses; Diopside; Molecular dynamics simulation; Structure; Tricalcium phosphate.

Publication types

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

MeSH terms

  • Alkaline Phosphatase / metabolism
  • Calcium Phosphates / chemistry*
  • Calcium Phosphates / pharmacology*
  • Cell Differentiation / drug effects
  • Cell Shape / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Glass / chemistry*
  • Humans
  • Immunohistochemistry
  • Magnetic Resonance Spectroscopy
  • Mesenchymal Stem Cells / cytology
  • Mesenchymal Stem Cells / drug effects
  • Mesenchymal Stem Cells / metabolism
  • Mesenchymal Stem Cells / ultrastructure
  • Molecular Dynamics Simulation
  • Oxygen / chemistry
  • Silicic Acid / chemistry*
  • Silicic Acid / pharmacology*
  • Spectroscopy, Fourier Transform Infrared
  • Structure-Activity Relationship
  • X-Ray Diffraction

Substances

  • Calcium Phosphates
  • Silicic Acid
  • diopside
  • Alkaline Phosphatase
  • tricalcium phosphate
  • Oxygen