In situ SAXRD study of sol-gel induced well-ordered mesoporous bioglasses for drug delivery

J Biomed Mater Res A. 2008 Jun 15;85(4):1032-42. doi: 10.1002/jbm.a.31545.

Abstract

In this work, two systems of mesoporous bioglasses (MBGs) were sol-gel derived using block copolymer pluronic F127 and P123, respectively, as templates. A two-dimensional hexagonal (P6mm) mesoporous structure was obtained for the two systems, with d-spacing in (100) reflection of 8.49 nm for P123-templated MBG (P123-MBG) and 10.26 nm for F127-templated MBG (F127-MBG). The phase transformation behavior for the systems was elucidated using an in situ synchrotron small angle X-ray diffraction approach, with the corresponding mechanisms proposed. It was indicated that both systems go through a complicated phase transformation, from a disordered to a finely ordered hexagonal structure during the self-evaporation process. The surfactants not only acted as templates for the ordered structure, but also enhanced the rigidity of Si-O network, which prevented disruption to the ordered Si-O arrangement by the Ca(2+) and P-O group. In vitro bioactivity study showed similar bioactivity for both the P123-MBG and F127-MBG systems. Drug loading and release studies using a model metoclopramide drug showed that both MBGs presented better loading and release compared to normal bioglass (BG). The significantly higher loading and better sustained release for P123-MBG, compared to F127-MBG, is attributed to its higher pore volume and surface area.

MeSH terms

  • Apatites / chemistry
  • Ceramics / chemistry*
  • Drug Delivery Systems*
  • Gels / chemistry*
  • Metoclopramide / administration & dosage*
  • Microscopy, Electron, Transmission
  • Porosity
  • Scattering, Small Angle*
  • Spectroscopy, Fourier Transform Infrared
  • X-Ray Diffraction*

Substances

  • Apatites
  • Bioglass
  • Gels
  • Metoclopramide