In this study, bioactive glass particles with controllable structure and porosity were prepared using dual-templating methods. Block copolymers used as one template component produced mesopores in the calcined samples. Polymer colloidal crystals as the other template component yielded either three-dimensionally ordered macroporous (3DOM) products or shaped bioactive glass nanoparticles. The
During the last decade, the use of mesoporous materials, which have pores ranging in size from 2 to 50 nm, was proposed in tissue engineering because their large surface area and pore volume may enhance their bioactive behavior and allow them to be loaded with the osteogenic agents used to promote new bone formation [
Although all of the reported MBGs show favorable bioactivity, they are difficult to use as scaffolds for the regeneration of bone tissues at this stage because their mesosized pores are too small to promote cell growth. To overcome this pore size limitation, our group successfully prepared hierarchically structured three-dimensionally ordered macroporous (3DOM) by the sol-gel method using a block-copolymer and polymer colloidal crystals as dual templates, which can generate either three-dimensionally ordered macroporous structures or shaped bioactive glass nanoparticles.
Calcium nitrate tetrahydrate (Ca(NO3)2·4H2O), tetraethyl orthosilicate (TEOS), triethyl phosphate (TEP), the surfactant Brij 56 (C16H33(OCH2CH2)nOH,
MBGs were synthesized by a sol-gel method. In a typical synthesis of bioactive glass nanoparticles M58S (M58SP), Brij 56 was used as a structure-directing agent for the mesostructure [
Chemical compositions of MBGs (mol%).
Samples | SiO2 | CaO | P2O5 |
---|---|---|---|
M80S | 80 | 20 | — |
M70S | 70 | 30 | — |
M58S, M58SP | 60 | 36 | 4 |
The
Figure
Wide angle XRD patterns of (a) M80S, (b) M70S, and (c) M58S (symbol
EDS spectrum and the element ratio of (a) M80S, (b) M70S, and (c) M58S and (d) the percentage of element of MBGs.
Figure
SEM and TEM images of (a) M58S and (b) M58SP.
Schematic of the formation of nanoparticles through the disassembly of 3DOM structure. Copyright 2007, Wiley-VCH [
Figure
FTIR spectra of MBGs with different chemical compositions before and after soaking in SBF for 12 h.
SEM images of (a) M80S, (b) M70S, (c) M58S, and (d) M58SP after soaking in SBF for different times (0, 3, 6, 12, and 24 h).
Wide angle XRD patterns of (a) M80S, (b) M70S, (c) M58S, and (d) 58SP before and after soaking in SBF with different times (symbol
The bioactive glass skeleton with hierarchical porosity was first formed via a surfactant and polymer sphere dual-templating system, and then the three-dimensionally ordered structure was disassembled to obtain bioactive nanocubes. In addition, the study of
The authors would like to thank Walailak University Research and Development Institute, Walailak University, (Grant no. WU54203) and the National Science Foundation (DMR-0704312).