A study of the effect of precursors on physical and biological properties of mesoporous bioactive glass

Abstract

A novel mesoporous bioactive glass (MBG) of composition 64SiO 2 -26CaO-10P 2 O 5 (mol %) was prepared by hydrothermal method using H 3 PO 4 as a precursor for P 2 O 5 . The effect of use of organic triethylphosphate (TEP) and inorganic H 3 PO 4 in MBG synthesis on glass transition temperature (T g ), crystallinity, morphology and bioactivity of MBGs was studied. Phase purity determination and structural analysis were done using powder X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy, respectively. XRD revealed that MBG prepared from H 3 PO 4 (MBG-H 3 PO 4 ) when sintered at 700°C was partially glassy/amorphous in nature and contained a mixture of crystalline apatite, wollastonite, calcium phosphate and calcium silicate phases. Calcined MBG prepared from TEP (MBG-TEP) contained only wollastonite and calcium silicate phases. Particle size and surface area determined by BET surface area analysis showed higher surface area (310 m 2 g -1 ) for MBG-H 3 PO 4 as compared to MBG-TEP (86 m 2 g -1 ). It also had a smaller particle size (20 nm) and 70 % higher pore volume (0.88 cm 3 g -1 ) for MBG-H 3 PO 4 as compared to MBG-TEP (60 nm particle size and 0.23 cm 3 g -1 pore volume). Thermal studies showed that use of H 3 PO 4 decreases T g and increased DT (difference between T g and crystallization initiation temperature Tc o ). Low T g and high DT also enhanced bioactivity of MBGs. Bioactivity was determined by immersion in a simulated body fluid for varying time intervals for a maximum period of 14 days. It revealed enhanced bioactivity, as evident by the formation of apatite layer on the surface, for MBG-H 3 PO 4 as compared to MBG-TEP. Scanning electron microscopy and FTIR spectroscopy also supported this observation. Antibacterial studies with Escherichia Coli bacteria, MBG-H 3 PO 4 showed better antibacterial behaviour than MBG-TEP.

The effect of tantalum incorporation on the physical and chemical properties of ternary silicon–calcium–phosphorous mesoporous bioactive glasses

“…Characteristic peaks located at 1038 and 1235 cm −1 are attributed to asymmetric stretching of Si‐O bond . Finally, the peak observed at 934 cm −1 is identified as Si‐NBO . From the FTIR spectra, the intensity of the stretching and bending bonds of silicon decreased with increasing tantalum content.…”

“…28 Finally, the peak observed at 934 cm −1 is identified as Si-NBO. 29 From the FTIR spectra, the intensity of the stretching and bending bonds of silicon decreased with increasing tantalum content. However, it should be noted that the intensity of the Si-NBO bond increases when 5% and higher Ta is mixed in.…”

Fabrication, in vitro and in vivo studies of bilayer composite membrane for periodontal guided tissue regeneration

“…18,19 A small band (appeared as shoulder) of Si–O–NBO (non-bridging oxygen) for Si–O–M (where M=Ca +2 ) bonds was observed around 960 cm −1 . 20 A broad band between 840 and 760 cm −1 was assigned to bending Si–O–Si mode. The O−P−Ca bond appeared at 660 cm −1 .…”

Alveolar bone repair of rhesus monkeys by using BMP-2 gene and mesenchymal stem cells loaded three-dimensional printed bioglass scaffold

“…3D-BG porous scaffold was prepared by 3D printing fiber deposition technology with BG microspheres (60% SiO 2 -36% CaO-4% P 2 O 5 , 350 nm in diameter, which was kindly provided by South China University of Technology) as printing raw materials and PVA as a binder. The scaffolds were prepared according to previously published literatures 54 . Briefly, 3D printing was performed by a 3D-Bioprinter (Envision TEC Gmb H, Germany) at room temperature to construct a cuboid BG scaffold of 10 × 7 × 5 mm with pore size of 500 um.…”