The influence of phosphorus precursor on the structure and properties of SiO ₂ –P ₂ O ₅ –CaO bioactive glass

Abstract

Bioactive glasses (BG) are one of the most promising bone regeneration materials because they can bond to bone and simulate new bone growth. Sol-gel methods for producing BG are well established, however challenges still remain in selecting and optimizing the precursors. Even for bioactive glasses with the same final composition, different precursors may lead to different structures and properties of the gel derived BG. In this work, three different phosphorus precursors, phytic acid (PA), triethyl phosphate (TEP) and n-butyl phosphate (BP) were used to prepare BG (54.2%SiO2-35%CaO-10.8%P2O5, mol. %). The obtained materials were characterized by TGA, FTIR, XRD, HEXRD, solid state 31 P, 29 Si NMR and by in vitro tests in SBF. It was found that the materials prepared by TEP or BP showed small amounts of crystallization, whereas the resulting material prepared by PA remained amorphous and had more P atoms as orthophosphate. In vitro assays indicated that all these materials were bioactive, while the BG prepared by PA showed the highest in vitro bioactivity, followed by TEP and, finally, BP. Based on these observations, it appears that phosphorus precursors have a significant impact on both the structure and bioactivity of the sol-gel derived BG. Results suggest that phytic acid should be used in preference to triethyl phosphate or n-butyl phosphate for the synthesis of sol gels. PA may improve the homogeneity of the sol gel glasses, reduce crystallization and lower stabilization temperatures.

Fe3O4/bioactive glass nanostructure: a promising therapeutic platform for osteosarcoma treatment

“…The first region is a linear curve with a sudden increase in pH to 8.8 after 24 h. The second region shows stabilized pH value. The loss of H + from the solution produces an acidic condition that helps to compensate for the pH increase caused by Ca 2+ [46] The pH changes in SBF containing 0.25Fe 3 O 4 /BG were greater (pH 8.8) compared to 0.5 (pH 8.6) and 1 (pH 8.5) Fe 3 O 4 /BG, but the difference is very small and practically negligible.…”

Phytic Acid: Properties and Potential Applications in Dentistry

“…Poly (1,8-octanediol-co-citrate) composited with PSC exhibits higher mechanical strength, bioactivity, and biocompatibility with a reduced degradation rate. It also integrated well with the surrounding tissues which would result in better bone regeneration (Ren et al, 2017). PSC/bioactive bone cement composite also showed improved injectability and maintained its shape which made it easier to manipulate during the operation (Zhu et al, 2017).…”

“…Ren et al compared the effect of three different phosphorus precursors on the bioactivity and structure of bioactive glass. It was found that the material prepared with IP6 remained amorphous with more phosphorus atoms present as orthophosphate, and also had more bioactivity compared with other phosphorus precursors (Ren et al, 2017).…”