Novel ion-doped mesoporous glasses for bone tissue engineering: Study of their structural characteristics influenced by the presence of phosphorous oxide.

Ion-doped binary SiO 2 -CaO and ternary SiO 2 -CaO-P 2 O 5 mesoporous bioactive glasses were synthesized and characterized to evaluate the influence of P 2 O 5 in the glass network structure. Strontium, copper and cobalt oxides in a proportion of 0.8 mol% were selected as dopants because the osteogenic and angiogenic properties reported for these elements. Although the four glass compositions investigated presented analogous textural properties, TEM analysis revealed that the structure of those containing P 2 O 5 exhibited an increased ordered mesoporosity. Furthermore, 29 Si NMR revealed that the incorporation of P 2 O 5 increased the network connectivity and that this compound captured the Sr 2 + , Cu 2 + and Co 2 + ions preventing them to behave as modifiers of the silica network. In addition, 31 P NMR results revealed that the nature of the cation directly influences the characteristics of the phosphate clusters. In this study, we have proven that phosphorous oxide entraps doping-metallic ions, granting these glasses with a greater mesopores order. [ABSTRACT FROM AUTHOR]