Synthesis, characterization and bioactivity of bioglasses in the Na₂O-CaO-P₂O₅-SiO₂ system prepared via sol gel processing

Different kinds of bioactive materials are used as bone substitutes. In particular, bioglasses containing Si, Ca, Na and P, bind to host tissues with a stable chemical bond. The phenomenon of bioactivity is associated with the formation of a crystallized hydroxycarbonated apatite (HCA) layer on the bioglass surface, when soaked in a simulated physiological fluid. This layer is similar to the mineral phase of bone.Synthesized bioglasses have been obtained using organic modifiers instead of mineral modifiers, which are the usual precursors for sol-gel synthesis.First, a slightly soluble ternary glass, containing 48% CaO, 5% P₂O₅ and 47% SiO₂, referred to as Si47P5T, was prepared.Then, some sodium oxide has been added to obtain a more bioactive quaternary bioglass, containing 21.5% Na₂O, 26.5% CaO, 5% P₂O₅ and 47% SiO₂ which is referred to as Si47P5Q.Physicochemical properties of both bioglasses have been studied. Bioactivity in a simulated body fluid (SBF) and cytotoxicity tests have complemented the study.