Abstract: An improved sol-gel process is disclosed for the making of large synthetic silica based bioactive materials objects crack-free. A series of ordered mesoporous SiO2—CaO—P2O5 sol-gel glasses which are highly bioactive are synthesized through a sol-gel process. The mesoporous glasses are highly bioactive compared with conventional ones, due to the increased textural characteristics, i.e. surface area. The bioactivity tests point out that the surface area, porosity, and 3D-structure become more important than chemical composition during the apatite crystallization stage in these materials, due to the very high textural parameters obtained. The product is intended to be used for tissue engineering applications.