Abstract: A method for preparing a sol-gel derived SiO2 having a very fast bioresorption rate where a sol-gel derived SiO2 is prepared from a sol comprising water, an alkoxide or inorganic silicate and a lower alcohol using a mineral acid or a base as a catalyst and the sol is aged and dried. The method uses a pH from 1.5 to 2.5, a molar ratio of water to the alkoxide or inorganic silicate of 0.5 to 2.5, a molar ratio of alcohol to the alkoxide or inorganic silicate is ?0.5; and the sol is either let to gel without induced changes of composition and without forced drying of the sol, or a change of composition is induced; and within a time of ?30 minutes, from the induced change forced drying of the sol is carried out or initiated.

Abstract: The present invention relates to a method for preparing a sol-gel derived SiO2 with a very fast bioresorption rate wherein a sol-gel derived SiO2 is prepared from a sol comprising water, an alkoxide or inorganic silicate and a lower alcohol using a mineral acid or a base as a catalyst and said sol is aged and dried. Characteristic for the method is that pH is from 1.5 to 2.5, molar ratio of water to the alkoxide or inorganic silicate is 0.5 to 2.5, of alcohol to the alkoxide or inorganic silicate is ?0.5; and the sol is either let to gel without induced changes of composition and without forced drying of the sol, or a change of composition are induced; and within a time of ?30 minutes, from the induced change forced drying of the sol is carried out or initiated. The present invention also relates to a method for adjusting the bioresorption rate of sol-gel derived SiO2.