Silicatein is a unique enzyme from siliceous sponges that is able to catalyze the formation of an inorganic material, silica or “biosilica” which forms the inorganic skeleton of these sponges. Another exceptional property of this protein is its dual function, as we discovered for the first time in the ERC Advanced Grant “BIOSILICA” (Grant no. 268476): silicatein both (i) acts as an enzyme (biosilica formation) and (ii) exhibits structure-forming/guiding activity. Even more important with regard to the biomedical application of silicatein: the product of the enzymatic reaction, biosilica, is osteogenic and biocompatible and allows the formation of a moldable material – the ideal basis for the potential application in bone healing, as we found. Moreover, we demonstrated that biosilica not only increases the expression of bone morphogenic protein 2 (BMP-2), but also modulates the ratio of expression of two proteins, osteoprotegerin (OPG) and RANKL, that are crucial in pathogenesis of osteoporosis. Hence, biosilica has potential in prophylaxis and therapy of osteoporosis, a major health threat worldwide. Measures to prevent the development of osteoporosis have become increasingly important due to the demographic development in many industrialized countries. Our idea arising from the ERC-funded project is to apply the silica-enzymes fused to a hydroxyapatite-binding protein tag for the formation of bioactive biosilica-based scaffold / nanocomposite materials for bone regeneration and repair in osteoporotic patients and patients with related bone diseases. The proposed project aims at bringing this idea to a pre-demonstration stage by conducting a proof of concept and verifying its innovation potential. The potential commercialization opportunities and the IPR position of this idea will be clarified.