Calcium silicate hydrate (C-S-H) is the binding component of concrete, the most widely used synthetic material in the world. The main disadvantage of concrete is its lack of elasticity and low flexural strength, which greatly limits its potential, making the use of steel reinforcement necessary. Although the properties of C-S-H can be significantly improved by creating organic hybrids, the full potential of this approach cannot be realized due to the disordered nanoplatelet structure of C-S-H. A biotechnological approach to create a mesocrystal from highly ordered C-S-H nanoplatelets, the gaps between which are filled with a polymeric binder, similar to the way a sea urchin’s backbone is composed of highly ordered nanoparticles in a biomineral mesocrystal, is proposed. The developed material has a bending strength characteristic of nacre, and surpasses all currently known C-S-H-based materials in this respect. This nano-scale approach could be of significant benefit to construction technology in the future, as it can significantly increase the impact strength and ductility of brittle cementitious materials.