Abstract: The present invention relates to new biomimetic mineralized apatite structures. The present invention also relates to processes for the production of new biomimetic mineralized apatite structures based on natural and synthetic protein scaffolds. In particular, the invention provides synthetic crystal having a hierarchical structure formed on an elastin-like polypeptide membrane or hydrogel. The invention also provides methods of making such crystals, both in vivo and in vitro, as well as kits comprising membranes or hydrogels with cross-linking agents and/or mineralization solutions. The invention also provides the use of such structures in methods of treatment.