The course of evolution in nature endows some organisms with distinguished ability of constructing complex inorganic structures that have intricate and multi-scale ordered structures, special functionalities and species-specific genetic characteristics. Therefore, learning from nature and biomimetic mineralization become one of important approaches to advanced materials. Research on the biomineralization indicate that certain biomolecules play a key important role during the biosilica formation. For example, silaffins and long chain polyamine extracted from diatom and silicateins from sponges, control the nucleation and growth of silicious species at a molecular level by manipulating the interfacial interactions between organic molecules and inorganic species, and therefore result in the generation of biosilica with organized hierarchical structures. Simulating the biomineralization process, people have prepared silica nanomaterials with various morphologies, structures and properties based on the designed organic molecules during the recent decades. In this review, four sections are involved. Firstly, we introduce the results about the formation mechanism of biosilica including the identification of bioextracts and their functions, catalyzing and stabilizing mechanisms, morphology generation of biosilica. Secondly but importantly, we review the recent progress in biomimetic synthesis of silica. This content can also be divided into four units, bioextracts regulating biosilicification, artificial synthetic molecules mediating mineralization, external forces driving morphogenesis and tools in biomimetic mineralization. Thirdly, we introduc the potential application of biomimeticly synthesized silica in cell culture, drug and gene delivery system, catalysis, separation and detection, protecting biomolecules and functional materials construction. Finally, we point out the problems of the present researches and give some resolution, and then present some likely main research direction in this field.

Contents
1 Introduction
2 Biomineralizing mechanisms
2.1 Extracts from biosilica
2.2 Catalyzing mechanism of organic molecules
2.3 Stabilizing mechanism of organic molecules
2.4 Regulation on structures and morphologies of silica
3 Biomimetic synthesis and structure regulation of silica
3.1 Biomimetic mineralization templated by bioextracts
3.2 Biomimetic mineralization mediated by artificial synthetic molecules
3.3 Environmental effects on biomimetic mineralization
3.4 Tools in biomimetic mineralization
4 Application of the biomimeticly synthesized silica
4.1 Scaffolds for cell culture
4.2 Separation, gene and drug delivery
4.3 Protection for biomolecules and catalytic center
4.4 Preparation of functional materials and catalysis
5 Problems and outlook