Fig. 6. Peptides as biomineralization scaffolds and organic–inorganic composite agents.

a | Self-assembled peptides can serve as templates for the deposition of inorganic materials. b | For example, Fmoc-protected 3,4-dihydroxy-L-phenylalanine dipeptide affords a hydrogel that reduces Ag⁺ ions over 3 days to give Ag crystals, as evidenced in transmission electron micrographs²²¹. c | Scanning electron micrographs of mineralized bone-like nodules on nanofibres of a glycosaminoglycan-mimicking peptide⁵⁷. d | Cryogenic transmission electron microscopy and selected-area electron diffraction (SAED) of hydroxyapatite mineralized at amphiphilic peptides. Black and white arrows indicate the location of the organic template and the position of inorganic crystals, respectively. SAED arrows indicate the oriented (002) reflection (1: (002), 2: {211}, 3: (004))²⁰⁸. e | Formation of SiO₂ nanoparticles directed by self-assembled silaffin R5 peptide structures²⁰⁹. Part b adapted with permission from REF.²²¹, American Chemical Society (https://pubs.acs.org/doi/10.1021/nn502240r). Part c adapted with permission from REF.⁵⁶, Elsevier. Part d adapted with permission from REF.²⁰⁸, Wiley. Part e adapted with permission from REF.²⁰⁹, Wiley.