Fig. 1
From: Protein disorder–order interplay to guide the growth of hierarchical mineralized structures
ELR spherulites and hierarchical mineralized structures. a Photograph of a transparent, robust, and flexible statherin-ELR membrane before mineralization. The membrane’s cross-section before mineralization b imaged by SEM and c histologically stained displaying a positive staining for both β-amyloid fibers and d elastin fibers with Congo Red and Elastin von Gieson stains, respectively. e SEM image of the membrane’s cross-section comprising of ELR nanofibers. f, g Polarized light microscope (PLM) images depicting the presence of ELR spherulites with the characteristic birefringent Maltese-cross pattern on the surface and within the bulk of the membranes. h-k SEM images of the top of an RGDS-ELR membrane after mineralization showing the hierarchical organization of the mineralized structures including h aligned fluorapatite nanocrystals that are i, j grouped into prism-like microstructures that further grow into k macroscopic circular structures. l, m The hierarchical structures grow until they meet each other, and n can mineralize completely thin membranes. o Rietveld refinement of an XRD pattern of mineralized membranes showing the fluorapatite nature of the crystalline phase with the typical Bragg peaks of apatite. p 19F solid-sate MAS-NMR spectra confirming the presence of fluorapatite and CaF2 (fluorite) phase at – 103 and – 108 p.p.m., respectively, with increasing fluorapatite peak intensity on the mineralized membrane (green) compared with those without the ELP membrane (red) at the same conditions. q Young’s modulus and hardness relationship between the mineralized structures and different mineralized tissues. Scale bars: a 5 mm; b 20 µm; c, d 40 µm; e 200 nm; f 10 µm; g 3 µm; h 200 nm; i 1 µm; j 10 µm; k 20 µm; l 30 µm; l (inset) 20 µm; m 5 µm; n 20 µm
