Pure and mineralized collagen fibrils.

<p>(A) SEM and TEM image of non-crosslinked collagen fibrils showing their native banding patterns. (B) SEM image of non-crosslinked collagen fibrils after mineralization appearing a filamentous substructure. D-banding can be only observed on areas without subfibrillar structure. SEM (C) and AFM (D) image of crosslinked collagen fibrils with native banding patterns. Dotted line in (C) marks the width of a single collagen fibril. The microfibrillar structure is visible with careful observation on the AFM image in (D). (E) (F) and (G) SEM images of crosslinked collagen fibrils after mineralization composed of bundles of subfibrils. (H) A cross-sectional view of crosslinked collagen fibrils after mineralization. Dashed circles in (F) and (H) mark the outer edges of the individual MCFs. Dotted line in G marks the width of a MCF. Some of the multiple subfibrils are pointed by arrows in (E) and (H).