We have used the pH-induced self-assembly of a peptide-amphiphile to make a
nanostructured fibrous scaffold reminiscent of extracellular matrix. The d
esign of this peptide-amphiphile allows the nanofibers to be reversibly cro
sslinked to enhance or decrease their structural integrity. After cross-lin
king, the fibers are able to direct mineralization of hydroxyapatite to for
m a composite material in which the crystallographic c axes of hydroxyapati
te are aligned with the tong axes of the fibers. This alignment is the same
as that observed between Collagen fibrils and hydroxyapatite crystals in b
one.