Fabrication of self-assembling D-form peptide nanofiber scaffold d-EAK16 for rapid hemostasis.

We previously reported a class of designer self-assembling peptides that form 3-dimensional nanofiber scaffolds using only l-amino acids. Here we report that using d-amino acids, the chiral self-assembling peptide d-EAK16 also forms 3-dimensional nanofiber scaffold that is indistinguishable from its counterpart l-EAK16. These chiral peptides containing all d-amino acids, d-EAK16, self-assemble into well-ordered nanofibers. However with alternating d- and l-amino acids, EAK16 and EAK16, showed poor self-assembling properties. To fully understand individual molecular building blocks and their structures, assembly properties and dynamic behaviors for rapid hemostasis, we used circular dichroism, atomic force microscopy and scanning electron microscopy to study in detail the peptides. We also used rheological measurement to study the hydrogel gelation property. Furthermore, we used an erythrocyte-agglutination test and a rabbit liver wound healing model, particularly in the transverse rabbit liver experiments, to examine rapid hemostasis. We showed that 1% d-EAK16 for the liver wound hemostasis took ∼20 s, but using 1% of EAK16 and EAK16 that have alternating chiral d- and l-amino acids took ∼70 and ∼80 s, respectively. We here propose a plausible model not only to provide insights in understanding the chiral assembly properties for rapid hemostasis, but also to aid in further design of self-assembling d-form peptide scaffolds for clinical applications.