Supramolecular Polymers Explained: While polymers are constructed from chemically bonded units, supramolecular polymers arise through reversible linkages, such as hydrogen bonding and electrostatic interactions. Recent advances in the field of supramolecular polymer science have moved from a fundamental understanding of assembly properties to the introduction of functionality, in order to exploit the particular features of this class of materials. Aida et al. (p. 813 ) review the specific features of supramolecular polymers that can lead to applications in a variety of fields, including: materials—in which processability and self-healing properties are of interest; biomedicine—in which the concerns are dynamic functionality and biodegradability; and hierarchical assembly and electronic systems—with an interest in unidirectionality of charge flow.

Neural progenitor cells were encapsulated in vitro within a three-dimensional network of nanofibers formed by self-assembly of peptide amphiphile molecules. The self-assembly is triggered by mixing cell suspensions in media with dilute aqueous solutions of the molecules, and cells survive the growth of the nanofibers around them. These nanofibers were designed to present to cells the neurite-promoting laminin epitope IKVAV at nearly van der Waals density. Relative to laminin or soluble peptide, the artificial nanofiber scaffold induced very rapid differentiation of cells into neurons, while discouraging the development of astrocytes. This rapid selective differentiation is linked to the amplification of bioactive epitope presentation to cells by the nanofibers.

Peptide amphiphiles are a class of molecules that combine the structural features of amphiphilic surfactants with the functions of bioactive peptides and are known to assemble into a variety of nanostructures. A specific type of peptide amphiphiles are known to self‐assemble into one‐dimensional nanostructures under physiological conditions, predominantly nanofibers with a cylindrical geometry. The resultant nanostructures could be highly bioactive and are of great interest in many biomedical applications, including tissue engineering, regenerative medicine, and drug delivery. In this context, we highlight our strategies for using molecular self‐assembly as a toolbox to produce peptide amphiphile nanostructures and materials and efforts to translate this technology into applications as therapeutics. We also review our recent progress in using these materials for treating spinal cord injury, inducing angiogenesis, and for hard tissue regeneration and replacement. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 94:1–18, 2010.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

Twelve derivatives of peptide-amphiphile molecules, designed to self-assemble into nanofibers, are described. The scope of amino acid selection and alkyl tail modification in the peptide-amphiphile molecules are investigated, yielding nanofibers varying in morphology, surface chemistry, and potential bioactivity. The results demonstrate the chemically versatile nature of this supramolecular system and its high potential for manufacturing nanomaterials. In addition, three different modes of self-assembly resulting in nanofibers are described, including pH control, divalent ion induction, and concentration.