DMR-0454672 NIST 70NANB7H6178 NIH R01 DE016386-01

1. Dynamics and Structure of Semiflexible, Self-Assembled Peptide Chain Networks Rigid Hydrogel Unfolded peptide self assembly Fibrillar nanostructure SANS Intensity Profiles NSE: Intermediate Scattering Functions DMR-0454672 NIST 70NANB7H6178 NIH R01 DE016386-01 M.C. Branco, J.P. Schneider, D.J. Pochan, and N.J. Wagner Center for Neutron Science, University of Delaware We have engineered hydrogels comprising self assembled peptides with great potential for delivery vehicles via simple modification of the individual peptide sequence. MAX1 and MAX8 are synthetic β-hairpin peptides that undergo triggered nanoscale self-assembly to form a physically crosslinked hydrogel network of fibrils with a defined cross-section, as shown in the figure at right. 1.5 wt% MAX1 1.5 wt% MAX8 We have combined measurements using the CHRNS NSE and SANS spectrometers to yield a physical picture of the nanoscale dynamics and topology of these self-assembled peptide hydrogels, consistent with an entangled network of semiflexible fibrils. Through controlled modifications of the peptide sequence we find that both the nanoscale dynamics and the network topology itself can be altered, leading to substantial differences in bulk properties. Data analysis, using models specifically developed for semiflexible polymers, enables quantification of the nanoscale properties of these networks and the development of molecular structure-property relations. These relations enable the rational engineering of peptide hydrogels appropriate for drug delivery applications. M.C. Branco, F. Nettesheim, D.J. Pochan, J.P. Schneider, and N.J. Wagner, Biomacromolecules 2009;10(6):1374