Self-Assembling Peptide Amphiphiles

Northwestern researchers have created self-assembling peptide amphiphiles that form nanofibers. A crosslinking functionality can be added to this supramolecular structure to enhance the overall rigidity, resulting in the formation of a more robust material. Dr. Stupp's lab has previously developed numerous peptide amphiphiles (PAs) that self-assemble into micro-long nanofibers, driven primarily by hydrophobic forces and beta-sheet formation. An additional modification to these peptide amphiphiles was added, to enable crosslinking functionality while still maintaining the monomer's ability to self-assemble into nanofibers. The addition of the diacetylene crosslinker into the alkyl tail region of the monomer exhibits polymerization along the z-axis of the fiber. By crosslinking a self-assembled supramolecular structure and maintaining the self-assembled structure, this resulted in the creation of stiffer, self-supporting hydrogels. In comparison to the non-polymerized peptide amphiphiles which form weak gels that cannot withstand physical manipulation, the polymerized PAs can be physically manipulated without breaking its hydrogel form. There has been much interest in the development of bioactive tissue scaffolds that can be implanted into an injured area, in order to enhance healthy tissue regeneration. Previous studies of bioactive peptide amphiphiles have already suggested promising results as tissue scaffolds, however delivery of the scaffolds to the surgical location has been challenging due to the mechanical nature of the weak PA hydrogel. The design of diacetylene peptide amphiphiles, as a more robust material once polymerized, will be significant for such biological and medicinal purposes. Applications o Bioactive tissue scaffolds for tissue implantation Advantages o More robust scaffold IP Status Patent applications have been filed.