Tunable Macroscopic Alignment of Self-Assembling Peptide Nanofibers.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Tissue Engineering

Background:

• Self-assembling systems enable nanoscale geometries like fibers and sheets.
• Controlling nanoscale organization within macroscopic structures remains a challenge.

Purpose of the Study:

• To present a facile extrusion-based method for fabricating anisotropic, nanofibrous hydrogels.
• To demonstrate control over nanostructure and macrostructure in self-assembling peptide hydrogels.
• To investigate the impact of nanostructural anisotropy on hydrogel properties and cell interactions.

Main Methods:

• Utilized an extrusion-based fabrication method with shear force and ion-triggered gelation.
• Employed self-assembling peptides to form supramolecular nanofibers.
• Modulated phosphate buffer concentration to tune hydrogel nanostructure.
• Investigated cell spreading and alignment on anisotropic hydrogels.

Main Results:

• Successfully produced aligned, hierarchical macrostructures from self-assembling peptide nanofibers.
• Demonstrated tunability of hydrogel nanostructure and anisotropy.
• Found that increased nanostructural anisotropy enhances hydrogel strength and stiffness.
• Observed directional cell spreading on aligned hydrogels, but noted complex cell-matrix interactions impacting alignment.

Conclusions:

• Developed a method to decouple nanostructure from macrostructure in self-assembling peptide hydrogels.
• Highlighted the importance of multi-length scale control for biomaterial applications.
• Suggested that mechanical coupling is crucial for cells to perceive nanofibrous alignment cues.
• Anticipate broad applications in bottom-up tissue engineering and regenerative medicine.