Fast Self‐Assembly Dynamics of a β‐Sheet Peptide Soft Material

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 19; no. 20; pp. e2206795 - n/a
• Main Authors: Bertouille, Jolien, Kasas, Sandor, Martin, Charlotte, Hennecke, Ulrich, Ballet, Steven, Willaert, Ronnie G.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.05.2023
• Subjects: Biocompatibility; Biomedical materials; Drug Delivery Systems; high‐speed atomic force microscopy; Hydrogels; Liquid-solid interfaces; Microscopy, Atomic Force; Morphology; Nanostructured materials; Nanostructures - chemistry; Nanotechnology; peptide hydrogels; Peptides; Peptides - chemistry; Physical properties; Protein Conformation, beta-Strand; Self-assembly; self‐assembly pathways; solid–liquid interfaces; Tissue engineering; Wound healing; solid-liquid interfaces; high-speed atomic force microscopy; peptide hydrogels; self-assembly pathways
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202206795

Peptide‐based hydrogels are promising biocompatible materials for wound healing, drug delivery, and tissue engineering applications. The physical properties of these nanostructured materials depend strongly on the morphology of the gel network. However, the self‐assembly mechanism of the peptides that leads to a distinct network morphology is still a subject of ongoing debate, since complete assembly pathways have not yet been resolved. To unravel the dynamics of the hierarchical self‐assembly process of the model β‐sheet forming peptide KFE8 (Ac‐FKFEFKFE‐NH2), high‐speed atomic force microscopy (HS‐AFM) in liquid is used. It is demonstrated that a fast‐growing network, based on small fibrillar aggregates, is formed at a solid–liquid interface, while in bulk solution, a distinct, more prolonged nanotube network emerges from intermediate helical ribbons. Moreover, the transformation between these morphologies has been visualized. It is expected that this new in situ and in real‐time methodology will set the path for the in‐depth unravelling of the dynamics of other peptide‐based self‐assembled soft materials, as well as gaining advanced insights into the formation of fibers involved in protein misfolding diseases. The dynamics of the self‐assembly of the model peptide KFE8 at high spatial and temporal resolution in native conditions using AFM are visualized. The fast dynamics of growing peptide fibrils attached to a mica substrate as well as the slower formation of a helical ribbon structure and its conversion to a nanotube in bulk solution is successfully recorded.