Aligned Assembly in a 2-D Gel of a Water-Soluble Peptide

Abstract

We demonstrate the assembly of a compact, gel-like Langmuir−Blodgett film of rods formed by self-assembly of a βsheet-forming water-soluble peptide, Ac-IKHLSVN-NH 2 , at the surface of aqueous electrolytes. We characterize surface pressure hysteresis and demonstrate shear stiffening of the surface caused by area cycling, which we interpret as due to rearrangement and alignment of the rods. We show strong effects of the electrolyte on the assembly of the elementary rods, which can be related to the Hofmeister series and interpreted by effects on the interaction energies mediated by ions and water. Formation of β-sheet structures and assembly of these into surface-segregated semicrystalline gels was strongly promoted by ammonium sulfate electrolyte. With ammonium sulfate electrolyte as subphase for Langmuir−Blodgett film deposition, shear stiffening by surface area cycling resulted in very compact films on transfer to a substrate.

Self-Assembling Hydrogel Structures for Neural Tissue Repair

“…Self-assembling fibers can be hierarchically organized in supramolecular crystals which can be aligned using various methods such as acoustic fields, pressure, magnetic fields, ultrasonication, electric fields, or external force fields. ,, For example, Zhang et al used shear force from the injection of an aqueous PA into an ionic solution to form a noodle-like hydrogel of aligned peptide nanofibers. This aligned PA was later functionalized with IKVAV and RGDS bioactive epitopes and shown to promote aligned neurite outgrowth in P19 mouse neurons .…”

Harnessing the Potential of Self‐Assembled Peptide Hydrogels for Neural Regeneration and Tissue Engineering

“…These crystals can be aligned utilizing different methods, including acoustic fields, magnetic fields, pressure, electric fields, ultrasonication, or external force fields. [131,132] In this context, scientists applied shear force generated by injecting an aqueous solution of PA in an ionic solution, leading to the formation of a hydrogel composed of aligned peptide nanofibers resembling noodles. The aligned PA hydrogel was subsequently modified with bioactive epitopes IKVAV and RGDS.…”