Bioactive Seed Layer for Surface‐Confined Self‐Assembly of Peptides

Abstract

The design and control of molecular systems that self-assemble spontaneously and exclusively at or near an interface represents a real scientific challenge. We present here a new concept, an active seed layer that allows to overcome this challenge. It is based on enzyme-assisted self-assembly. An enzyme, alkaline phosphatase, which transforms an original peptide, Fmoc-FFY(PO4 (2-) ), into an efficient gelation agent by dephosphorylation, is embedded in a polyelectrolyte multilayer and constitutes the "reaction motor". A seed layer composed of a polyelectrolyte covalently modified by anchoring hydrogelator peptides constitutes the top of the multilayer. This layer is the nucleation site for the Fmoc-FFY peptide self-assembly. When such a film is brought in contact with a Fmoc-FFY(PO4 (2-) ) solution, a nanofiber network starts to form almost instantaneously which extents up to several micrometers into the solution after several hours. We demonstrate that the active seed layer allows convenient control over the self-assembly kinetics and the geometric features of the fiber network simply by changing its peptide density.

Amino Acids and Peptide‐Based Supramolecular Hydrogels for Three‐Dimensional Cell Culture

“…[75] The removal of the hydrophilic segment by enzyme-catalyzed bond cleavage can convert the precursor to hydrogelator, which can further self-assemble into hydrogels (Figure 13a). For enzyme-instructed hydrogels, precursors need to be converted into hydrogelators in the presence of an enzyme (such as phosphate, β-lactamase).…”

Supported Catalytically Active Supramolecular Hydrogels for Continuous Flow Chemistry

“…We immobilized an enzyme that is able to transform non‐self‐assembling precursors present in solution into self‐assembling building blocks on the surface . The confinement of these building blocks at the material–water interface induces the growth of nanofibers anchored on the surface and underpinning the hydrogel …”

Surface‐Assisted Self‐Assembly Strategies Leading to Supramolecular Hydrogels

“…Using alkaline phosphatase (AP) adsorbed on a surface and the Fmoc‐FFY(PO 4 2− )‐OH peptide (Y=tyrosine), Vigier‐Carrière et al. circumvented this difficulty by modifying the surface with a thin nanoarchitectured film including AP and a layer of polyelectrolytes bearing LMWH (seed layer) (Figures a,b) . AP dephosphorylates Fmoc‐FFY(PO 4 2− ) into Fmoc‐FFY‐OH, which self‐assembles at concentrations lower than the CGC for gelation in the bulk, leading to a hydrogel underpinned by a nanofiber network that evolved over time (Figure ).…”

“…b) Schematic of the nanoarchitectured film on a surface, allowing the localized enzyme‐assisted self‐assembly based on a seed layer. c) AFM images of the hydrogel formed from the surface at 120 min and 12 h. Reproduced with permission . Copyright 2015, Wiley.…”