Hydrogelation Induced by Fmoc-Protected Peptidomimetics

Abstract

Four new low molecular weight hydrogelators (LMWGs) have been prepared in multigram scale and their attitude to form hydrogels has been tested. The gelation trigger is pH variation. The resulting gels have been characterized with several techniques: measurement of the melting points (T(gel)), transparency, gelation time, and viscoelastic properties, together with ECD analysis. Among them, Fmoc-L-Tyr-D-Oxd-OH 1 is an excellent gelator that leads to the preparation of strong, transparent, and viscoelastic gels, by pH variation. UV-visible analyses have demonstrated that the gels obtained with the LMWG 1 possess high transparency, with a transmittance up to 25.6% at a wavelength of 600 nm. Results of the amplitude sweep experiments showed that the elastic response component (G') was approximately an order of magnitude larger than the viscous component, indicating an elastic rather than viscous attitude of the gels, confirmed by the frequency independence of G' and G″ values, in the range from 0.1 to 100 rad·s(-1). The thermal behavior of gel obtained from Fmoc-L-Tyr-D-Oxd-OH 1 was characterized performing an "ad hoc" rheological temperature sweep experiment, that indicated that G' remained almost constant from 23 °C up to about 65 °C while G″ increased in the same temperature range. At higher temperatures, both G' and G″ values started to slightly decrease without displaying a crossover point.

Pseudopeptide‐Based Hydrogels Trapping Methylene Blue and Eosin Y

“…[19] These molecules cause al ocal constraint in the pseudopeptide chain that favours the formationo fs econdary structures, [20][21][22] fibers [23][24][25] and gels. [26][27][28] Thus we prepared hydrogels based on Fmoc-l-Phe-d-pGlu-OH to test them for the adsorptiono fM ethylene Blue (MB), ac ationic dye, and Eosin Y( EY), an anionic dye, as these molecules may be used as model pollutants.…”

“…This molecule belongs to a group of foldamers containing the 4‐carboxy‐5‐methyl‐oxazolidin‐2‐one unit (Oxd) or the p ‐glutamic acid unit (pGlu) . These molecules cause a local constraint in the pseudopeptide chain that favours the formation of secondary structures, fibers and gels . Thus we prepared hydrogels based on Fmoc‐ l ‐Phe‐ d ‐pGlu‐OH to test them for the adsorption of Methylene Blue (MB), a cationic dye, and Eosin Y (EY), an anionic dye, as these molecules may be used as model pollutants.…”

Expanding the Functional Scope of the Fmoc‐Diphenylalanine Hydrogelator by Introducing a Rigidifying and Chemically Active Urea Backbone Modification

“…This molecular design has led to metabolically stable nanostructures with tuneable mechanical properties, which serve as platforms in therapeutic and biomedical applications . Such studied peptidomimetic hydrogelators include depsipeptides, oxazolidine‐tethered, and cyclobutane‐tethered peptides, which form hydrogels of improved rigidity and longer biostability compared to their native α‐peptide counterparts. Here, we aimed to further explore the beneficial effect of backbone modification on hydrogel properties and functionalities.…”

Ultrashort Peptide Self-Assembly: Front-Runners to Transport Drug and Gene Cargos

“…This asserted the overall impact of Fmoc and Boc groups. Efficient loading and release capabilities along with enhanced toxicity against cancer cells emphasize the role of self-assembly of a simple amino acid as a drug carrier (Tao et al, 2015;Zanna et al, 2015;Dube et al, 2017).…”