The three tripeptides Dff, Hff, and hFF were synthesised by solid phase with a standard Fmoc protection strategy, Oxyma Pure B as coupling agent, and a Rink amide linker on 2-chlorotrityl chloride resin. They were purified by reversed-phase HPLC, and their purity and identity were confirmed by 1H-and 13C-NMR and ESI-MS (see ESI). Then, self-assembly and hydrogelation were probed by a pH trigger, which consisted of dissolving the peptides in alkaline phosphate buffer, followed by dilution with an equal volume of mildly acidic phosphate buffer to reach a neutral pH 7.0 ± 0.1. In this way, each peptide formed hydrogels at 10 mM, however, we characterised the systems at 25 mM to enable comparison with the literature.20