Fmoc-FF and hexapeptides-based multicomponent hydrogels as scaffold materials

Short peptides or single amino acids are interesting building blocks for hydrogels fabrication, frequently used as extracellular matrix-mimicking scaffolds for cell growth in tissue engineering. The combination of two or more peptide hydrogelators could allow the obtaining of different materials exhibiting new architectures, tunable mechanical properties, high stability and improved biofunctionality. Here we report on the synthesis, formulation and multi-scale characterization of peptidebased mixed hydrogels formed by the low molecular weight Fmoc-FF (N?-fluorenylmethyloxycarbonyl diphenylalanine) hydrogelator and of the PEG8-(FY)3 hexapeptide, containing three repetitions of Phe-Tyr motif and a PEG moiety at its Nterminus. Mixed hydrogels were also prepared replacing PEG8-(FY)3 with its analogue (FY)3, without the PEG moiety. Rheology analysis confirmed the improved mechanical features of the multicomponent gels prepared at two different ratios (2/1 or 1/1, v/v). However, the presence of the hydrophilic PEG polymeric moiety causes a slowing down of the gel kinetic formation (from 42 to 18 minutes) and a decrease of the gel rigidity (G' from 9 to 6 kPa). Preliminary in vitro biocompatibility and cell adhesion assays performed on Chinese Hamster Ovarian (CHO) suggest a potential employ of these multicomponent hydrogels as exogenous scaffold materials for tissue engineering.