Multicomponent Peptide-Based Hydrogels Containing Chemical Functional Groups as Innovative Platforms for Biotechnological Applications

Abstract

Multicomponent hydrogels (HGs) based on ultrashort aromatic peptides have been exploited as biocompatible matrices for tissue engineering applications, the delivery of therapeutic and diagnostic agents, and the development of biosensors. Due to its capability to gel under physiological conditions of pH and ionic strength, the low molecular-weight Fmoc-FF (Nα-fluorenylmethoxycarbonyl-diphenylalanine) homodimer is one of the most studied hydrogelators. The introduction into the Fmoc-FF hydrogel of additional molecules like protein, organic compounds, or other peptide sequences often allows the generation of novel hydrogels with improved mechanical and functional properties. In this perspective, here we studied a library of novel multicomponent Fmoc-FF based hydrogels doped with different amounts of the tripeptide Fmoc-FFX (in which X= Cys, Ser, or Thr). The insertion of these tripeptides allows to obtain hydrogels functionalized with thiol or alcohol groups that can be used for their chemical post-derivatization with bioactive molecules of interest like diagnostic or biosensing agents. These novel multicomponent hydrogels share a similar peptide organization in their supramolecular matrix. The hydrogels’ biocompatibility, and their propensity to support adhesion, proliferation, and even cell differentiation, assessed in vitro on fibroblast cell lines, allows us to conclude that the hybrid hydrogels are not toxic and can potentially act as a scaffold and support for cell culture growth.

Ultrashort Cationic Peptide Fmoc-FFK as Hydrogel Building Block for Potential Biomedical Applications

“…According to Equation (1), the q values are calculated by putting the gel in contact with water and determining the increase in weight that occurs. The swelling percentage ranged between 32 and 37% for all the samples (Table 1) and resulted to be slightly higher than the percentage determined for the pure Fmoc-FF hydrogel (29%) [36,37]. This value is in agreement with the ones observed for similar Fmoc-FF/tripeptide mixed systems.…”

“…The relatively low swelling percentage may be due to the high hydrophobic component of the sequence, as a substantial aromatic part is present and may contribute to the low amount of entrapped water. Indeed, the addition of a more hydrophilic component results in an increase in the swelling ratio when compared to that of the pure Fmoc-FF (see Table S1) [36].…”