Amino Acids Modification to Improve and Fine-Tune Peptide- Based Hydrogels

Abstract

Among all the materials used in industry, gels play an increasingly important role. These so-called soft-matter materials are defined by their ability to fix a large amount of sol-vent, either organic (organogels) or aqueous (hydrogels). The large majority of hydrogels are made of natural or synthetic polymers, or natural proteins. However, a new kind of hydrogel has appeared: the peptide-based hydrogels, developed from short amino acids sequences (<20 amino acids). Due to their exceptional qualities in term of biocompat-ibility, biodegradability, and atom economy, these peptide-based hydrogels open new horizons in term of applications. They are mainly considered in the biomedical domain as injectable hydrogels, or as an extracellular culture matrix to support cell culture. While important, the possibilities of peptide design can exponentially grow using modified and non-natural amino acids instead of the " only " twenty natural ones. Thus, chemical modi-fications virtually offer infinite opportunities both to improve applications window and to fine-tune properties of the resulting hydrogels. In this context, this chapter proposes to review peptide and amino acid modifications reported to impact the resulting hydrogel.