Novel self-assembling peptide hydrogel with pH-tunable assembly microstructure, gel mechanics and the entrapment of curcumin

Insight is provided into the mechanism of peptide gelation, a self-assembled process of particular interest, due to its wide existence in natural events and broad applications in food and biomaterials field, but hard to control as minor alterations in the peptide sequence. Here, we design a family of pentapeptides and control their self-assembly behaviors, from micro- and nanoparticles to nanofibers and hydrogels. Furthermore, based on the thermodynamics, the gelation kinetics and the ionization status of terminal groups, the peptide assembly goes through five stages as varying the pH value and the assembly structures are highly dependent on the charging status of the terminal groups. The gelation rules of these peptides are further investigated. Besides, we also load hydrophobic functional molecule (curcumin) into different self-assembly nanostructures with high encapsulation efficiency and remarkable thermal and light protection on curcumin. These peptides assemblies with tunable structures, encapsulation ability and photothermal stabilization could become promising candidates for hydrophobic function factor delivery in food industry.