Peptide-based Supramolecular Colloids

Peptide-based supramolecular colloids are assembled systems based on weak interactions between peptides (such as hydrogen bonding, electrostatic forces, hydrophobic effects, pi-pi interactions, and van der Waals forces), spontaneously formed in a bottom-up manner. Peptide-based supramolecular colloids have ordered molecular arrangements and regular structures, with characteristics of both traditional colloids and supramolecular systems. Constructing functional supramolecular colloids via weak intermolecular interactions assists in understanding the process of biomolecular self-assembly in vivo and provides an effective strategy for designing supramolecular materials with excellent performance. Peptides, consisting of several amino acids, are elegant building blocks in supramolecular chemistry as well as colloid and interface chemistry because of their biological origin, clear composition, low immunogenicity, structural programmability, excellent biosafety, and high biodegradability. Based on the approach of supramolecular self-assembly, peptides can be manipulated to form multiscale and multifunctional colloidal systems, which have widespread applications in medicine, catalysis, energy, nanotechnology, and other fields. However, the realization of precise control of the structures and functions of these supramolecular colloids through peptide design and intermolecular interactions regulation remains an important issue to be addressed. To study the assembly process and physicochemical mechanism of supramolecular colloids at the molecular scale, and to explore the relationship between colloidal structure and function, the construction and functionalization of supramolecular colloids must be achieved. This work is a systematic summary of the assembly mechanism, structures, and functions as well as the state of the art of peptide-based supramolecular colloids with emphasis on the regulation of intermolecular interactions and structure-function relationships. The research progress of peptide-based supramolecular colloids in the following fields is summarized herein: i) biomimetic photosynthesis, including light capture and charge separation; and ii) tumor phototherapies, including photothermal therapy (PTT) and photodynamic therapy (PDT). Currently, it is feasible to induce functional enhancement of peptide colloids via supramolecular assembly. The most important aspect is to design the primary structure of the peptide building block, to precisely control the weak interactions between peptide molecules and rationally optimize the self-assembly process, and control the size and structure of the assemblies. Followup studies should focus on the design of molecular precursors, the combination of basic research and practical application of peptide-based supramolecular colloids will be essential. The advantages of peptide-based supramolecular colloids, including their ordered organization, flexible structures, and versatile functions, will open up novel avenues for various applications of supramolecular colloids in fields such as green energy and medicine. It is hoped that this review will provide inspiration and broaden ideas to further drive the development and application of supramolecular colloids.