Sessile organisms have undergone long‐term evolution to develop the unique ability by positioning themselves on wet solid surface through secreting adhesive proteins. The present study reveals that natural amino acid monomers can also exhibit similar adhesion capacity. This kind of biomimetic adhesives were created by the one‐step aqueous assembly of basic amino acids with assistance of anionic polyoxometalates. The polyoxometalates not only serve as multivalent scaffold to initiate the supramolecular cross‐linking of amino acid molecules, but also function as a redox component, bestowing the wet adhesives with electrochromic features.

innovative insight into understanding the properties of the material systems beyond molecular level. [6-8] Through the last decades, supramolecular chemistry has deeply permeated and fused with biology and materials science, and has gradually growth into an interdisciplinary platform for the creation of self-assembled systems with extraordinary properties. [9-12] Among the numerous systems, self-assembled peptide is one of the most important branches, because of its rich chemical diversity, versatile characters, inherent biocompatibility, and bioactivity. [13-15] Specifically, the natural or chemically engineered amino acids encoded in the sequence of peptide molecules enable the formation of customizable secondary structures, the cooperative interactions between main chains and side chains of peptide molecules can be further leveraged to produce hierarchical nanostructures [16-22] and important biofunctions, such as drug delivery, [23-25] tissue engineering, [26-28] regenerative medicine, [29-31] and biomineralization. [32-35] Moreover, many studies have disclosed that self-assembled peptide nanostructures can offer higher performance (catalytic, therapeutic, targeting, etc.) than peptide itself. [36-42] For those reasons, peptide self-assembly has been recognized as a subject of great importance in supramolecular chemistry, biology, and nanotechnology, and the breadth and depth of peptide selfassemblies have been documented and demonstrated in several excellent reviews. [43-51] Besides the self-assembly of unimolecular peptides, multicomponent coassembly between peptides and other building blocks has recently become increasingly prevalent, as the modular approach offers a simple and effective way to arrive at supramolecular materials with wide structural complexity and value-added properties for multiple tasks applications. [52-56] This integrated characteristic further stimulates researchers to explore the scope of peptide coassembly with the aim of expanding the space of functional utility. To selectively form the multicomponent nanostructures, the interplay of the driving forces should be energetically much more favorable for strengthening the coassembly of distinct components than the self-sorting of the same type of components. [57-59] Following this design criteria, the introduction of complementary noncovalent interactions into the multicomponent systems is Peptide assembly has been extensively exploited as a promising platform for the creation of hierarchical nanostructures and tailor-made bioactive materials. Ionic coassembly of cationic peptides and anionic species is paving the way to provide particularly important contribution to this topic. In this review, the recent progress of ionic coassembly soft materials derived from the electrostatic coupling between cationic peptides and anionic species in aqueous solution is systematically summarized. The presentation of this review starts from a brief background on the general importance and advantages of peptide-based ionic coassembly. After that, divers...

Self-assembly has been identified as an innovative strategy for improving the antimicrobial efficacy and bioavailability of short peptides. However, the detailed molecular information of short peptides linking to the self-assembly structures and antimicrobial activity remains to be more clearly understood. This work reported that the constitutional isomeric sequences of cationic peptides showed a significant impact on their antimicrobial activity. We investigated the self-assembly structures of two constitutional isomeric peptides Ac-RFSFSFR-NH2 and Ac-SFRFRFS-NH2, which contained the same serine, alkaline, and phenylalanine residues but in a different order. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) revealed that the constitutional isomers self-assembled into different morphologies in an aqueous solution. The sequence with alkaline residues located at both termini of the peptide favored the formation of β-sheet conformation and nanofibers, while irregular nanospheres were observed when positioning the alkaline residues at the center of the isomeric peptide. The ζ-potential measurements showed that the Ac-RFSFSFR-NH2 nanofibers had a net potential of +17.4 mV, whereas the apparent potential of Ac-SFRFRFS-NH2 nanospheres dropped steeply to +1.0 mV. These differences of the constitutional isomeric peptides were directly reflected in their antimicrobial activities. In comparison with the peptide Ac-SFRFRFS-NH2, the constitutional isomer Ac-RFSFSFR-NH2 exhibited much higher antimicrobial efficacy against Gram-positive Staphylococcus aureus and Bacillus subtilis and Gram-negative Escherichia coli and Pseudomonas aeruginosa. Moreover, several pairs of constitutional isomeric peptides with a similar sequence layout yielded the same outcome. These collective results not only highlight the importance of the isomeric sequence on the antimicrobial efficacy of short peptides but also increase further potential in optimizing the design of self-assembled nano-antimicrobial peptides (AMPs).

The fusion of protein science and peptide science opens up new frontiers in creating innovative biomaterials. Herein, a new kind of adhesive soft materials based on a natural occurring plant protein and short peptides via a simple co‐assembly route are explored. The hydrophobic zein is supercharged by sodium dodecyl sulfate to form a stable protein colloid, which is intended to interact with charge‐complementary short peptides via multivalent ionic and hydrogen bonds, forming adhesive materials at macroscopic level. The adhesion performance of the resulting soft materials can be fine‐manipulated by customizing the peptide sequences. The adhesive materials can resist over 78 cmH2O of bursting pressure, which is high enough to meet the sealing requirements of dural defect. Dural sealing and repairing capability of the protein‐peptide biomaterials are further identified in rat and rabbit models. In vitro and in vivo assays demonstrate that the protein‐peptide adhesive shows excellent anti‐swelling property, low cell cytotoxicity, hemocompatibility, and inflammation response. In particular, the protein‐peptide supramolecular biomaterials can in vivo dissociate and degrade within two weeks, which can well match with the time‐window of the dural repairing. This work underscores the versatility and availability of the supramolecular toolbox in the easy‐to‐implement fabrication of protein‐peptide biomaterials.

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