Noncovalent interactions are the main driving force in the folding of proteins into a 3D functional structure. Motivated by the wish to reveal the mechanisms of the associated self-assembly processes, scientists are focusing on studying self-assembly processes of short protein segments (peptides). While this research has led to major advances in the understanding of biological and pathological process, only in recent years has the applicative potential of the resulting self-assembled peptide assemblies started to be explored. Here, major advances in the development of biomimetic supramolecular peptide assemblies as coatings, gels, and as electroactive materials, are highlighted. The guiding lines for the design of helical peptides, β strand peptides, as well as surface binding monolayer-forming peptides that can be utilized for a specific function are highlighted. Examples of their applications in diverse immerging applications in, e.g., ecology, biomedicine, and electronics, are described. Taking into account that, in addition to extraordinary design flexibility, these materials are naturally biocompatible and ecologically friendly, and their production is cost effective, the emergence of devices incorporating these biomimetic materials in the market is envisioned in the near future.

This paper describes the formation of complex peptide-based structures by the coassembly of two simple peptides, the diphenylalanine peptide and its tert-butyl dicarbonate (Boc) protected analogue. Each of these peptides can self-assemble into a distinct architecture: the diphenylalanine peptide into tubular structures and its analogue into spheres. Integrated together, these peptides coassemble into a construction of beaded strings, where spherical assemblies are connected by elongated elements. Electron and scanning force microscopy demonstrated the morphology of these structures, which we termed "biomolecular necklaces". Additional experiments indicated the reversibility of the coassembly process and the stability of the structures. Furthermore, we suggest a possible mechanism of formation for the biomolecular necklaces. Our suggestion is based on the necklace model for polyelectrolyte chains, which proposes that a necklace structure appears as a result of counterion condensation on the backbone of a polyelectrolyte. Overall, the approach of coassembly, demonstrated using aromatic peptides, can be adapted to any peptides and may lead to the development and discovery of new self-assembled architectures formed by peptides and other biomolecules.

The synthesis and the structural characterization of dipeptides composed of unnatural fluorine-substituted β(2,3)-diarylamino acid and L-alanine are reported. Depending on the stereochemistry of the β amino acid, these dipeptides are able to self-assemble into proteolytic stable nanotubes. These architectures were able to enter the cell and locate in the cytoplasmic/perinuclear region and represent interesting candidates for biomedical applications.

Due to extension of life expectancy, millions of people suffer nowadays from bone and dental malfunctions that can only be treated by different types of implants. However, these implants tend to fail due to bacterial infection and lack of integration with the remaining tissue. Here, we demonstrate a new concept in which we use specifically designed peptides, in a “Lego-like” manner to endow multiple preprogrammed functions. We developed a bifunctional peptide-based coating that simultaneously rejects the adhesion of infecting bacteria and attracts cells that build the new connecting tissue. The peptide design contains fluorinated phenylalanine that mediates the self-assembly of the peptide into a coating that resists bacterial adhesion. It also includes an Arg-Gly-Asp (RGD) motif that attracts mammalian cells. The whole compound is attached to the surface using a third unit, the amino acid 3,4-dihydroxyphenylalanine (DOPA). This novel, yet very simple approach is significantly advantageous for practical use and synthesis. More importantly, this peptide design can serve as a general platform for generating functional coatings.

This communication describes the co-assembly of polydopamine spheres, either bare or coated with Fe3O4 magnetic nanoparticles, with the short aromatic peptide diphenylalanine. The combination of polydopamine particles and diphenylalanine generated tubular structures decorated with adhesive spherical particles, while the co-assembly of the polydopamine spheres coated with magnetic Fe3O4 nanoparticles with diphenylalanine resulted in the formation of a magnetic hydrogel. These new architectures may be useful as new vehicles for several applications including tissue regeneration and drug delivery.

Bioinspired smart materials represent a tremendously growing research field and the obtainment of new building blocks is at the molecular basis of this technology progress. In this work, colloidal materials have been prepared in few steps starting from ribonucleosides. Nucleobase morpholino β-amino acids are the chimera key intermediates allowing Phe–Phe dipeptides’ functionalization with adenine and thymine. The obtained compounds self-aggregate showing enhanced photoluminescent features, such as deep blue fluorescence and phosphorescence emissions.

ObjectivesThe aim of this study was to investigate whether a peptide‐based coating can prevent the adhesion of Porphyromonas gingivalis, a key human pathogen associated with periodontitis and peri‐implantitis.BackgroundNonsurgical and surgical interventions have been used for the treatment of peri‐implantitis; however, the effectiveness of these approaches is usually unsatisfactory. The main reason is that dental plaque on the surface of the implant is difficult to remove due to its rough surface and thread design. Recently, a peptide‐based coating for implant surfaces that can reject the adhesion of Escherichia coli and improve the attachment of host cells was developed.MethodsA salivary pellicle was created on the surfaces of peptide‐coated bare discs and verified with anti‐human immunoglobulin G, A and M, and anti‐fibrinogen. Early colonizers, Veillonella parvula and Streptococcus sobrinus, and the later colonizer, Porphyromonas gingivalis, were labelled with green and red fluorescent dyes, respectively, and seeded on the discs. Bacterial attachment was semi‐quantified by fluorescence intensity.ResultsThe salivary pellicle was evenly distributed on the discs, with or without the peptide coating, with an average thickness of 3.84 µm. A multi‐species dental biofilm was created on the salivary pellicle. The peptide coating resulted in an approximate 25% reduction in the attachment of Veillonella parvula and Streptococcus sobrinus, and a 50% reduction in Porphyromonas gingivalis, when compared to control, uncoated implant discs.ConclusionThe novel peptide‐based coating can inhibit the attachment of Porphyromonas gingivalis. It may have the potential to impede the development of peri‐implantitis.

Polyelectrolyte multilayers (PEMs) assembled layer-by-layer have emerged as functional polymer films that are both stable and capable of containing drug molecules for controlled release applications. Most of these applications concentrate on sustained release, where the concentration of the released molecules remains rather constant with time. However, high-efficiency delivery requires obtaining high local concentrations at the vicinity of the cells, which is achieved by triggered release. Here, we show that a nanopatterned PEM platform demonstrates superior properties with respect to drug retention and triggered delivery. A chemically modified block copolymer film was used as a template for the selective deposition of poly­(ethylene imine) and a charged derivative of the electroactive poly­(3,4-ethylenedioxythiophene) together with a drug molecule. This nanopatterned PEM shows the following advantages: (1) high drug loading; (2) enhanced retention of the bioactive molecule; (3) release triggered by an electrochemical stimulus; (4) high efficacy of drug delivery to cells adsorbed on the surface compared to the delivery efficacy of a similar concentration of drug to cells suspended in a solution.