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A double-walled tetrahedral metal-organic cage assembled in solution from silver(I), 2-formyl-1,8-naphthyridine, halide, and a threefold-symmetric triamine. The AgI 4 X clusters at its vertices each bring together six naphthyridine-imine moieties, leading to a structure in which eight tritopic ligands bridge four clusters in an (AgI 4 X)4 L8 arrangement. Four ligands form an inner set of tetrahedron walls that are surrounded by the outer four. The cage has significant interior volume, and was observed to bind anionic guests. The structure also possesses external binding clefts, located at the edges of the cage, which bound small aromatic guests. Halide ions bound to the silver clusters were observed to exchange in a well-defined hierarchy, allowing modulation of the cavity volume. The principles uncovered here may allow for increasingly more sophisticated cages with silver-cluster vertex architectures, with post-assembly tuning of the interior cavity volume enabling targeted binding behavior.

Peptide assembly is attractive not only to develop biotechnological tools and smart nanomaterials, but also to treat pathologies in new ways. This Review focuses on recent progress made in the exciting area pertaining the interaction between peptide assemblies and proteins. Earlier works aimed to identify proteins able to bind peptide assemblies for therapeutics' delivery and biocompatible scaffolds. Recent advancements cover more applications that go beyond tissue regeneration and biomaterials. On one hand, self-assembling peptides interacting with proteins can inhibit pathological amyloid fibrillation, or boost the immune response to vaccines. On the other, they have been exploited to promote protein crystallization, also for therapeutics' delivery. As research advances in this exciting area, it opens the way towards a qualitative leap in the clinical translation of supramolecular medicinal chemistry to creatively tackle unmet challenges of modern disease treatment and prevention.

N-(4-Nitrobenzoyl)-Phe self-assembled into a transparent supramolecular hydrogel, which displayed high fibroblast and keratinocyte cell viability. The compound showed a mild antimicrobial activity against E. coli both as a hydrogel and in solution. Single-crystal XRD data revealed packing details, including protonation of the C-terminus due to an apparent pK(a) shift, as confirmed by pH titrations. MicroRaman analysis revealed almost identical features between the gel and crystal states, although more disorder in the former. The hydrogel is thermoreversible and disassembles within a range of temperatures that can be fine-tuned by experimental conditions, such as gelator concentration. At the minimum gelling concentration of 0.63 wt %, the hydrogel disassembles in a physiological temperature range of 39-42 degrees C, thus opening the way to its potential use as a biomaterial.

Unprotected dipeptides are attractive building blocks for environmentally friendly hydrogel biomaterials by virtue of their low-cost and ease of preparation. This work investigates the self-assembling behaviour of the distinct stereoisomers of Ile-Phe and Phe-Ile in phosphate buffered saline (PBS) to form hydrogels, using transmission electron microscopy (TEM), attenuated total reflectance infrared spectroscopy (ATR-IR), circular dichroism (CD), and oscillatory rheometry. Each peptide purity and identity was also confirmed by 1 H- and 13 C-NMR spectroscopy and HPLC-MS. Finally, single-crystal XRD data allowed the key interactions responsible for the supramolecular packing into amphipathic layers or water-channels to be revealed. The presence of the latter in the crystal structure is a distinctive feature of the only gelator of this work that self-organizes into stable hydrogels, with fast kinetics and the highest elastic modulus amongst its structural isomers and stereoisomers.

Self-assembling short peptides have attracted great interest as enzyme mimics, especially if the catalytic activity resides solely in the supramolecular structure so that it can be switched on/off as needed by controlling assembly/disassembly. Among the various enzyme classes, hydrolases find wide application in biomaterials, and their mimetics often contain His residues, in addition to either divalent cations or other amino acids to mimic the catalytic site. This work reports two self-assembling tetrapeptides based on the Ser-His motif for catalysis and the Phe-Phe motif to drive amyloid structure formation. Both peptides form thermoreversible hydrogels in phosphate buffer at neutral pH that display a mild esterase-like activity, as demonstrated on the hydrolysis of 4-nitrophenyl acetate as a model substrate, although presence of Ser did not enhance catalytic activity. The systems are characterised by circular dichroism, transmission electron microscopy, oscillatory rheology and Thioflavin T fluorescence as an amyloid stain, to provide further insights that may assist the future design of improved supramolecular catalysts.

Die Nutzung von auf festen Substraten gezogenem oder abgeschiedenem Graphen bietet wesentliche Vorteile, wenn man mithilfe von Funktionalisierungsprozessen fein abgestimmte Strukturen für die Elektronik und “intelligente” Materialien erzielen möchte. In diesem Aufsatz konzentrieren wir uns zunächst auf die Natur und die Eigenschaften von Graphen auf Substraten in Abhängigkeit von den jeweiligen Herstellungsverfahren. Anschließend analysieren wir die maßgebliche Literatur zur Funktionalisierung von Graphen auf einem Substrat. Insbesondere werden wir radikalische Reaktionen, Cycloadditionen, Halogenierungen, Hydrierungen und Oxidationen vergleichend diskutieren. Dabei werden wir besonders auf die Frage eingehen, wie die Reaktivität von Graphen durch seine Morphologie beeinflusst wird (d. h. Anzahl von Lagen, Defekte, Substrat, Krümmung usw.).

Carbon nanotubes have emerged as unique carbon allotropes that bear very interesting prospects in catalysis. Their use is mostly related to that of supports for inorganic metal catalysts, including molecular catalysts, metal nanoparticles, metal oxides or even more complex hierarchical hybrids. However, several reports have shown that they can intriguingly act as metal-free catalysts, with performance often superior to that of other carbon materials, in particular when ad hoc organic functional groups are attached prior to catalytic screening. The range of catalytic reactions is quite wide, and it includes standard organic synthesis, electrocatalysis, photocatalysis as well as other important industrial processes. In the last few years, the energy sector has acquired a dominant role as one of the most sought-after fields of application, given its ever-increasing importance in society.

The combination of the very different chemical natures of carbon nanotubes (CNTs) and proteins gives rise to systems with unprecedented performance, thanks to a rich pool of very diverse chemical, electronic, catalytic and biological properties. Here we review recent advances in the field, including innovative and imaginative aspects from a nanoscale point of view. The tubular nature of CNTs allows for internal protein encapsulation, and also for their external coating by protein cages, affording bottom-up ordering of molecules in hierarchical structures. To achieve such complex systems it is imperative to master the intermolecular forces between CNTs and proteins, including geometry effects (e.g. CNT diameter and curvature) and how they translate into changes in the local environment (e.g. water entropy). The type of interaction between proteins and CNTs has important consequences for the preservation of their structure and, in turn, function. This key aspect cannot be neglected during the design of their conjugation, be it covalent, non-covalent, or based on a combination of both methods. The review concludes with a brief discussion of the very many applications intended for CNT–protein systems that go across various fields of science, from industrial biocatalysis to nanomedicine, from innovative materials to biotechnological tools in molecular biology research.