The uncapped tripeptide DPhe-Phe-Leu acts as self-assembly template to yield supramolecular hydrogel biomaterials. As an example, self-assembling DPhe-Phe-Leu-Asp-Val contains the LDV bioadhesive motif for β1 integrin activation. Hydrogels made of the two peptides successfully mimic fibronectin of the extracellular matrix and lead to high cell viability, adhesion, and spreading.
The family of carbon nanostructures comprises several members, such as fullerenes, nano-onions, nanodots, nanodiamonds, nanohorns, nanotubes, and graphene-based materials. Their unique electronic properties have attracted great interest for their highly innovative potential in nanomedicine. However, their hydrophobic nature often requires organic solvents for their dispersibility and processing. In this review, we describe the green approaches that have been developed to produce and functionalize carbon nanomaterials for biomedical applications, with a special focus on the very latest reports.
The use of peptides to template inorganic nanoparticle formation has attracted great interest as a green route to advance structures with innovative physicochemical properties for a variety of applications that range from biomedicine and sensing, to catalysis. In particular, short-peptide gelators offer the advantage of providing dynamic supramolecular environments for the templating effect on the formation of inorganic nanoparticles directly in the resulting gels, and ideally without using further reductants or chemical reagents. This mini-review describes the recent progress in the field to outline future research directions towards dynamic functional materials that exploit the synergy between supramolecular chemistry, nanoscience, and the interface between organic and inorganic components for advanced performance.
Self-assembling peptides are attracting wide interest as biodegradable building blocks to achieve functional nanomaterials that do not persist in the environment. Amongst the many applications, biocatalysis is gaining momentum, although a clear structure-to-activity relationship is still lacking. This work applied emerging design rules to the heterochiral octapeptide sequence His–Leu–DLeu–Ile–His–Leu–DLeu–Ile for self-assembly into nanofibrils that, at higher concentration, give rise to a supramolecular hydrogel for the mimicry of esterase-like activity. The peptide was synthesized by solid-phase and purified by HPLC, while its identity was confirmed by 1H-NMR and electrospray ionization (ESI)-MS. The hydrogel formed by this peptide was studied with oscillatory rheometry, and the supramolecular behavior of the peptide was investigated with transmission electron microscopy (TEM) analysis, circular dichroism (CD) spectroscopy, thioflavin T amyloid fluorescence assay, and attenuated total reflectance (ATR) Fourier-transform infrared (FT-IR) spectroscopy. The biocatalytic activity was studied by monitoring the hydrolysis of p-nitrophenyl acetate (pNPA) at neutral pH, and the reaction kinetics followed an apparent Michaelis–Menten model, for which a Lineweaver–Burk plot was produced to determine its enzymatic parameters for a comparison with the literature. Finally, LC–MS analysis was conducted on a series of experiments to evaluate the extent of, if any, undesired peptide acetylation at the N-terminus. In conclusion, we provide new insights that allow gaining a clearer picture of self-assembling peptide design rules for biocatalysis.
Cysteine redox chemistry is widely used in nature to direct protein assembly, and in recent years it has inspired chemists to design self-assembling peptides too. In this concise review, we describe the progress in the field focusing on the recent advancements that make use of Cys thiol–disulfide redox chemistry to modulate hydrogelation of various peptide classes.
Nanostructured titania (TiO2) is the most widely applied semiconducting oxide for a variety of purposes, and it is found in many commercial products. The vast majority of uses rely on its photo-activity, which, upon light irradiation, results in excited states that can be used for diverse applications. These range from catalysis, especially for energy or environmental remediation, to medicine—in particular, to attain antimicrobial surfaces and coatings for titanium implants. Clearly, the properties of titania are enhanced when working at the nanoscale, thanks to the increasingly active surface area. Nanomorphology plays a key role in the determination of the materials’ final properties. In particular, the nucleation and growth of nanosized titania onto carbon nanostructures as a support is a hot topic of investigation, as the nanocarbons not only provide structural stability but also display the ability of electronic communication with the titania, leading to enhanced photoelectronic properties of the final materials. In this concise review, we present the latest progress pertinent to the use of nanocarbons as templates to tailor nanostructured titania, and we briefly review the most promising applications and future trends of this field.