Peptide-based drugs, despite being relegated as niche pharmaceuticals for years, are now capturing more and more attention from the scientific community. The main problem for these kinds of pharmacological compounds was the low degree of cellular uptake, which relegates the application of peptide-drugs to extracellular targets. In recent years, many new techniques have been developed in order to bypass the intrinsic problem of this kind of pharmaceuticals. One of these features is the use of stapled peptides. Stapled peptides consist of peptide chains that bring an external brace that force the peptide structure into an $\alpha$ -helical one. The cross-link is obtained by the linkage of the side chains of opportune-modified amino acids posed at the right distance inside the peptide chain. In this account, we report the main stapling methodologies currently employed or under development and the synthetic pathways involved in the amino acid modifications. Moreover, we report the results of two comparative studies upon different kinds of stapled-peptides, evaluating the properties given from each typology of staple to the target peptide and discussing the best choices for the use of this feature in peptide-drug synthesis.

The rational design of heterojunctions based on metal halide perovskites (MHPs) is an effective route to create novel photocatalysts to run relevant solar‐driven reactions. In this work, an experimental and computational study on the synergic coupling between a lead‐free Cs₃Bi₂Br₉ perovskite derivative and g‐C₃N₄ is presented. A relevant boost of the hydrogen photogeneration by more than one order of magnitude is recorded when going from pure g‐C₃N₄ to the Cs₃Bi₂Br₉/g‐C₃N₄ system. Effective catalytic activity is also achieved in the degradation of the organic pollutant with methylene blue as a model molecule. Based upon complementary experimental outputs and advanced computational modeling, a rationale is provided to understand the heterojunction functionality as well as the trend of hydrogen production as a function of perovskite loading. This work adds further solid evidence for the possible application of MHPs in photocatalysis, which is emerging as an extremely appealing and promising field of application of these superior semiconductors.

In this paper we provide an accurate high-pressure structural and optical study of the MAPbI3 hybrid perovskite. Structural data show the presence of a phase transition toward an orthorhombic structure around 0.3 GPa followed by full amorphization of the system above 3 GPa. After releasing the pressure, the system keeps the high-pressure orthorhombic phase. The occurrence of these structural transitions is further confirmed by pressure induced variations of the photoluminescence signal at high pressure. These variations clearly indicate that the bandgap value and the electronic structure of MAPI change across the phase transition.