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G-Quadruplexes (G4s) are appealing targets for anticancer therapy because of their location in the genome and their role in regulating physiological and pathological processes. In this article, we report the characterization of the molecular interaction and selectivity of OAF89, a 9,10-disubstituted G4-binding anthracene derivative, with different DNA sequences. Advanced analytical methods, including mass spectrometry and nuclear magnetic resonance, were used to conduct the investigation, together with the use of in silico docking and molecular dynamics. Eventually, the compound was tested in vitro to assess its bioactivity against lung cancer cell lines.

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The characterization of the structure of ferritin in solution and the arrangement of iron stored in its cavity are intriguing subjects for both cell biology and applied science, since the protein structure, stability, and easiness of production make it an ideal tool for biomedical applications. We characterized the ferritin structure over a wide range of iron loadings by visible light, X-ray, and neutron scattering techniques. We found that the arrangement of iron ions inside the protein cage resulted in a more disposable arrangement at lower loading factors and then in a crystalline structure. At very high iron content the inner core is composed of magnetite more than ferrihydrite, and the shell of the protein is elastically deformed by the iron crystal growth in an ellipsoidal arrangement. The application of an external radiofrequency (RF) magnetic field affected ferritins at low iron loading factors. Notably the RF modified the iron disposition towards a more dispersed arrangement. The structural characterization of the ferritin at different LFs and in presence of magnetic fields provides useful insights into their physiological behaviour and can help in the design and fine-tuning of ferritin-based nanosystems for biotechnological applications.

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In the central nervous system, some specific phosphodiesterase (PDE) isoforms modulate pathways involved in neuronal plasticity. Accumulating evidence suggests that PDE9 may be a promising therapeutic target for neurodegenerative diseases. In the current study, computational techniques were used to identify a nature-inspired PDE9 inhibitor bearing the scaffold of an isoflavone, starting from a database of synthetic small molecules using a ligand-based approach. Furthermore, docking studies supported by molecular dynamics investigations allowed us to evaluate the features of the ligand-target complex. In vitro assays confirmed the computational results, showing that the selected compound inhibits the enzyme in the nanomolar range. Additionally, we evaluated the expression of gene and protein levels of PDE9 in organotypic hippocampal slices, observing an increase following exposure to kainate (KA). Importantly, the PDE9 inhibitor reduced CA3 damage induced by KA in a dose-dependent manner in organotypic hippocampal slices. Taken together, these observations strongly support the potential of the identified nature-inspired PDE9 inhibitor and suggest that such a molecule could represent a promising lead compound to develop novel therapeutic tools against neurological diseases..

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The growing interest on the therapeutic potential against neurodegeneration of Cannabis sativa extracts, and of phytocannabinoids in particular, is paralleled by a limited understanding of the undergoing biochemical pathways in which these natural compounds may be involved. Computational tools are nowadays commonly enrolled in the drug discovery workflow and can guide the investigation of macromolecular targets for such molecules. In this contribution, in silico techniques have been applied to the study of C. sativa constituents at various extents, and a total of seven phytocannabinoids and four terpenes were considered. On the side of ligand-based virtual screening, physico-chemical descriptors were computed and evaluated, highlighting the phytocannabinoids possessing suitable drug-like properties to potentially target the central nervous system. Our previous findings and literature data prompted us to investigate the interaction of these molecules with phosphodiesterases (PDEs), a family of enzymes being studied for the development of therapeutic agents against neurodegeneration. Among the compounds, structure-based techniques such as docking and molecular dynamics (MD), highlighted cannabidiol (CBD) as a potential and selective PDE9 ligand, since a promising calculated binding energy value (-9.1 kcal/mol) and a stable interaction in the MD simulation timeframe were predicted. Additionally, PDE9 inhibition assay confirmed the computational results, and showed that CBD inhibits the enzyme in the nanomolar range in vitro, paving the way for further development of this phytocannabinoid as a therapeutic option against neurodegeneration.

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The cytotoxicity of ionic liquids (ILs) has been receiving attention in the context of the biological and environmental impact of their vast field of applications. It has been ascertained that the cell membrane is the main target of ILs when they interact with microorganisms, cells and bacteria; nevertheless, studies at the micro- and nano-scale aiming at better understanding of the fundamental mechanisms of toxicity of ILs are lacking. In this work, we used atomic force microscopy (AFM) to investigate the impact of room-temperature ILs on the mechanical, morphological and electrostatic properties of solid-supported DOPC phospholipid bilayers, taken as models of biomembranes. In particular, we have characterized the concentration-dependent and time-dependent evolution of the morphological, structural and mechanical properties of DOPC lipid membranes in the presence of imidazolium-based ILs with different alkyl chain lengths and hydrophilic/hydrophobic characteristics. The majority of ILs investigated were found to possess the ability of restructuring the lipid bilayer, through the formation of new IL/lipid complexes, showing distinctive morphological features (increase of area and roughness). The nanomechanical analysis of the lipid membrane exposed to ILs revealed a progressive, concentration-dependent perturbation of the structural ordering and rigidity of the membrane, evidenced by a decrease in the breakthrough force, Young's modulus and area stretching modulus. AFM detected a modification of the electrostatic double-layer at the membrane surface, in terms of a reduction of the original negative surface charge density, suggesting a progressive stratification of cations on the exposed leaflet of the lipid membrane. Our findings may be helpful in designing novel ILs with tailored interaction with biological membranes.

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Two sets of unprecedented push-pull isoquinolines, characterized by an opposite "dipolar moment" with respect to the longitudinal axis of the molecule, have been prepared. The key step of the approach is the microwave-promoted domino imination/cycloisomerization of 2-alkynyl benzaldehydes in the presence of methanolic ammonia. Absorption spectra and emission spectra of the D-π-A isoquinolines and their alkynyl precursors in nine different solvents have been recorded. The absolute QYs of all compounds have been recorded in three solvents with different polarities, i.e. toluene, DMSO and ethanol. Among the D-π-A isoquinolines prepared - nicknamed QuinaChroms - two compounds characterized by opposite dipolar moments, i.e. 3-(4-methoxyphenyl)-7-nitroisoquinoline 1a and N,N-diethyl-3-(4-(methylsulfonyl)phenyl)isoquinolin-7-amine 2b displayed more interesting photophysical profiles, whereas 5-(diethylamino)-2-(A)arylethynylbenzaldehydes precursors 8a-c - having a free aldehyde group that is suitable for possible conjugation - exhibited strong fluorescence and wide Stokes shifts. These products are interesting for potential use as polarity-sensitive fluorescent probes or advanced functional materials.