Black phosphorus/silk fibroin films hamper filamentous and invasive growth of .

The ability of fungi and bacteria to form biofilms on surfaces poses a serious threat to health and a problem in industrial settings. In this work, we investigated how the surface stiffness of silk fibroin (SF) films is modulated by the interaction with black phosphorus (BP) flakes, quantifying the morphogenesis of cells. Raman and infrared (IR) spectroscopies, along with scanning transmission electron microscopy, allowed us to quantify the thickness and diameter of BP flakes dispersed in the SF matrix (, 5.

Assessing Mechanochemical Properties of Acrylonitrile Butadiene Styrene (ABS) Items in Cultural Heritage Through a Multimodal Spectroscopic Approach.

A multimodal spectroscopic approach is proposed to correlate the mechanical and chemical properties of plastic materials in art and design objects, at both surface and subsurface levels, to obtain information about their conservation state and to monitor their degradation. The approach was used to investigate the photo-oxidation of acrylonitrile butadiene styrene (ABS), a plastic commonly found in many artistic and design applications, using ABS-based LEGO bricks as model samples. The modifications of the chemical and viscoelastic properties of ABS during photoaging were monitored by correlative Brillouin and Raman microspectroscopy (BRaMS), combined with portable and noninvasive broad-range external reflection infrared (IR) spectroscopy and nuclear magnetic resonance (NMR) relaxometry, directly applicable in museums.

Hindered intermolecular stacking of anti-parallel telomeric G-quadruplexes.

Telomeric G-quadruplexes (G4s) are non-canonical DNA structures composed of TTAGGG repeats. They are extensively studied both as biomolecules key for genome stability and as promising building blocks and functional elements in synthetic biology and nanotechnology. This is why it is extremely important to understand how the interaction between G4s is affected by their topology.

Conformational transitions in redissolved silk fibroin films and application for printable self-powered multistate resistive memory biomaterials.

3D printing of water stable proteins with elastic properties offers a broad range of applications including self-powered biomedical devices driven by piezoelectric biomaterials. Here, we present a study on water-soluble silk fibroin (SF) films. These films were prepared by mixing degummed silk fibers and calcium chloride (CaCl) in formic acid, resulting in a silk I-like conformation, which was then converted into silk II by redissolving in phosphate buffer (PBS).

Molecular mechanisms behind BRACO19 and human telomeric G-quadruplex interaction.

Human telomeres (HTs) can form DNA G-quadruplex (G4), an attractive target for anticancer and antiviral drugs. HT-G4s exhibit inherent structural polymorphism, posing challenges for understanding their specific recognition by ligands. Here, we aim to explore the impact of different topologies within a small segment of the HT (Tel22) on its interaction with BRACO19, a rationally designed G4 ligand with high quadruplex affinity, already employed in in-vivo treatments.

Dynamic Personality of Proteins and Effect of the Molecular Environment.

Protein dynamics display distinct traits that are linked to their specific biological function. However, the interplay between intrinsic dynamics and the molecular environment on protein stability remains poorly understood. In this study, we investigate, by incoherent neutron scattering, the subnanosecond time scale dynamics of three model proteins: the mesophilic lysozyme, the thermophilic thermolysin, and the intrinsically disordered β-casein.

Ultraviolet Resonant Raman Scattering of Electrolyte Solutions.

Saltwater stands as the most prevalent liquid on Earth. Consequently, substantial interest has been directed toward its characterization, both as an independent system and as a solvent for complex structures such as biomacromolecules. In the last few decades, special emphasis was placed on the investigation of the hydration properties of ions for the fundamental role they play in numerous chemical processes.

Correction to "Electrospun Nanofibrous UV Filters with Bidirectional Actuation Properties Based on Salmon Sperm DNA/Silk Fibroin for Biomedical Applications".

[This corrects the article DOI: 10.1021/acsomega.3c04563.

Electrospun Nanofibrous UV Filters with Bidirectional Actuation Properties Based on Salmon Sperm DNA/Silk Fibroin for Biomedical Applications.

In this study, we dissolved degummed silk [i.e., silk fibroin (SF)] and salmon sperm deoxyribonucleic acid (DNA) in water and used a bioinspired spinning process to obtain an electrospun nanofibrous SF-based patch (ESF).

The hope and hype of ellagic acid and urolithins as ligands of SARS-CoV-2 Nsp5 and inhibitors of viral replication.

Non-structural protein 5 (Nsp5) is a cysteine protease that plays a key role in SARS-CoV-2 replication, suppressing host protein synthesis and promoting immune evasion. The investigation of natural products as a potential strategy for Nsp5 inhibition is gaining attention as a means of developing antiviral agents. In this work, we have investigated the physicochemical properties and structure-activity relationships of ellagic acid and its gut metabolites, urolithins A-D, as ligands of Nsp5.

Stacking Interactions and Flexibility of Human Telomeric Multimers.

G-quadruplexes (G4s) are helical four-stranded structures forming from guanine-rich nucleic acid sequences, which are thought to play a role in cancer development and malignant transformation. Most current studies focus on G4 monomers, yet under suitable and biologically relevant conditions, G4s undergo multimerization. Here, we investigate the stacking interactions and structural features of telomeric G4 multimers by means of a novel low-resolution structural approach that combines small-angle X-ray scattering (SAXS) with extremely coarse-grained (ECG) simulations.

Stability of Human Telomeric G-Quadruplexes Complexed with Photosensitive Ligands and Irradiated with Visible Light.

Guanine-rich DNA sequences can fold into non-canonical nucleic acid structures called G-quadruplexes (G4s). These nanostructures have strong implications in many fields, from medical science to bottom-up nanotechnologies. As a result, ligands interacting with G4s have attracted great attention as candidates in medical therapies, molecular probe applications, and biosensing.

Development of Salmon Sperm DNA/Regenerated Silk Bio-Based Films for Biomedical Studies on Human Keratinocyte HaCaT Cells under Solar Spectrum.

In this study, we fabricated adhesive patches from silkworm-regenerated silk and DNA to safeguard human skin from the sun's rays. The patches are realized by exploiting the dissolution of silk fibers (e.g.

Stabilization of the Dimeric State of SARS-CoV-2 Main Protease by GC376 and Nirmatrelvir.

The main protease (Mpro or 3CLpro) is an enzyme that is evolutionarily conserved among different genera of coronaviruses. As it is essential for processing and maturing viral polyproteins, Mpro has been identified as a promising target for the development of broad-spectrum drugs against coronaviruses. Like SARS-CoV and MERS-CoV, the mature and active form of SARS-CoV-2 Mpro is a dimer composed of identical subunits, each with a single active site.

Polymorphism and Ligand Binding Modulate Fast Dynamics of Human Telomeric G-Quadruplexes.

Telomeric G-quadruplexes (G4s) are promising targets in the design and development of anticancer drugs. Their actual topology depends on several factors, resulting in structural polymorphism. In this study, we investigate how the fast dynamics of the telomeric sequence AG3(TTAG3)3 (Tel22) depends on the conformation.

Role of fast dynamics in the complexation of G-quadruplexes with small molecules.

G-quadruplexes (G4s) formed by the human telomeric sequence AG (TTAG) (Tel22) play a key role in cancer and aging. We combined elastic incoherent neutron scattering (EINS) and quasielastic incoherent neutron scattering (QENS) to characterize the internal dynamics of Tel22 G4s and to assess how it is affected by complexation with two standard ligands, Berberine and BRACO19. We show that the interaction with the two ligands induces an increase of the overall mobility of Tel22 as quantified by the mean squared displacements (MSD) of hydrogen atoms.

The Combination of Molnupiravir with Nirmatrelvir or GC376 Has a Synergic Role in the Inhibition of SARS-CoV-2 Replication In Vitro.

Introduction: The development of effective vaccines has partially mitigated the trend of the SARS-CoV-2 pandemic; however, the need for orally administered antiviral drugs persists. This study aims to investigate the activity of molnupiravir in combination with nirmatrelvir or GC376 on SARS-CoV-2 to verify the synergistic effect. Methods: The SARS-CoV-2 strains 20A.

Microscale mechanochemical characterization of drying oil films by in situ correlative Brillouin and Raman spectroscopy.

Correlative Brillouin and Raman microspectroscopy (BRaMS) is applied for the in situ monitoring of the chemical and physical changes of linseed oil during polymerization. The viscoelastic properties of the drying oil throughout the phase transition were determined by Brillouin light scattering (BLS) and joined to the Raman spectroscopic information about the chemical process responsible for the oil hardening. A comparative study was then performed on an oil mock-up containing ZnO, one of the most common white pigments used in cultural heritage.

BCL2 G quadruplex-binding small molecules: Current status and prospects for the development of next-generation anticancer therapeutics.

B cell lymphoma 2 (BCL2) overexpression in a range of human tumors is often related to chemotherapy resistance and poor prognosis. GC-rich regions upstream of the P1 promoter in human BCL2 can form G-quadruplex (G4) structures through the stacking of four Hoogsteen-paired guanine bases. Stabilizing the G4 fold implies the inhibition of BCL2 expression and, thus, small molecules that selectively bind to the G4 are promising anticancer candidates.

Solvent Vibrations as a Proxy of the Telomere G-Quadruplex Rearrangements across Thermal Unfolding.

G-quadruplexes (G4s) are noncanonical forms of DNA involved in many key genome functions. Here, we exploited UV Resonance Raman scattering to simultaneously explore the vibrational behavior of a human telomeric G4 (Tel22) and its aqueous solvent as the biomolecule underwent thermal melting. We found that the OH stretching band, related to the local hydrogen-bonded network of a water molecule, was in strict relation with the vibrational features of the G4 structure as a function of temperature.

Hydration Dynamics of Model Peptides with Different Hydrophobic Character.

The multi-scale dynamics of aqueous solutions of the hydrophilic peptide -acetyl-glycine-methylamide (NAGMA) have been investigated through extended frequency-range depolarized light scattering (EDLS), which enables the broad-band detection of collective polarizability anisotropy fluctuations. The results have been compared to those obtained for -acetyl-leucinemethylamide (NALMA), an amphiphilic peptide which shares with NAGMA the same polar backbone, but also contains an apolar group. Our study indicates that the two model peptides induce similar effects on the fast translational dynamics of surrounding water.

Protein Hydration in a Bioprotecting Mixture.

We combined broad-band depolarized light scattering and infrared spectroscopies to study the properties of hydration water in a lysozyme-trehalose aqueous solution, where trehalose is present above the concentration threshold (30% in weight) relevant for biopreservation. The joint use of the two different techniques, which were sensitive to inter-and intra-molecular degrees of freedom, shed new light on the molecular mechanism underlying the interaction between the three species in the mixture. Thanks to the comparison with the binary solution cases, we were able to show that, under the investigated conditions, the protein, through preferential hydration, remains strongly hydrated even in the ternary mixture.

Porphyrin Binding and Irradiation Promote G-Quadruplex DNA Dimeric Structure.

Nucleic acid sequences rich in guanines can organize into noncanonical DNA G-quadruplexes (G4s) of variable size. The design of small molecules stabilizing the structure of G4s is a rapidly growing area for the development of novel anticancer therapeutic strategies and bottom-up nanotechnologies. Among a multitude of binders, porphyrins are very attractive due to their light activation that can make them valuable conformational regulators of G4s.

Thermoresponsivity of poly(N-isopropylacrylamide) microgels in water-trehalose solution and its relation to protein behavior.

Hypotheses: Additives are commonly used to tune macromolecular conformational transitions. Among additives, trehalose is an excellent bioprotectant and among responsive polymers, PNIPAM is the most studied material. Nevertheless, their interaction mechanism so far has only been hinted without direct investigation, and, crucially, never elucidated in comparison to proteins.