492 results on '"Francesco Zerbetto"'
Search Results
2. Daughter Coloured Noises: The Legacy of Their Mother White Noises Drawn from Different Probability Distributions
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Evangelos Bakalis, Francesca Lugli, and Francesco Zerbetto
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white noises ,probability distributions ,fractional calculus ,colours of noise ,classification of noises ,kurtosis ,Thermodynamics ,QC310.15-319 ,Mathematics ,QA1-939 ,Analysis ,QA299.6-433 - Abstract
White noise is fundamentally linked to many processes; it has a flat power spectral density and a delta-correlated autocorrelation. Operators acting on white noise can result in coloured noise, whether they operate in the time domain, like fractional calculus, or in the frequency domain, like spectral processing. We investigate whether any of the white noise properties remain in the coloured noises produced by the action of an operator. For a coloured noise, which drives a physical system, we provide evidence to pinpoint the mother process from which it came. We demonstrate the existence of two indices, that is, kurtosis and codifference, whose values can categorise coloured noises according to their mother process. Four different mother processes are used in this study: Gaussian, Laplace, Cauchy, and Uniform white noise distributions. The mother process determines the kurtosis value of the coloured noises that are produced. It maintains its value for Gaussian, never converges for Cauchy, and takes values for Laplace and Uniform that are within a range of its white noise value. In addition, the codifference function maintains its value for zero lag-time essentially constant around the value of the corresponding white noise.
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- 2023
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3. Exploiting Blood Transport Proteins as Carborane Supramolecular Vehicles for Boron Neutron Capture Therapy
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Tainah Dorina Marforio, Edoardo Jun Mattioli, Francesco Zerbetto, and Matteo Calvaresi
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carborane ,boron neutron capture therapy (BNCT) ,virtual screening ,docking ,reverse docking ,MD simulations ,Chemistry ,QD1-999 - Abstract
Carboranes are promising agents for applications in boron neutron capture therapy (BNCT), but their hydrophobicity prevents their use in physiological environments. Here, by using reverse docking and molecular dynamics (MD) simulations, we identified blood transport proteins as candidate carriers of carboranes. Hemoglobin showed a higher binding affinity for carboranes than transthyretin and human serum albumin (HSA), which are well-known carborane-binding proteins. Myoglobin, ceruloplasmin, sex hormone-binding protein, lactoferrin, plasma retinol-binding protein, thyroxine-binding globulin, corticosteroid-binding globulin and afamin have a binding affinity comparable to transthyretin/HSA. The carborane@protein complexes are stable in water and characterized by favorable binding energy. The driving force in the carborane binding is represented by the formation of hydrophobic interactions with aliphatic amino acids and BH-π and CH-π interactions with aromatic amino acids. Dihydrogen bonds, classical hydrogen bonds and surfactant-like interactions also assist the binding. These results (i) identify the plasma proteins responsible for binding carborane upon their intravenous administration, and (ii) suggest an innovative formulation for carboranes based on the formation of a carborane@protein complex prior to the administration.
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- 2023
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4. Human Serum Albumin–Oligothiophene Bioconjugate: A Phototheranostic Platform for Localized Killing of Cancer Cells by Precise Light Activation
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Andrea Cantelli, Marco Malferrari, Alice Soldà, Giorgia Simonetti, Sonny Forni, Edoardo Toscanella, Edoardo J. Mattioli, Francesco Zerbetto, Alberto Zanelli, Matteo Di Giosia, Mattia Zangoli, Giovanna Barbarella, Stefania Rapino, Francesca Di Maria, and Matteo Calvaresi
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Chemistry ,QD1-999 - Published
- 2021
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5. Identification of Blood Transport Proteins to Carry Temoporfin: A Domino Approach from Virtual Screening to Synthesis and In Vitro PDT Testing
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Alessia Marconi, Giulia Giugliano, Matteo Di Giosia, Tainah Dorina Marforio, Michele Trivini, Eleonora Turrini, Carmela Fimognari, Francesco Zerbetto, Edoardo Jun Mattioli, and Matteo Calvaresi
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docking ,virtual screening ,MD simulations ,MM-GBSA ,temoporfin (mTHPC) ,apomyoglobin ,Pharmacy and materia medica ,RS1-441 - Abstract
Temoporfin (mTHPC) is one of the most promising photosensitizers used in photodynamic therapy (PDT). Despite its clinical use, the lipophilic character of mTHPC still hampers the full exploitation of its potential. Low solubility in water, high tendency to aggregate, and low biocompatibility are the main limitations because they cause poor stability in physiological environments, dark toxicity, and ultimately reduce the generation of reactive oxygen species (ROS). Applying a reverse docking approach, here, we identified a number of blood transport proteins able to bind and disperse monomolecularly mTHPC, namely apohemoglobin, apomyoglobin, hemopexin, and afamin. We validated the computational results synthesizing the mTHPC-apomyoglobin complex (mTHPC@apoMb) and demonstrated that the protein monodisperses mTHPC in a physiological environment. The mTHPC@apoMb complex preserves the imaging properties of the molecule and improves its ability to produce ROS via both type I and type II mechanisms. The effectiveness of photodynamic treatment using the mTHPC@apoMb complex was then demonstrated in vitro. Blood transport proteins can be used as molecular “Trojan horses” in cancer cells by conferring mTHPC (i) water solubility, (ii) monodispersity, and (iii) biocompatibility, ultimately bypassing the current limitations of mTHPC.
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- 2023
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6. Deciphering the Reactive Pathways of Competitive Reactions inside Carbon Nanotubes
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Tainah Dorina Marforio, Michele Tomasini, Andrea Bottoni, Francesco Zerbetto, Edoardo Jun Mattioli, and Matteo Calvaresi
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nanoreactors ,carbon nanotubes ,nanoconfinement ,nucleophilic substitution SN2 ,elimination reaction E2 ,catalysis ,Chemistry ,QD1-999 - Abstract
Nanoscale control of chemical reactivity, manipulation of reaction pathways, and ultimately driving the outcome of chemical reactions are quickly becoming reality. A variety of tools are concurring to establish such capability. The confinement of guest molecules inside nanoreactors, such as the hollow nanostructures of carbon nanotubes (CNTs), is a straightforward and highly fascinating approach. It mechanically hinders some molecular movements but also decreases the free energy of translation of the system with respect to that of a macroscopic solution. Here, we examined, at the quantum mechanics/molecular mechanics (QM/MM) level, the effect of confinement inside CNTs on nucleophilic substitution (SN2) and elimination (syn-E2 and anti-E2) using as a model system the reaction between ethyl chloride and chloride. Our results show that the three reaction mechanisms are kinetically and thermodynamically affected by the CNT host. The size of the nanoreactor, i.e., the CNT diameter, represents the key factor to control the energy profiles of the reactions. A careful analysis of the interactions between the CNTs and the reactive system allowed us to identify the driving force of the catalytic process. The electrostatic term controls the reaction kinetics in the SN2 and syn/anti-E2 reactions. The van der Waals interactions play an important role in the stabilization of the product of the elimination process.
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- 2022
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7. Enhanced Uptake and Phototoxicity of C60@albumin Hybrids by Folate Bioconjugation
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Andrea Cantelli, Marco Malferrari, Edoardo Jun Mattioli, Alessia Marconi, Giulia Mirra, Alice Soldà, Tainah Dorina Marforio, Francesco Zerbetto, Stefania Rapino, Matteo Di Giosia, and Matteo Calvaresi
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C60 ,fullerenes ,human serum albumin ,folate ,photodynamic therapy ,phototheranostic platform ,Chemistry ,QD1-999 - Abstract
Fullerenes are considered excellent photosensitizers, being highly suitable for photodynamic therapy (PDT). A lack of water solubility and low biocompatibility are, in many instances, still hampering the full exploitation of their potential in nanomedicine. Here, we used human serum albumin (HSA) to disperse fullerenes by binding up to five fullerene cages inside the hydrophobic cavities. Albumin was bioconjugated with folic acid to specifically address the folate receptors that are usually overexpressed in several solid tumors. Concurrently, tetramethylrhodamine isothiocyanate, TRITC, a tag for imaging, was conjugated to C60@HSA in order to build an effective phototheranostic platform. The in vitro experiments demonstrated that: (i) HSA disperses C60 molecules in a physiological environment, (ii) HSA, upon C60 binding, maintains its biological identity and biocompatibility, (iii) the C60@HSA complex shows a significant visible-light-induced production of reactive oxygen species, and (iv) folate bioconjugation improves both the internalization and the PDT-induced phototoxicity of the C60@HSA complex in HeLa cells.
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- 2022
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8. Fullerenes against COVID-19: Repurposing C60 and C70 to Clog the Active Site of SARS-CoV-2 Protease
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Tainah Dorina Marforio, Edoardo Jun Mattioli, Francesco Zerbetto, and Matteo Calvaresi
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C60 ,C70 ,masitinib ,Mpro ,SARS-CoV-2 ,COVID-19 ,Organic chemistry ,QD241-441 - Abstract
The persistency of COVID-19 in the world and the continuous rise of its variants demand new treatments to complement vaccines. Computational chemistry can assist in the identification of moieties able to lead to new drugs to fight the disease. Fullerenes and carbon nanomaterials can interact with proteins and are considered promising antiviral agents. Here, we propose the possibility to repurpose fullerenes to clog the active site of the SARS-CoV-2 protease, Mpro. Through the use of docking, molecular dynamics, and energy decomposition techniques, it is shown that C60 has a substantial binding energy to the main protease of the SARS-CoV-2 virus, Mpro, higher than masitinib, a known inhibitor of the protein. Furthermore, we suggest the use of C70 as an innovative scaffold for the inhibition of SARS-CoV-2 Mpro. At odds with masitinib, both C60 and C70 interact more strongly with SARS-CoV-2 Mpro when different protonation states of the catalytic dyad are considered. The binding of fullerenes to Mpro is due to shape complementarity, i.e., vdW interactions, and is aspecific. As such, it is not sensitive to mutations that can eliminate or invert the charges of the amino acids composing the binding pocket. Fullerenic cages should therefore be more effective against the SARS-CoV-2 virus than the available inhibitors such as masinitib, where the electrostatic term plays a crucial role in the binding.
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- 2022
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9. Interactions between Endohedral Metallofullerenes and Proteins: The Gd@C60–Lysozyme Model
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Fabio Bologna, Edoardo Jun Mattioli, Andrea Bottoni, Francesco Zerbetto, and Matteo Calvaresi
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Chemistry ,QD1-999 - Published
- 2018
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10. Dissecting the Supramolecular Dispersion of Fullerenes by Proteins/Peptides: Amino Acid Ranking and Driving Forces for Binding to C60
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Tainah Dorina Marforio, Alessandro Calza, Edoardo Jun Mattioli, Francesco Zerbetto, and Matteo Calvaresi
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fullerene ,amino acids ,proteins ,peptides ,molecular dynamics simulations ,nanobiotechnology ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Molecular dynamics simulations were used to quantitatively investigate the interactions between the twenty proteinogenic amino acids and C60. The conserved amino acid backbone gave a constant energetic interaction ~5.4 kcal mol−1, while the contribution to the binding due to the amino acid side chains was found to be up to ~5 kcal mol−1 for tryptophan but lower, to a point where it was slightly destabilizing, for glutamic acid. The effects of the interplay between van der Waals, hydrophobic, and polar solvation interactions on the various aspects of the binding of the amino acids, which were grouped as aromatic, charged, polar and hydrophobic, are discussed. Although π–π interactions were dominant, surfactant-like and hydrophobic effects were also observed. In the molecular dynamics simulations, the interacting residues displayed a tendency to visit configurations (i.e., regions of the Ramachandran plot) that were absent when C60 was not present. The amino acid backbone assumed a “tepee-like” geometrical structure to maximize interactions with the fullerene cage. Well-defined conformations of the most interactive amino acids (Trp, Arg, Met) side chains were identified upon C60 binding.
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- 2021
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11. Analysis of Volcanic Thermohaline Fluctuations of Tagoro Submarine Volcano (El Hierro Island, Canary Islands, Spain)
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Anna Olivé Abelló, Beatriz Vinha, Francisco Machín, Francesco Zerbetto, Evangelos Bakalis, and Eugenio Fraile-Nuez
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Tagoro submarine volcano ,time series ,volcanic activity ,generalised moments method ,stochastic processes ,Geology ,QE1-996.5 - Abstract
Temperature and conductivity fluctuations caused by the hydrothermal emissions released during the degasification stage of the Tagoro submarine volcano (Canary Islands, Spain) have been analysed as a robust proxy for characterising and forecasting the activity of the system. A total of 21 conductivity-temperature-depth time series were gathered on a regular high-resolution grid over the main crater of Tagoro volcano. Temperature and conductivity time series, as manifestations of stochastic events, were investigated in terms of variance and analysed by the Generalised Moments Method (GMM). GMM provides the statistical moments, the structure functions of a process whose shape is an indicator of the underlying stochastic mechanisms and the state of activity of the submarine volcano. Our findings confirm an active hydrothermal process in the submarine volcano with a sub-normal behaviour resulting from anti-persistent fluctuations in time. Its hydrothermal emissions are classified as multifractal processes whose structure functions present a crossover between two time scales. In the shorter time scale, findings point to the multiplicative action of two random processes, hydrothermal vents, which carries those fluctuations driving the circulation over the crater, and the overlying aquatic environment. Given that both temperature and conductivity fluctuations are nonstationary, Tagoro submarine volcano can be characterised as an open system exchanging energy to its surroundings.
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- 2021
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12. The Hydrothermal Vent Field at the Eastern Edge of the Hellenic Volcanic Arc: The Avyssos Caldera (Nisyros)
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Ana Dura, Theo J. Mertzimekis, Paraskevi Nomikou, Andreas Gondikas, Martín Manuel Gómez Míguez, Evangelos Bakalis, and Francesco Zerbetto
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hydrothermal vent ,Nisyros ,Generalized Moments Method ,Geology ,QE1-996.5 - Abstract
Almost three-quarters of known volcanic activity on Earth occurs in underwater locations. The presence of active hydrothermal vent fields in such environments is a potential natural hazard for the environment, society, and economy. Despite its importance for risk assessment and risk mitigation, the monitoring of volcanic activity is impeded by the remoteness and the extreme conditions of many underwater volcanoes. The morphology and the activity of the submarine caldera, Avyssos, at the northern part of Nisyros volcano in the South Aegean Sea (Greece), were studied using a remotely operated underwater vehicle. The recorded time series of temperature and conductivity over the submarine volcano have been analyzed in terms of the Generalized Moments Method. This type of analysis can be used as an indicator for the state of activity of a submarine volcano. Here, we expand the work conducted for the first time in 2018. We present the findings of the geological exploration and the mathematical analysis, obtained from the data collected in October 2010. The temperature and conductivity time series show minor fluctuations in a rather stable environment. Based on these results, the impact of developing appropriate mechanisms and policies to avoid the associated natural hazard is expected to be important.
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- 2021
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13. Customizing Properties of β-Chitin in Squid Pen (Gladius) by Chemical Treatments
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Alessandro Ianiro, Matteo Di Giosia, Simona Fermani, Chiara Samorì, Marianna Barbalinardo, Francesco Valle, Graziella Pellegrini, Fabio Biscarini, Francesco Zerbetto, Matteo Calvaresi, and Giuseppe Falini
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β-chitin ,hierarchical structure ,squid pen ,deacetylation ,mechanical properties ,wettability ,porosity ,Biology (General) ,QH301-705.5 - Abstract
The squid pen (gladius) from the Loligo vulgaris was used for preparation of β-chitin materials characterized by different chemical, micro- and nano-structural properties that preserved, almost completely the macrostructural and the mechanical ones. The β-chitin materials obtained by alkaline treatment showed porosity, wettability and swelling that are a function of the duration of the treatment. Microscopic, spectroscopic and synchrotron X-ray diffraction techniques showed that the chemical environment of the N-acetyl groups of the β-chitin chains changes after the thermal alkaline treatment. As a consequence, the crystalline packing of the β-chitin is modified, due to the intercalation of water molecules between β-chitin sheets. Potential applications of these β-chitin materials range from the nanotechnology to the regenerative medicine. The use of gladii, which are waste products of the fishing industry, has also important environmental implications.
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- 2014
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14. Temperature and Conductivity as Indicators of the Morphology and Activity of a Submarine Volcano: Avyssos (Nisyros) in the South Aegean Sea, Greece
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Evangelos Bakalis, Theo J. Mertzimekis, Paraskevi Nomikou, and Francesco Zerbetto
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generalized moments method ,time series ,submarine volcano ,Nisyros ,Geology ,QE1-996.5 - Abstract
The morphology and the activity of a submarine caldera, Avyssos, at the northern part of Nisyros volcano in the South Aegean Sea (Greece), has been studied by means of remotely-operated underwater vehicle dives. The recorded time series of temperature and conductivity over the submarine volcano have been analyzed in terms of the generalized moments method. The findings of the mathematical analysis shed light on the volcanic activity, but also on the morphology (shape) of the submarine volcano. The conductivity time series indicates that the volcano is at rest, in agreement with other types of observations. On the other hand, temperature fluctuations, which in general describe a multifractal process, show that the submarine caldera operates as an open system that interacts with its surroundings. This type of analysis can be used as an indicator for the state of activity and the morphological structure (closed or open system) of a submarine volcano.
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- 2018
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15. Common Force Field Thermodynamics of Cholesterol
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Francesco Giangreco, Eiji Yamamoto, Yoshinori Hirano, Milan Hodoscek, Volker Knecht, Matteo di Giosia, Matteo Calvaresi, Francesco Zerbetto, Kenji Yasuoka, Tetsu Narumi, Masato Yasui, and Siegfried Höfinger
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Technology ,Medicine ,Science - Abstract
Four different force fields are examined for dynamic characteristics using cholesterol as a case study. The extent to which various types of internal degrees of freedom become thermodynamically relevant is evaluated by means of principal component analysis. More complex degrees of freedom (angle bending, dihedral rotations) show a trend towards force field independence. Moreover, charge assignments for membrane-embedded compounds are revealed to be critical with significant impact on biological reasoning.
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- 2013
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16. Mechanical tightening of a synthetic molecular knot
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Matteo Calvaresi, Anne-Sophie Duwez, David A. Leigh, Damien Sluysmans, Yiwei Song, Francesco Zerbetto, and Liang Zhang
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General Chemical Engineering ,Biochemistry (medical) ,Materials Chemistry ,Environmental Chemistry ,General Chemistry ,Biochemistry - Published
- 2023
17. Hydrodynamic Fluctuations in the Presence of One Parameter Mittag-Leffler Friction
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Evangelos Bakalis and Francesco Zerbetto
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- 2023
18. Viscoelasticity and Noise Properties Reveal the Formation of Biomemory in Cells
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A.C. Cefalas, Vassilios Gavriil, Evangelos Bakalis, Evangelia Sarantopoulou, Zoe Kollia, Francesco Zerbetto, Bakalis E., Gavriil V., Cefalas A.-C., Kollia Z., Zerbetto F., and Sarantopoulou E.
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Materials science ,Viscosity ,Mathematical analysis ,Phase (waves) ,Alternaria ,Spectral density ,Nanoindentation ,Microscopy, Atomic Force ,Noise (electronics) ,Article ,Elasticity ,Viscoelasticity ,Surfaces, Coatings and Films ,Time derivative ,Materials Chemistry ,Exponent ,Relaxation (physics) ,Physical and Theoretical Chemistry ,Scaling - Abstract
Living cells are neither perfectly elastic nor liquid and return a viscoelastic response to external stimuli. Nanoindentation provides force distance curves allowing the investigation of cell mechanical properties, and yet, these curves can differ from point to point on cell surface revealing its inhomogeneous character. In the present work, we propose a mathematical method to estimate both viscoelastic and noise properties of cells, as these are depicted on the values of the scaling exponents of relaxation function and power spectral density respectively. The method uses as input the time derivative of the response force in a nanoindentation experiment. Generalized moments method and/or rescaled range analysis are used to study the resulting time series depending on their non-stationary or stationary nature. We conducted experiments in livingUlocladium Chartarumspores. We found that spores, in the approaching phase present a viscoelastic behavior with the corresponding scaling exponent in the range 0.25-0.52, and in the retracting phase present a liquid-like behavior with exponents in the range 0.67-0.85. This substantial difference of the scaling exponents in the two phases suggests the formation of biomemory as response of the spores to the indenting AFM mechanical stimulus. The retracting phase may be described as a process driven by bluish noises, while the approaching one is driven by persistent noise.
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- 2021
19. Janus-Type Dendrimers Based on Highly Branched Fluorinated Chains with Tunable Self-Assembly and 19F Nuclear Magnetic Resonance Properties
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Marta Rosati, Angela Acocella, Andrea Pizzi, Giorgio Turtù, Giulia Neri, Nicola Demitri, null Nonappa, Giuseppina Raffaini, Bertrand Donnio, Francesco Zerbetto, Francesca Baldelli Bombelli, Gabriella Cavallo, Pierangelo Metrangolo, Tampere University, Materials Science and Environmental Engineering, and Marta Rosati, Angela Acocella, Andrea Pizzi, Giorgio Turtù, Giulia Neri, Nicola Demitri, Nonappa, Giuseppina Raffaini, Bertrand Donnio, Francesco Zerbetto, Francesca Baldelli Bombelli, Gabriella Cavallo, Pierangelo Metrangolo
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Polymers and Plastics ,PHASE ,Organic Chemistry ,221 Nanotechnology ,POLYMORPHISM ,Inorganic Chemistry ,SUPRAMOLECULAR DENDRIMER, DRUG-DELIVERY, PHASE, CHEMISTRY, DESIGN, AMPHIPHILE, MRI, POLYMORPHISM, TRANSITION, POLYMERS ,DESIGN ,CHEMISTRY ,216 Materials engineering ,Materials Chemistry ,DRUG-DELIVERY ,POLYMERS ,SUPRAMOLECULAR DENDRIMER AMPHIPHILE MRI POLYMORPHISM TRANSITION COARSE-GRAINED MODELING ,SUPRAMOLECULAR DENDRIMER ,AMPHIPHILE ,TRANSITION ,MRI - Abstract
Tuning the self-assembly of dendritic amphiphiles represents a major challenge for the design of advanced nanomaterials for biomimetic applications. The morphology of the final aggregates, in fact, critically depends on the primary structure of the dendritic building blocks as well as the environmental conditions. Here we report a new family of fluorinated Janus-type dendrimers (FJDs), based on a short-chain and branched fluorinated synthon with 27 magnetically equivalent fluorine atoms, linked to bis-MPA polyester dendrons of different generations. Increasing size, flexibility, and number of peripheral hydroxyl groups, we observed a peculiar self-assembly behavior in bulk and in aqueous media as a consequence of the subtle balance between their fluorinated and hydrophilic portions. The lowest generation FJDs formed spherical nanoparticles in water, e.g., micelles, showing a single 19F NMR peak with good signal-to-noise ratio and over time stability, making them promising as 19F-MRI traceable probes. The highest generation FJD, instead, presented an interesting morphological transition from multilamellar dendrimersomes to tubules as a consequence of a subtle balance of intra- and intermolecular forces that compete at the interface. Interestingly, a reduction of the local mobility of CF3 groups passing from dendrimersomes to tubules switches off the 19F NMR signal. The transition mechanism has been rationalized by coarse-grain simulations as well as demonstrated by using cosolvents of different nature (e.g., fluorinated) that promote conformational changes, ultimately reflected in the self-assembly behavior. Short and branched fluorinated chains have here been demonstrated as new moieties for the design of FJDs with tunable self-assembly behavior for potential applications as biocompatible 19F MRI probes in the construction of theranostic platforms. publishedVersion
- Published
- 2022
20. Incorporation of Molecular Nanoparticles Inside Proteins: The Trojan Horse Approach in Theranostics
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Matteo Calvaresi, Francesco Zerbetto, Matteo Di Giosia, Di Giosia, M, Zerbetto, F, and Calvaresi, M
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Polymers and Plastics ,Chemistry ,Materials Science (miscellaneous) ,Materials Chemistry ,Chemical Engineering (miscellaneous) ,Trojan horse ,Nanoparticle ,fullerene, carborane, gold nanocluster, protein, peptide, theranostics ,Nanotechnology - Abstract
CONSPECTUS: Molecular nanoparticles, MNPs, characterized by well-defined chemical formulas, structures, and sizes can interact with a variety of proteins. Fullerenes, carboranes, and gold nanoclusters well represent the diversity of MNPs properties available in nanoscience. They can have diameters smaller than 1.5 nm, be hydrophilic or hydrophobic, and can use a paraphernalia of means to establish local and global interactions with the amino acidic residues of proteins. Proteins, endowed as they are with an assortment of pockets, crevices, and gaps are natural supramolecular hosts to incorporate/hide/transport MNPs directly in water with a facile and "green" approach.This Account identifies and discusses the rules that govern the interactions and binding between MNPs and proteins. Fullerenes are composed solely by carbon atoms arranged to form hollow polyhedra. Hydrophobic interactions occur between aliphatic residues and the fullerene surface. The amino acids most effectively interacting with fullerenes are aromatic residues that establish p-p stacking interactions with the cage. Amphiphilic and charged residues produce also cation-p, anion-p, and surfactant-like interactions with the cages.Carboranes are composed of boron, carbon, and hydrogen atoms, also arranged to form cages. They are hydrophobic with unusual properties originating from the presence of boron atoms. Hydride-like hydrogens bound to the boron atoms govern carborane chemistry. These negatively charged hydrogens do not participate in classic hydrogen bonding with water and promote hydrophobic interactions with proteins. On the contrary, the electronegativity of these hydrogens drives the formation of unconventional dihydrogen bonds with the acidic hydrogen atoms of positively charged amino acid. Carboranes also establish C-H center dot center dot center dot p and B-H center dot center dot center dot p interactions with aromatic residues.Gold nanoclusters, AuNCs, are synthesizable with atomically precise stoichiometry. Amino acid residues with sulfur atoms or with nitrogen-containing heterocycles are the strongest Au binders. The proteins can act as supramolecular hosts but also as templates for the synthesis of AuNCs directly inside the protein core. Of the pristine amino acids, tryptophan, tyrosine, phenylalanine, and aspartic acid are the most efficient reducing groups. In a peptide sequence, the best Au-reducing moieties are obtained by nitrogencontaining residue such as glutamine, asparagine, arginine, and lysine. The investigation of the interactions between AuNCs and proteins therefore adds further complexity with respect to that of fullerenes and carboranes. The selection of the host proteins should consider that they will have to contain active sites for metal ion accumulation and ion reduction where AuNC can form and stabilize. This Account further discusses the hybridization of MNPs with proteins in view of creating innovative multifunctional theranostic platforms where the role of proteins is akin to that of "Trojan Horses" since they can (i) hide the MNPs, (ii) control their cellular uptake, (iii) drive their crossing of physiological barriers, and (iv) ultimately govern their biological fate.
- Published
- 2021
21. Universal Markers Unveil Metastatic Cancerous Cross-Sections at Nanoscale
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Evangelos Bakalis, Angelo Ferraro, Vassilios Gavriil, Francesco Pepe, Zoe Kollia, Alkiviadis-Constantinos Cefalas, Umberto Malapelle, Evangelia Sarantopoulou, Giancarlo Troncone, Francesco Zerbetto, Bakalis, Evangelo, Ferraro, Angelo, Gavriil, Vassilio, Pepe, Francesco, Kollia, Zoe, Cefalas, Alkiviadis-Constantino, Malapelle, Umberto, Sarantopoulou, Evangelia, Troncone, Giancarlo, and Zerbetto, Francesco
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Cancer Research ,metastatic cancer ,Oncology ,multifractal analysis ,atomic force microscopy imaging - Abstract
The characterization of cancer histological sections as metastatic, M, or not-metastatic, NM, at the cellular size level is important for early diagnosis and treatment. We present timely warning markers of metastasis, not identified by existing protocols and used methods. Digitized atomic force microscopy images of human histological cross-sections of M and NM colorectal cancer cells were analyzed by multifractal detrended fluctuation analysis and the generalized moments method analysis. Findings emphasize the multifractal character of all samples and accentuate room for the differentiation of M from NM cross-sections. Two universal markers emphatically achieve this goal performing very well: (a) the ratio of the singularity parameters (left/right), which are defined relative to weak/strong fluctuations in the multifractal spectrum, is always greater than 0.8 for NM tissues; and (b) the index of multifractality, used to classify universal multifractals, points to log-normal distribution for NM and to log-Cauchy for M tissues. An immediate large-scale screening of cancerous sections is doable based on these findings.
- Published
- 2022
22. GPU-accelerated computation of electron transfer.
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Siegfried Höfinger, Angela Acocella, Sergiu C. Pop, Tetsu Narumi, Kenji Yasuoka, Titus Beu, and Francesco Zerbetto
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- 2012
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23. Fast Calculation of Electrostatic Potentials on the GPU or the ASIC MD-GRAPE-3.
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Tetsu Narumi, Kenji Yasuoka, Makoto Taiji, Francesco Zerbetto, and Siegfried Höfinger
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- 2011
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24. In Silico Carborane Docking to Proteins and Potential Drug Targets.
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Matteo Calvaresi and Francesco Zerbetto
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- 2011
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25. Inhibition of α-chymotrypsin by pristine single-wall carbon nanotubes: Clogging up the active site
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Matteo Di Giosia, Haifang Wang, Qianqian Su, Tainah Dorina Marforio, Andrea Cantelli, Francesco Zerbetto, Francesco Valle, Matteo Calvaresi, Di Giosia M., Marforio T.D., Cantelli A., Valle F., Zerbetto F., Su Q., Wang H., and Calvaresi M.
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Molecular dynamic ,Serine Proteinase Inhibitors ,Surface Properties ,Carbon nanotubes ,alpha-Chymotrypsin ,02 engineering and technology ,Carbon nanotube ,Molecular Dynamics Simulation ,Molecular dynamics ,010402 general chemistry ,01 natural sciences ,law.invention ,Biomaterials ,Colloid and Surface Chemistry ,law ,Catalytic triad ,Chymotrypsin ,Particle Size ,Nano-bio interface ,Binding site ,Protein secondary structure ,Inhibition ,Binding Sites ,biology ,Nanotubes, Carbon ,Chemistry ,Protein ,Proteins ,Substrate (chemistry) ,Active site ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Crystallography ,biology.protein ,α-Chymotrypsin ,Fullerenes ,0210 nano-technology - Abstract
The preferred spatial orientation of single-wall carbon nanotubes (SWCNTs) in their interaction with enzymes determines their behavior either as nano-supports or as inhibitors. alpha-chymotrypsin (alpha-CT) is considered a serine protease model for studying nanomaterial/proteases interactions. The interaction of alpha-CT with pristine single-wall carbon nanotubes is still unknown. Here alpha-CT/SWCNT hybrids are synthesized and characterized. Spectroscopic, microscopic and kinetic measurements, coupled to molecular dynamics simulations, provide a detailed description of the interaction between alpha-CT and SWCNTs. The SWCNT binding pocket was unambiguously identified. A perfect match is observed with the crevice structure of the alpha-CT substrate binding pocket. The activity of alpha-CT, upon SWCNT binding, is dramatically reduced, as expected by the interaction of the SWCNT in the active site of the protein. it-it stacking between aromatic residues and the conjugated surface of SWCNT governs alpha-CT/SWCNT interactions. An important role in the bonding appears also for purely hydrophobic residues and with residues able to establish surfactant-like interactions. The secondary structure of alpha-CT and the catalytic triad structure are not perturbed by the complex formation, on the contrary the volume of the substrate binding pocket is strongly reduced by SWCNT binding because SWCNT occupies the alpha-CT substrate binding site, clogging the active site. (C) 2020 Elsevier Inc. All rights reserved.
- Published
- 2020
26. Complex Nanoparticle Diffusional Motion in Liquid-Cell Transmission Electron Microscopy
- Author
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Evangelos Bakalis, Chiwoo Park, Maria Vratsanos, Lucas R. Parent, Nathan C. Gianneschi, Francesco Zerbetto, Bakalis, E, Parent, LR, Vratsanos, M, Park, C, Gianneschi, NC, and Zerbetto, F
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Materials science ,Orientation (computer vision) ,Anomalous diffusion ,Nanoparticle ,Motion (geometry) ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Article ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Fluxes, Diffusion, Micelles, Chemical structure, Irradiation ,General Energy ,Transmission electron microscopy ,Liquid cell ,Physical and Theoretical Chemistry ,Diffusion (business) ,0210 nano-technology ,Biological system ,Nanoscopic scale - Abstract
Liquid-cell transmission electron microscopy (LCTEM) is a powerful in situ videography technique that has the potential to allow us to observe solution-phase dynamic processes at the nanoscale, including imaging the diffusion and interaction of nanoparticles. Artefactual effects imposed by the irradiated and confined liquid-cell vessel alter the system from normal "bulk-like" behavior in multiple ways. These artefactual LCTEM effects will leave their fingerprints in the motion behavior of the diffusing objects, which can be revealed through careful analysis of the object-motion trajectories. Improper treatment of the motion data can lead to erroneous descriptions of the LCTEM system's conditions. Here, we advance our anomalous diffusion object-motion analysis (ADOMA) method to extract a detailed description of the liquid-cell system conditions during any LCTEM experiment by applying a multistep analysis of the data and treating the x/y vectors of motion independently and in correlation with each other and with the object's orientation/angle.
- Published
- 2020
27. Electron Dynamics with Explicit-Time Density Functional Theory of the [4+2] Diels–Alder Reaction
- Author
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Angela Acocella, Andrea Bottoni, Matteo Calvaresi, Francesco Zerbetto, Tainah Dorina Marforio, Acocella A., Marforio T.D., Calvaresi M., Bottoni A., and Zerbetto F.
- Subjects
010304 chemical physics ,Chemistry ,Electron dynamics ,01 natural sciences ,Article ,Computer Science Applications ,Lewis structure ,symbols.namesake ,Computational chemistry ,0103 physical sciences ,Electron dynamics, Quantum mechanics, Diels-Alder, Resonance Theory ,Diels alder ,Resonance theory ,symbols ,Density functional theory ,Physical and Theoretical Chemistry ,Diels–Alder reaction - Abstract
The prototype Diels-Alder (DA) reaction between butadiene and ethene (system 1) and the DA reaction involving 1-methoxy-butadiene and cyano-ethylene (system 2) are investigated with an explicit-time-dependent Density Functional Theory approach. Bond orders and atomic net charges obtained in the dynamics at the transition state geometry and along the reaction coordinate toward reactants are used to provide a picture of the process in terms of VB/Lewis resonance structures that contribute to a resonance hybrid. The entire dynamics can be divided into different domains (reactant-like, product-like, and transition state domains) where different Lewis resonance structures contribute with different weights. The relative importance of these three domains varies along the reaction coordinate. In addition to the usual reactant-like and product-like covalent Lewis structures, ionic Lewis structures have non-negligible weights. In system 2, the electron-donor OCH3 on the diene and the electron-acceptor CN on the dienophile make more important the contributions of ionic Lewis structures that stabilize the transition state and determine the decrease of the reaction barrier with respect to system 1.
- Published
- 2020
28. Photothermal motion: effect of low-intensity irradiation on the thermal motion of organic nanoparticles
- Author
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Moreno Guernelli, Evangelos Bakalis, Alexandra Mavridi-Printezi, Vasilis Petropoulos, Giulio Cerullo, Francesco Zerbetto, Marco Montalti, Guernelli, Moreno, Bakalis, Evangelo, Mavridi-Printezi, Alexandra, Petropoulos, Vasili, Cerullo, Giulio, Zerbetto, Francesco, and Montalti, Marco
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low-intensity irradiation, thermal motion, organic nanoparticles ,General Materials Science - Abstract
The effect of local photo-triggered heat release on the motion of organic nanopartcles (NP), a process that is itself thermal, is largely unexplored under low-intensity irradiation. Here, we develop organic NP specifically tailored for this study and demonstrate, comparing three different irradiation intensity regimes, that indeed the NP undergo "acceleration" upon light absorption (Photothermal Motion). These NP have a well-defined chemical composition and extremely high molar absorbance coefficient, and upon excitation, they deactivate mostly non radiatively with localized heat dissipation. The residual fluorescence efficiency is high enough to allow the detection of their trajectory in a simple wide field fluorescence microscope under low-intensity irradiation, a typical condition for NP bio-applications. The NP were characterized in detail from the photophysical point of view using UV-VIS absorption, steady-state and time-resolved fluorescence spectroscopy and ultra-fast transient absorption (UF-TA). A detailed analysis of the trajectories of the NP reveals a strong dependency of the diffusion coefficient on the irradiation intensity even in a low power regime. This behavior demonstrates the inhomogeneity of the environment surrounding the NP as a result of local heat generation. Upon irradiation, the effective temperature increase, that emerges from the analysis, is much larger than that expected for plasmonic NP. Anomalous diffusion object-motion analysis (ADOMA) revealed that, in the more intense irradiation regime, the motion of the NP is a fractional Brownian motion, which is a simple generalization of Brownian motion where the steps are not independent of each other.
- Published
- 2022
29. Effect of the Embedment of Carbon Doped Nanocomposites in a Real Matrix on the Enhanced Photocatalytic Activity
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Arianna Menichetti, Moreno Guernelli, Gloria Guidetti, Andrea Cacciatore, Giampiero De Notarpietro, Marcello Molfetta, Claudia Capone, Matteo Calvaresi, Giuseppe Falini, Francesco Zerbetto, Iryna Polishchuk, Boaz Pokroy, Marco Goisis, Marco Montalti, Menichetti, Arianna, Guernelli, Moreno, Guidetti, Gloria, Cacciatore, Andrea, De Notarpietro, Giampiero, Molfetta, Marcello, Capone, Claudia, Calvaresi, Matteo, Falini, Giuseppe, Zerbetto, Francesco, Polishchuk, Iryna, Pokroy, Boaz, Goisis, Marco, and Montalti, Marco
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History ,Photocatalysi ,Polymers and Plastics ,Cement matrix ,Titanium dioxide ,Graphene ,Business and International Management ,Air decontamination ,Industrial and Manufacturing Engineering - Abstract
Solar light can be used by semiconductor nanocrystals as a free and largely available source of energy to transform air pollutants into non-volatile less harmful chemicals. The efficiency of this process can be enhanced by doping the semiconductor with carbon-based materials, such as graphene. Nevertheless, such an increased activity has been reported (i) for nanocomposite photocatalysts produced on the research laboratory scale, (ii) analyzing their performance as self-standing photocatalysts and not after incorporation into “real” matrixes (e.g. building materials) and (iii) typically using model target pollutants instead of “real” hazardous ones. Here we describe the large-scale preparation of two series of carbon based photocatalysts starting from commercial materials and we demonstrate their superior photocatalytic activity in degrading important air pollutants as nitrogen oxides, compared to undoped photocatalysts. The photocatalytic activity was evaluated by NOx abatement adopting the continuous flow procedure and the apparatus reported in the Italian standard UNI 11,247. Best performing materials were incorporated into two different inorganic matrixes (cement and lime). In both cases, the superior photocatalytic performances were maintained. An improvement up to 42±7% of the photocatalytic activity was measured in the case of a cement sample for a carbon-doped photocatalyst with respect to bare TiO2 . The materials were characterized by UV-Vis spectroscopy, high resolution powder X-ray diffraction (HR-PXRD), high-resolution scanning electron microscopy (HR-SEM) energy-dispersive X-ray spectroscopy (EDS) and micro-Raman.
- Published
- 2022
30. Laser Assisted Bioprinting of laminin on biodegradable PLGA substrates: Effect on neural stem cell adhesion and differentiation
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Silvia Tortorella, Pierpaolo Greco, Francesco Valle, Marianna Barbalinardo, Giulia Foschi, Francesca Lugli, Marco Dallavalle, Francesco Zerbetto, Carlo Augusto Bortolotti, Fabio Biscarini, Tortorella, S., Greco, P., Valle, F., Barbalinardo, M., Foschi, G., Lugli, F., Dallavalle, M., Zerbetto, F., Bortolotti, C. A., and Biscarini, F.
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Neuron differentiation ,Cell culture spatial statistic ,Atomic Force Microscopy ,Biodegradable Scaffolds ,Cell Culture Spatial Statistics ,Chemical Cues ,Coarse Grained Cells Modelling ,Laminin ,Laser Assisted Bioprinting ,Neuron Differentiation ,Biomedical Engineering ,Coarse grained cells modelling ,Atomic force microscopy ,Biodegradable scaffolds ,Cell culture spatial statistics ,Chemical cues ,Laser assisted bioprinting ,Computer Science Applications ,NO ,Biodegradable scaffold ,Biotechnology - Abstract
Laser Assisted Bioprinting (LAB) is recognized to be an enabling and versatile microfabrication technology for regenerative medicine and artificial tissue engineering. Current bioprinting concentrates on a layer-by-layer approach to print cells in consecutive stacks or nets, to recreate specialized tissue functions with a top-down approach. This synthering of proximal cells however reduces the long range correlation of tissue parenchyma and stroma given by natural development, as result of cells mobility and signaling. In this work, laminin, one of the main components of brain extracellular matrix is deposited by LAB on a biodegradable scaffold made of poly (lactic-co-glycolic acid) (PLGA), providing chemical cues for the adhesion and differentiation of neural stem cells NE-4C induced by retinoic acid. Surface roughness and LAB induced aggregates promote the initial adhesion of neuronal stem cells to the PLGA substrate and influence the formation of clusters and interconnection between them. The amount of laminin delivered inside the spot area may be controlled down to sub-monolayer coverage and a positive correlation between the laminin spots and soma of trafficking cells is demonstrated, also by computational modelling. Anisotropic orientation of neurite outgrowth is induced upon differentiation, up to 70% of processes protruding from stem cell clusters. The comparative analysis shows that the topological cue plays a major role in enhabling cluster formation on the scaffold, but the bioprinted laminin spots appear to be regulating the strength of connection between them, opening the way to control the functional morphology of artificial neural tissue constructs.
- Published
- 2022
31. Dissecting the Supramolecular Dispersion of Fullerenes by Proteins/Peptides: Amino Acid Ranking and Driving Forces for Binding to C60
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Edoardo Jun Mattioli, Matteo Calvaresi, Alessandro Calza, Tainah Dorina Marforio, Francesco Zerbetto, Marforio T.D., Calza A., Mattioli E.J., Zerbetto F., and Calvaresi M.
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QH301-705.5 ,Stereochemistry ,Supramolecular chemistry ,nanobiotechnology ,Catalysis ,Article ,Inorganic Chemistry ,Hydrophobic and Hydrophilic Interaction ,Molecular dynamics ,symbols.namesake ,Molecular dynamics simulation ,Side chain ,Nanobi-otechnology ,Biology (General) ,Physical and Theoretical Chemistry ,QD1-999 ,Molecular Biology ,Spectroscopy ,chemistry.chemical_classification ,amino acids ,MM/GBSA ,Chemistry ,Protein ,fullerene ,Organic Chemistry ,Tryptophan ,General Medicine ,Glutamic acid ,molecular dynamics simulations ,proteins ,Computer Science Applications ,Amino acid ,Amino Acid ,nanobio interface ,Peptide ,symbols ,peptides ,Fullerenes ,van der Waals force ,Hydrophobic and Hydrophilic Interactions ,π–π stacking ,Ramachandran plot - Abstract
Molecular dynamics simulations were used to quantitatively investigate the interactions between the twenty proteinogenic amino acids and C60. The conserved amino acid backbone gave a constant energetic interaction ~5.4 kcal mol−1, while the contribution to the binding due to the amino acid side chains was found to be up to ~5 kcal mol−1 for tryptophan but lower, to a point where it was slightly destabilizing, for glutamic acid. The effects of the interplay between van der Waals, hydrophobic, and polar solvation interactions on the various aspects of the binding of the amino acids, which were grouped as aromatic, charged, polar and hydrophobic, are discussed. Although π–π interactions were dominant, surfactant-like and hydrophobic effects were also observed. In the molecular dynamics simulations, the interacting residues displayed a tendency to visit configurations (i.e., regions of the Ramachandran plot) that were absent when C60 was not present. The amino acid backbone assumed a “tepee-like” geometrical structure to maximize interactions with the fullerene cage. Well-defined conformations of the most interactive amino acids (Trp, Arg, Met) side chains were identified upon C60 binding.
- Published
- 2021
32. Functionalization Pattern of Graphene Oxide Sheets Controls Entry or Produces Lipid Turmoil in Phospholipid Membranes
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Andrea Bottoni, Marco Dallavalle, Matteo Calvaresi, Francesco Zerbetto, and Marco Dallavalle, Andrea Bottoni, Matteo Calvaresi, Francesco Zerbetto
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Materials science ,Phospholipid ,Oxide ,02 engineering and technology ,Molecular Dynamics Simulation ,010402 general chemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Molecular dynamics ,law ,General Materials Science ,membrane ,Phospholipids ,phospholipid ,Double layer (biology) ,Graphene ,molecular dynamic ,coarse grain modeling ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Hydrophilic Interactions ,Membrane ,chemistry ,Chemical engineering ,nanotoxicity ,graphene oxide ,Surface modification ,Graphite ,lipids (amino acids, peptides, and proteins) ,Materials Science (all) ,0210 nano-technology ,Hydrophobic and Hydrophilic Interactions - Abstract
Molecular dynamics, coarse-grained to the level of hydrophobic and hydrophilic interactions, shows that graphene oxide sheets, GOSs, can pierce through the phospholipid membrane and navigate the double layer only if the hydrophilic groups are randomly dispersed in the structure. Their behavior resembles that found in similar calculations for pristine graphene sheets. If the oxidation is located at the edge of the sheets, GOSs hover over the membrane and trigger a major reorganization of the lipids. The reorganization is the largest when the radius of the edge-functionalized sheet is similar to the length of the lipophilic chain of the lipids. In the reorganization, the heads of the lipid chains form dynamical structures that pictorially resemble the swirl of water flowing down a drain. All effects maximize the interaction between hydrophobic moieties on the one hand and lipophilic fragments on the other and are accompanied by a large number of lipid flip-flops. Possible biological consequences are discussed.
- Published
- 2018
33. Proteins as supramolecular hosts for C60: a true solution of C60 in water
- Author
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Giuseppe Falini, Nico A. J. M. Sommerdijk, Andrea Cantelli, Paul H. H. Bomans, Francesco Paolucci, Francesco Zerbetto, Matteo Di Giosia, Matteo Calvaresi, Giuseppe Guarracino, Andrea Bottoni, Paola Franchi, Heiner Friedrich, Stefania Rapino, Alice Soldà, Francesco Valle, Marco Lucarini, Materials and Interface Chemistry, Matteo Di Giosia, Paul H. H. Bomans, Andrea Bottoni, Andrea Cantelli, Giuseppe Falini, Paola Franchi, Giuseppe Guarracino, Heiner Friedrich, Marco Lucarini, Francesco Paolucci, Stefania Rapino, Nico A. J. M. Sommerdijk, Alice Soldà, Francesco Valle, Francesco Zerbetto, Matteo Calvaresi, DIP. DI BIOCHIMICA 'MORUZZI', DIPARTIMENTO DI CHIMICA 'GIACOMO CIAMICIAN', Facolta' di FARMACIA, Facolta' di SCIENZE MATEMATICHE FISICHE e NATURALI, Da definire, and AREA MIN. 03 - Scienze chimiche
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Aqueous solution ,Fullerene ,Fullerenes/chemistry ,Spin trapping ,fullerene ,Muramidase/chemistry ,Supramolecular chemistry ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,proteins ,0104 chemical sciences ,Adduct ,Water/chemistry ,Hybrid system ,Photocatalysis ,Nanomedicine ,General Materials Science ,Materials Science (all) ,AFM ,0210 nano-technology ,Spin Trapping - Abstract
open 16 si Hybrid systems have great potential for a wide range of applications in chemistry, physics and materials science. Conjugation of a biosystem to a molecular material can tune the properties of the components or give rise to new properties. As a workhorse, here we take a C60@lysozyme hybrid. We show that lysozyme recognizes and disperses fullerene in water. AFM, cryo-TEM and high resolution X-ray powder diffraction show that the C60dispersion is monomolecular. The adduct is biocompatible, stable in physiological and technologically-relevant environments, and easy to store. Hybridization with lysozyme preserves the electrochemical properties of C60. EPR spin-trapping experiments show that the C60@lysozyme hybrid produces ROS following both type I and type II mechanisms. Due to the shielding effect of proteins, the adduct generates significant amounts of1O2also in aqueous solution. In the case of type I mechanism, the protein residues provide electrons and the hybrid does not require addition of external electron donors. The preparation process and the properties of C60@lysozyme are general and can be expected to be similar to other C60@protein systems. It is envisaged that the properties of the C60@protein hybrids will pave the way for a host of applications in nanomedicine, nanotechnology, and photocatalysis. embargoed_20190601 Matteo Di Giosia, Paul H. H. Bomans, Andrea Bottoni, Andrea Cantelli, Giuseppe Falini, Paola Franchi, Giuseppe Guarracino, Heiner Friedrich, Marco Lucarini, Francesco Paolucci, Stefania Rapino, Nico A. J. M. Sommerdijk, Alice Soldà, Francesco Valle, Francesco Zerbetto, Matteo Calvaresi Matteo Di Giosia, Paul H. H. Bomans, Andrea Bottoni, Andrea Cantelli, Giuseppe Falini, Paola Franchi, Giuseppe Guarracino, Heiner Friedrich, Marco Lucarini, Francesco Paolucci, Stefania Rapino, Nico A. J. M. Sommerdijk, Alice Soldà, Francesco Valle, Francesco Zerbetto, Matteo Calvaresi
- Published
- 2018
34. Single-molecule mechanics of synthetic aromatic amide helices: Ultrafast and robust non-dissipative winding
- Author
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Xuesong Li, Victor Maurizot, Anne-Sophie Duwez, Francesco Zerbetto, Ivan Huc, Floriane Devaux, Evangelos Bakalis, Damien Sluysmans, Chimie et Biologie des Membranes et des Nanoobjets (CBMN), Université de Bordeaux (UB)-École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), European Project: 320892,EC:FP7:ERC,ERC-2012-ADG_20120216,A2F2(2013), European Project: IDS-FunMat, École Nationale d'Ingénieurs des Travaux Agricoles - Bordeaux (ENITAB)-Institut de Chimie du CNRS (INC)-Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Devaux F., Li X., Sluysmans D., Maurizot V., Bakalis E., Zerbetto F., Huc I., and Duwez A.-S.
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Materials science ,General Chemical Engineering ,02 engineering and technology ,helical folding ,010402 general chemistry ,01 natural sciences ,Biochemistry ,SDG9: Industry, innovation, and infrastructure ,molecular machines with tailored propertie ,reversible processes ,foldamer ,Materials Chemistry ,Environmental Chemistry ,Molecule ,foldamers ,Elasticity (economics) ,Mechanical energy ,AFM force spectroscopy ,single-molecule mechanics ,Biochemistry (medical) ,Force spectroscopy ,molecular machines with tailored properties ,General Chemistry ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,reversible processe ,0104 chemical sciences ,Folding (chemistry) ,Chemical physics ,Dissipative system ,Protein folding ,elasticity ,0210 nano-technology ,Ultrashort pulse - Abstract
Summary Because of proteins’ many degrees of conformational freedom, programming protein folding dynamics, overall elasticity, and motor functions remains an elusive objective. Instead, smaller and simpler objects, such as synthetic foldamers, may be amenable to design. However, little is known about their mechanical performance. Here, we show that reducing molecular size may not compromise mechanical properties. We report that helical aromatic oligoamides as small as 1 nm possess outstanding elasticity and outperform most natural helices. Using single-molecule force spectroscopy, we characterize their folding trajectories and intermediate states. We show that they cooperatively and reversibly unwind at high forces. They extend up to 3.8 times their original length and rewind against considerable forces on a timescale of 10 μs. Pulling and relaxing cycles follow the same trace up to a very high loading rate, indicating that the mechanical energy accumulated during the stretching does not dissipate and is immediately reusable.
- Published
- 2021
35. Identification and preparation of stable water dispersions of protein - Carbon nanotube hybrids and efficient design of new functional materials
- Author
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Elisa Fasoli, Andrea Cantelli, Andrea Bottoni, Matteo Calvaresi, Matteo Di Giosia, Francesco Valle, Francesco Zerbetto, Di Giosia M., Valle F., Cantelli A., Bottoni A., Zerbetto F., Fasoli E., and Calvaresi M.
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Virtual screening ,Materials science ,High selectivity ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Water soluble ,chemistry ,law ,Molecule ,nanotube, docking, protein ,General Materials Science ,0210 nano-technology ,Carbon ,Electronic properties - Abstract
Carbon nanotubes, CNTs, and proteins could not be more chemically and physically distant. CNTs are hardly soluble and strongly hydrophobic. They are smooth wires, mechanically strong, with electronic properties that make them unique. Many proteins are water soluble and hydrophilic. They are highly corrugated and elastic. They can recognize a target molecule with high selectivity and sensitivity and can have catalytic activity. Integration of the remarkably different features of CNTs and proteins would create a new class of multifunctional materials. The conundrum to solve lies in how to best match proteins and CNTs. High-throughput virtual screening is used to predict the ability of 1207 proteins to recognize carbon tubes with a well-defined 1.3 nm diameter. The propensity for formation of protein-CNT hybrids is ranked. Experiments carried out in this work validated the computational results and show that the identified proteins are able to bind and disperse in water the selected CNTs. The highest scoring proteins are further examined in detail to identify general rules for binding and discussed for a variety of practical applications.
- Published
- 2019
36. Effects of knot tightness at the molecular level
- Author
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Francesco Zerbetto, Angela Acocella, Liang Zhang, Jean-François Lemonnier, Matteo Calvaresi, David A. Leigh, Zhang L., Lemonnier J.-F., Acocella A., Calvaresi M., Zerbetto F., and Leigh D.A.
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Circular dichroism ,Multidisciplinary ,Chemistry ,Chemical topology ,Supramolecular chemistry ,02 engineering and technology ,Molecular knot ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Mathematics::Geometric Topology ,01 natural sciences ,Dissociation (chemistry) ,0104 chemical sciences ,Molecular dynamics ,Knot (unit) ,Chemical physics ,Covalent bond ,Physical Sciences ,Proton NMR ,0210 nano-technology ,Spectroscopy - Abstract
Three 819 knots in closed-loop strands of different lengths (approximately 20, 23 and 26 nm) were used to experimentally assess the consequences of knot tightness at the molecular level. Through the use of 1H nuclear magnetic resonance (NMR), diffusion ordered spectroscopy (DOSY), circular dichroism (CD), collision induced dissociation mass spectrometry (CID-MS) and molecular dynamics (MD) simulations on the different sized knots, we find that the structure, dynamics and reactivity of the molecular chains are dramatically affected by the tightness of the knotting. The tautness of entanglement causes differences in conformation, enhances the expression of topological chirality, weakens covalent bonds, inhibits decomplexation events and changes absorption properties. Understanding the effects of tightening nanoscale knots may usefully inform the design of knotted and entangled molecular materials.
- Published
- 2019
37. CNT‐Catalyzed Oxidative Dehydrogenation of Ethylbenzene to Styrene: DFT Calculations Disclose the Pathways
- Author
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Andrea Bottoni, Francesco Zerbetto, Tainah Dorina Marforio, Matteo Calvaresi, Marforio T.D., Bottoni A., Zerbetto F., and Calvaresi M.
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Renewable Energy, Sustainability and the Environment ,DFT computation ,Energy Engineering and Power Technology ,Oxidative phosphorylation ,Carbon nanotube ,Photochemistry ,Ethylbenzene ,Catalysis ,law.invention ,Styrene ,ethylbenzene ,Biomaterials ,nano-carbon catalysi ,oxidative dehydrogenation ,chemistry.chemical_compound ,chemistry ,law ,styrene ,Materials Chemistry ,Dehydrogenation ,carbon nanotube - Abstract
Oxygen atoms, in the form of epoxy or carbonyl groups present at the edges of carbon nanotubes, trigger oxidative dehydrogenation of ethylbenzene to styrene. DFT calculations reveal that the process can occur along three pathways. The first two bifurcate from the initial transformation of an epoxide into a hydroxyl group, which occurs via a biradical transition state and the formation of a benzyl-like intermediate. The epoxide can further react to release styrene and form a water molecule, as observed experimentally, via a highly exothermic process. Alternatively, in the presence of a second adjacent epoxide, styrene is also produced without water formation along a less exothermic pathway that leaves two hydroxyl groups on the nanotube surface. Along the third pathway, two adjacent carbonyl groups (quinone functionality) also promote the formation of styrene, with energy barriers similar to those calculated in the presence of epoxy groups. These are in the range 36–37 kcal mol −1 . These values that can be easily surmounted at the working temperature used in the experiment (between 450 and 550 °C).
- Published
- 2019
38. An ‘imperial radiation’: Experimental and theoretical investigations of the photo-induced luminescence properties of 6,6′-dibromoindigo (Tyrian purple)
- Author
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David Saunders, Daniela Comelli, Austin Nevin, Charlotte Martin de Fonjaudran, Gianluca Accorsi, Angela Acocella, Francesco Zerbetto, Giovanni Verri, Cosimo D'Andrea, Verri, Giovanni, de Fonjaudran, Charlotte Martin, Acocella, Angela, Accorsi, Gianluca, Comelli, Daniela, D'Andrea, Cosimo, Nevin, Austin, Zerbetto, Francesco, and Saunders, David
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Materials science ,Infrared ,Process Chemistry and Technology ,General Chemical Engineering ,Analytical chemistry ,02 engineering and technology ,Radiation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Picosecond ,Chemical Engineering (all) ,Density functional theory ,0210 nano-technology ,Luminescence ,Absorption (electromagnetic radiation) - Abstract
6,6′-dibromoindigo (DBI) is the main component of Tyrian purple, or Imperial purple, one of the most controversial, sought-after and expensive colouring matters of antiquity. Evidence of its use, both as a pigment and as a dye, is found in the archaeological record, especially in the countries surrounding the Mediterranean basin. The photo-induced luminescence properties of a synthetic sample of DBI were studied in this paper. Time-Dependent Density Functional theory (TD-DFT) was used to predict and rationalise the optical absorption and emission properties of DBI in DMSO and compared with the experimental data. The emission properties of the solid-state sample were characterised for the first time. DBI shows an emission maximum in the infrared range, at about 870 nm, and lifetime in the picosecond range. The spatial distribution of the photo-induced luminescence emission could also be recorded using a commercial infrared-sensitive camera, opening up the possibility of non-invasively investigating the use of DBI on historical artefacts.
- Published
- 2019
39. Multifractal structure of microscopic eye–head coordination
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Yasuto Tanaka, Hiroyuki Fujie, Evangelos Bakalis, Francesco Zerbetto, Bakalis, Evangelo, Fujie, Hiroyuki, Zerbetto, Francesco, and Tanaka, Yasuto
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Statistics and Probability ,genetic structures ,Computer science ,Head (linguistics) ,business.industry ,eye–head coordination ,Decoherence ,Multifractal system ,Multifractal ,Condensed Matter Physics ,01 natural sciences ,Visual processing ,Fixational eye movements ,03 medical and health sciences ,0302 clinical medicine ,0103 physical sciences ,Computer vision ,Artificial intelligence ,Microsaccade ,010306 general physics ,business ,030217 neurology & neurosurgery - Abstract
Fixational eye movements contribute to visual processing. The information encoded in them is crucial for signals coming from fovea since it connects visual information with brain activity. We recorded microsaccades and tiny head movements at high resolution, with a sampling rate of 300 Hz. Microsaccades are likely influenced by heads’s motion. Multifractal analysis shows that both movements are multiplicative processes of different origins, thereby reflecting the presence of different strategies. Microsaccades draw steps from a broad distribution of probability values, which likely indicates the way that the eyes use to maximize information, and satisfies a stretched exponential distribution. On the other hand, tiny head movements are described well by a lognormal distribution. Both movements, eye and head, are initially correlated and de-coherence of the two takes place for times greater than 29.2 seconds.
- Published
- 2018
40. Human Serum Albumin-Oligothiophene Bioconjugate: A Phototheranostic Platform for Localized Killing of Cancer Cells by Precise Light Activation
- Author
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Marco Malferrari, Andrea Cantelli, Giorgia Simonetti, Matteo Di Giosia, Matteo Calvaresi, Mattia Zangoli, Francesco Zerbetto, Edoardo Toscanella, Sonny Forni, Giovanna Barbarella, Edoardo Jun Mattioli, Francesca Di Maria, Alberto Zanelli, Alice Soldà, Stefania Rapino, Cantelli, A, Malferrari, M, Solda, A, Simonetti, G, Forni, S, Toscanella, E, Mattioli, EJ, Zerbetto, F, Zanelli, A, Di Giosia, M, Zangoli, M, Barbarella, G, Rapino, S, Di Maria, F, and Calvaresi, M
- Subjects
Circular dichroism ,Biocompatibility ,oligothiophenes ,medicine.medical_treatment ,Photodynamic therapy ,Article ,oligothiophene ,medicine ,bioconjugate ,QD1-999 ,reactive oxygen species ,reactive oxygen specie ,Bioconjugation ,photostimulated apoptosi ,phototheranostics ,Chemistry ,phototheranostic ,Human serum albumin ,Fluorescence ,photodynamic therapy ,human serum albumin ,photostimulated apoptosis ,Cancer cell ,Biophysics ,Phototoxicity ,medicine.drug - Abstract
The electronic, optical, and redox properties of thiophene-based materials have made them pivotal in nanoscience and nanotechnology. However, the exploitation of oligothiophenes in photodynamic therapy is hindered by their intrinsic hydrophobicity that lowers their biocompatibility and availability in water environments. Here, we developed human serum albumin (HSA)–oligothiophene bioconjugates that afford the use of insoluble oligothiophenes in physiological environments. UV–vis and electrophoresis proved the conjugation of the oligothiophene sensitizers to the protein. The bioconjugate is water-soluble and biocompatible, does not have any “dark toxicity”, and preserves HSA in the physiological monomeric form, as confirmed by dynamic light scattering and circular dichroism measurements. In contrast, upon irradiation with ultralow light doses, the bioconjugate efficiently produces reactive oxygen species (ROS) and leads to the complete eradication of cancer cells. Real-time monitoring of the photokilling activity of the HSA–oligothiophene bioconjugate shows that living cells “explode” upon irradiation. Photodependent and dose-dependent apoptosis is one of the primary mechanisms of cell death activated by bioconjugate irradiation. The bioconjugate is a novel theranostic platform able to generate ROS intracellularly and provide imaging through the fluorescence of the oligothiophene. It is also a real-time self-reporting system able to monitor the apoptotic process. The induced phototoxicity is strongly confined to the irradiated region, showing localized killing of cancer cells by precise light activation of the bioconjugate.
- Published
- 2021
41. Green Fabrication of (6,5)Carbon Nanotube/Protein Transistor Endowed with Specific Recognition
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Gian Carlo Gazzadi, Martina Giordani, Matteo Di Giosia, Francesco Zerbetto, Marcello Berto, Matteo Calvaresi, Andrea Cantelli, Claudia Menozzi, Carlo Augusto Bortolotti, Fabio Biscarini, Matteo Sensi, Andrea Alessandrini, Francesco Valle, Berto M., Di Giosia M., Giordani M., Sensi M., Valle F., Alessandrini A., Menozzi C., Cantelli A., Gazzadi G.C., Zerbetto F., Calvaresi M., Biscarini F., and Bortolotti C.A.
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Green chemistry ,Fabrication ,Materials science ,carbon nanotubes ,green chemistry ,Transistor ,biosensors ,electrolyte-gated transistors ,lysozymes ,Nanotechnology ,02 engineering and technology ,Carbon nanotube ,biosensor ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,electrolyte-gated transistor ,law ,carbon nanotube ,0210 nano-technology ,Biosensor - Abstract
A general single-step approach is introduced for the green fabrication of hybrid biosensors from water dispersion. The resulting device integrates the semiconducting properties of a carbon nanotube (CNT) and the functionality of a protein. In the initial aqueous phase, the protein (viz., lysozyme [LZ]) disperses the (6,5)CNT. Drop-casting of the dispersion on a test pattern (a silicon wafer with interdigitated Au source and drain electrodes) yields a fully operating, robust, electrolyte-gated transistor (EGT) in one step. The EGT response to biorecognition is then assessed using the LZ inhibitorN-acetyl glucosamine trisaccharide. Analysis of the output signal allows one to extract a protein-substrate binding constant in line with values reported for the free (without CNT) system. The methodology is robust, easy to optimize, redirectable toward different targets and sets the grounds for a new class of CNT-protein biosensors that overcome many limitations of the technology of fabrication of CNT biosensors
- Published
- 2021
42. Neuromorphic organic devices that specifically discriminate dopamine from Its metabolites by nonspecific interactions
- Author
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Martina Giordani, Luciano Fadiga, Carlo Augusto Bortolotti, Michele Zoli, Marcello Berto, Matteo Sensi, Francesco Zerbetto, Michele Di Lauro, Fabio Biscarini, Henrique L. Gomes, Giordani, Martina, Sensi, Matteo, Berto, Marcello, Di Lauro, Michele, Bortolotti, Carlo Augusto, Gomes, Henrique Leonel, Zoli, Michele, Zerbetto, Francesco, Fadiga, Luciano, and Biscarini, Fabio
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Materials science ,Organic devices ,Socio-culturale ,Nanotechnology ,biosensors, neuromorphic devices, organic bioelectronics, PEDOT:PSS, short-term plasticity ,Biomaterials ,PEDOT:PSS ,Dopamine ,Electrochemistry ,medicine ,neuromorphic devices ,Organic bioelectronics ,Sensors - organic electronics ,PEDOT ,organic bioelectronics ,PSS ,biosensors ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Biosensors ,Neuromorphic engineering ,Neuromorphic devices ,short-term plasticity [biosensors ,PEDOT] ,short-term plasticity ,Biosensor ,Short-term plasticity ,medicine.drug - Abstract
Specific detection of dopamine (DA) is achieved with organic neuromorphic devices with no specific recognition function in an electrolyte solution. The response to voltage pulses consists of amplitude-depressed current spiking mimicking the short-term plasticity (STP) of synapses. An equivalent circuit hints that the STP timescale of the device arises from the capacitance and resistance of the poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) in series with the electrolyte resistance. Both the capacitance and resistance of PEDOT:PSS change with solution compositions. Dose curves are constructed from the STP timescale for each DA metabolite from pM to mM range of concentrations. The STP response of DA is distinctive from the other metabolites even when differences are by one functional group. Both STP and sensitivity to DA are larger across the patho-physiological range with respect to those to DA metabolites. Density functional theory calculations hint to a stronger hydrogen bond pattern of DA ammonium compared to cationic metabolites. The exponential correlation between STP and the binding energy of DA metabolites interacting with PEDOT:PSS indicates that the slow dynamics of ionic species in and out PEDOT:PSS is the origin of the neuromorphic STP. The sensing framework discriminates differences of nonspecific interactions of few kcal mol(-1), corresponding to one functional group in the molecule. Life Science Department Biomedical, Metabolic and Neural Sciences Department of University of Modena and Reggio Emilia through "FAR 2018" Dipartimenti di eccellenza 2018-2022, MIUR, Italy Regione Emilia-Romagna through "Percorso co-finanziato con risorse del Fondo Sociale Europeo Programma Operativo 2014/2020" Biomedical, Metabolic and Neural Sciences Department of University of Modena and Reggio Emilia through "FAR 2015" info:eu-repo/semantics/publishedVersion
- Published
- 2020
43. Interactions between Endohedral Metallofullerenes and Proteins: The Gd@C60–Lysozyme Model
- Author
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Francesco Zerbetto, Edoardo Jun Mattioli, Andrea Bottoni, Fabio Bologna, Matteo Calvaresi, Bologna, Fabio, Mattioli, Edoardo Jun, Bottoni, Andrea, Zerbetto, Francesco, and Calvaresi, Matteo
- Subjects
animal structures ,medicine.diagnostic_test ,General Chemical Engineering ,Chemistry (all) ,Magnetic resonance imaging ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Article ,0104 chemical sciences ,lcsh:Chemistry ,chemistry.chemical_compound ,Nuclear magnetic resonance ,chemistry ,lcsh:QD1-999 ,medicine ,Chemical Engineering (all) ,Lysozyme ,0210 nano-technology - Abstract
Endohedral metallofullerenes (EMFs) have great potential as radioisotope carriers for nuclear medicine and as contrast agents for X-ray and magnetic resonance imaging. EMFs have still important restrictions for their use due to low solubility in physiological environments, low biocompatibility, nonspecific cellular uptake, and a strong dependence of their peculiar properties on physiological parameters, such as pH and salt content. Conjugation of the EMFs with proteins can overcome many of these limitations. Here we investigated the thermodynamics of binding of a model EMF (Gd@C60) with a protein (lysozyme) that is known to act as a host for the empty fullerene. As a rule, even if the shape of an EMF is exactly the same as that of the related fullerene, the interactions with a protein are significantly different. The estimated interaction energy (δGbinding) between Gd@C60 and lysozyme is -18.7 kcal mol-1, suggesting the possibility of using proteins as supramolecular carriers for EMFs. π-π stacking, hydrophobic interactions, surfactant-like interactions, and electrostatic interactions govern the formation of the hybrid between Gd@C60 and lysozyme. The comparison of the energy contributions to the binding between C60 or Gd@C60 and lysozyme suggests that, although shape complementarity remains the driving force of the binding, the presence of electron transfer from the gadolinium atom to the carbon cage induces a charge distribution on the fullerene cage that strongly affects its interaction with the protein.
- Published
- 2018
44. RETRACTED: Photophysics of artist’s pigments
- Author
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David Saunders, Gianluca Accorsi, Giovanni Verri, Diego Tamburini, Samuel Whittaker, Amarilli Rava, Francesco Zerbetto, Angela Acocella, and Charlotte Martin de Fonjaudran
- Subjects
Applied Mathematics ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Instrumentation - Published
- 2018
45. Aromatic Bromination of N-Phenylacetamide Inside CNTs. Are CNTs Real Nanoreactors Controlling Regioselectivity and Kinetics? A QM/MM Investigation
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Tainah Dorina Marforio, Andrea Bottoni, Pietro Giacinto, Francesco Zerbetto, Matteo Calvaresi, Marforio, Tainah Dorina, Bottoni, Andrea, Giacinto, Pietro, Zerbetto, Francesco, and Calvaresi, Matteo
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Steric effects ,Electronic, Optical and Magnetic Material ,Regioselectivity ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Ethylbenzene ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Catalysis ,QM/MM ,Solvent ,chemistry.chemical_compound ,Energy (all) ,General Energy ,chemistry ,Arenium ion ,Physical and Theoretical Chemistry ,0210 nano-technology ,Protic solvent - Abstract
We carried out a computational investigation on the mechanism of the bromination reaction of N-phenylacetamide inside CNTs, in water, and in an aprotic solvent (ethylbenzene). A full QM and a QM/MM approach was used. In the aprotic solvent, a Wheland intermediate (ion pair formed by arenium ion and chloride) exists only for the attack in the ortho position, while the para attack proceeds in a concerted manner (concerted direct substitution). The reaction is catalyzed by the HCl byproduct, which lowers significantly the activation barriers. The ortho product is favored, in contrast to the common belief based on simple steric effects. In water solution a Wheland intermediate was located for both ortho and para attacks (the ion pair is stabilized by the polar protic solvent). The formation of the para product is favored with respect to the ortho product: 9.0 and 9.9 kcal mol-1are the corresponding activation barriers. Inside CNTs, as found in aprotic solvent, the Wheland-type arenium ion exists only along the ortho pathway. The initial production of the HCl byproduct activates rapidly the catalyzed mechanism that proceeds almost exclusively along the para pathway (para and ortho activation barriers are 6.1 and 17.0 kcal mol-1, respectively). The almost exclusive para regioselectivity for the CNT-confined reaction and its acceleration with respect to water (in agreement with the experimental evidence) are due to noncovalent (van der Waals) interactions between the endohedral system and the electron cloud of the surrounding CNT. The effect of these interactions was estimated quantitatively within the UFF scheme used in our QM/MM computations, and we found that they are particularly stabilizing for the para-catalyzed process.
- Published
- 2017
46. C60 Bioconjugation with Proteins: Towards a Palette of Carriers for All pH Ranges
- Author
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Francesco Valle, Matteo Di Giosia, Andrea Cantelli, Matteo Calvaresi, Andrea Bottoni, Francesco Zerbetto, and Matteo Di Giosia, Francesco Valle, Andrea Cantelli, Andrea Bottoni, Francesco Zerbetto, Matteo Calvaresi
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Fullerene ,bioconjugation ,Ionic bonding ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,nanobiotechnology ,01 natural sciences ,chemical stability ,Nanobiotechnology ,General Materials Science ,Aqueous solution ,Bioconjugation ,nanotechnology ,Chemistry ,fullerenes ,021001 nanoscience & nanotechnology ,nanohybrids ,0104 chemical sciences ,Nanohybrid ,Nanomedicine ,Chemical stability ,Materials Science (all) ,0210 nano-technology ,Dispersion (chemistry) - Abstract
The high hydrophobicity of fullerenes and the resulting formation of aggregates in aqueous solutions hamper the possibility of their exploitation in many technological applications. Noncovalent bioconjugation of fullerenes with proteins is an emerging approach for their dispersion in aqueous media. Contrary to covalent functionalization, bioconjugation preserves the physicochemical properties of the carbon nanostructure. The unique photophysical and photochemical properties of fullerenes are then fully accessible for applications in nanomedicine, sensoristic, biocatalysis and materials science fields. However, proteins are not universal carriers. Their stability depends on the biological conditions for which they have evolved. Here we present two model systems based on pepsin and trypsin. These proteins have opposite net charge at physiological pH. They recognize and disperse C60 in water. UV-Vis spectroscopy, zeta-potential and atomic force microscopy analysis demonstrates that the hybrids are well dispersed and stable in a wide range of pH’s and ionic strengths. A previously validated modelling approach identifies the protein-binding pocket involved in the interaction with C60. Computational predictions, combined with experimental investigations, provide powerful tools to design tailor-made C60@proteins bioconjugates for specific applications.
- Published
- 2018
47. Graphene Materials Strengthen Aqueous Polyurethane Adhesives
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Marco Montalti, Gloria Guidetti, Matteo Calvaresi, Marco Gibertini, Francesco Zerbetto, Luca Cristofolini, Giuseppe Falini, Kavin Morellato, and Luca Cristofolini, Gloria Guidetti, Kavin Morellato, Marco Gibertini, Matteo Calvaresi, Francesco Zerbetto, Marco Montalti, Giuseppe Falini
- Subjects
Aqueous solution ,Materials science ,Scanning electron microscope ,Graphene ,General Chemical Engineering ,graphene, polyurethane, adhesive ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Article ,0104 chemical sciences ,law.invention ,Polyester ,chemistry.chemical_compound ,Thermoplastic polyurethane ,chemistry ,law ,Adhesive ,Composite material ,0210 nano-technology ,Thermal analysis ,Polyurethane - Abstract
Carboxyl-functionalized graphene platelets (GP) and graphene oxide (GO) sheets were added to a commercial aqueous adhesive dispersion of thermoplastic polyurethane (TP) (Idrotex 200 from FacGB s.r.l.). For both additives, the weight percentage was of industrial interest, 0.01 and 10.1 wt %. The addition of GP/GO was carried out in a simple and scalable-up process that can be applied to other materials and additives. Mechanical, peel tests were applied on polyurethane strips (75 mm long, IS mm wide, and 1.5 mm thick) prepared cutting extruded sheets obtained using Estane 58091, a 70D aromatic polyester-based TP. The tests with 0.01 wt % of GP showed statistically significant higher forces at first failure and maximum forces with respect to the pristine adhesive. Sample characterization was carried out with scanning electron microscopy, infrared spectroscopy, X-ray diffraction, and thermal analysis. A mechanism is suggested for the improved performance of the low-dose GP adhesive.
- Published
- 2018
48. C60@lysozyme: a new photosensitizing agent for photodynamic therapy
- Author
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Matteo Calvaresi, Stefania Rapino, Marco Montalti, Alice Soldà, Andrea Cantelli, Francesco Zerbetto, M. Di Giosia, Soldã , A., Cantelli, A., Di Giosia, M., Montalti, M., Zerbetto, F., Rapino, S., and Calvaresi, M.
- Subjects
medicine.medical_treatment ,Biomedical Engineering ,Photodynamic therapy ,02 engineering and technology ,010402 general chemistry ,Photochemistry ,01 natural sciences ,HeLa ,chemistry.chemical_compound ,medicine ,General Materials Science ,Viability assay ,Irradiation ,Hydrogen peroxide ,chemistry.chemical_classification ,Reactive oxygen species ,biology ,Singlet oxygen ,Medicine (all) ,Chemistry (all) ,General Chemistry ,General Medicine ,Photosensitizing Agent ,021001 nanoscience & nanotechnology ,biology.organism_classification ,0104 chemical sciences ,chemistry ,Materials Science (all) ,0210 nano-technology - Abstract
C60@lysozyme showed significant visible light-induced singlet oxygen generation in water, indicating the potential of this hybrid as an agent for photodynamic therapy. The reactive oxygen species (ROS) concentration generated by C60@lysozyme during irradiation depends on the light source, the irradiation time and the concentration of the hybrid. C60@lysozyme significantly reduced the HeLa cell viability in response to visible light irradiation. The generation of H2O2, due to the photoactivity of C60@lysozyme, causes cell death via easy permeation of hydrogen peroxide through the cell membrane and activation of endogenous ROS production.
- Published
- 2017
49. Analysis of the vibronic structure of the trans-stilbene fluorescence and excitation spectra: the S0 and S1 PES along the CeCe and Ce–Cph torsions
- Author
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Giorgio Orlandi, Marco Garavelli, Francesco Zerbetto, Orlandi, Giorgio, Garavelli, Marco, and Zerbetto, Francesco
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010304 chemical physics ,Chemistry ,Anharmonicity ,General Physics and Astronomy ,Torsion (mechanics) ,010402 general chemistry ,01 natural sciences ,Bond order ,Fluorescence ,Spectral line ,0104 chemical sciences ,Physics and Astronomy (all) ,0103 physical sciences ,Potential energy surface ,Physical and Theoretical Chemistry ,Atomic physics ,Excitation ,Eigenvalues and eigenvectors - Abstract
We analyze the highly resolved vibronic structure of the low energy (â¤200 cm-1) region of the fluorescence and fluorescence excitation spectra of trans-stilbene in supersonic beams. In this spectral region the vibronic structure is associated mainly with vibrational levels of the Ce-Ce torsion (Ï) and the au combination of the two Ce-Cph bond twisting (Ï). We base this analysis on the well-established S0(Ï, Ï) two-dimensional potential energy surface (PES) and on a newly refined S1(Ï, Ï) PES. We obtain vibrational eigenvalues and eigenvectors of the anharmonic S0(Ï, Ï) and S1(Ï, Ï) PES using a numerical procedure based on the Meyer's flexible model [R. Meyer, J. Mol. Spectrosc., 1979, 76, 266]. Then we derive Franck-Condon factors and therefore intensities of the relevant vibronic bands for the S0 â S1 excitation and S1 â S0 fluorescence spectra. Furthermore, we assess the role of the bg combination of the two Ce-Cph bond twisting (ν48) in the structure of the S1 â S0 fluorescence spectra. By the use of these results we are able to assign most of the low energy vibrational levels of the S0 â S1 excitation spectra and of the fluorescence spectra of the emission from several low energy S1 vibronic levels. The good agreement between the observed and the computed vibrational structure of the S0 â S1 and S1 â S0 spectra suggests that the proposed picture of the E1(Ï, Ï) and E0(Ï, Ï) PES, in particular along the coordinate Ï governing trans-cis photo-isomerization in S1, is accurate. In S0, the barriers for the CeCe torsion and for the au type Ce-Cph bond twisting are 16:080 cm-1 and 3125 cm-1, respectively, while in S1, where the bond orders of the CeCe and Ce-Cph bonds are reversed, the two barriers become 1350 cm-1 and 8780 cm-1, respectively.
- Published
- 2017
50. Photocatalytic activity of exfoliated graphite-TiO
- Author
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Gloria, Guidetti, Eva A A, Pogna, Lucia, Lombardi, Flavia, Tomarchio, Iryna, Polishchuk, Rick R M, Joosten, Alessandro, Ianiro, Giancarlo, Soavi, Nico A J M, Sommerdijk, Heiner, Friedrich, Boaz, Pokroy, Anna K, Ott, Marco, Goisis, Francesco, Zerbetto, Giuseppe, Falini, Matteo, Calvaresi, Andrea C, Ferrari, Giulio, Cerullo, and Marco, Montalti
- Abstract
We investigate the photocatalytic performance of composites prepared in a one-step process by liquid-phase exfoliation of graphite in the presence of TiO
- Published
- 2019
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