1,720,967 research outputs found
Covalent functionalization enables good dispersion and anisotropic orientation of multi-walled carbon nanotubes in a poly(l-lactic acid) electrospun nanofibrous matrix boosting neuronal differentiation
No full textA biocompatible porous scaffold obtained via electrospinning a nanocomposite solution of poly(l-lactic acid) and 4-methoxyphenyl functionalized multi-walled carbon nanotubes is presented here for the first time for the enhancement of neurite outgrowth. Optimization of blend preparation and deposition parameters paves the way to the obtainment of defect-free random networks of nanofibers with homogeneous diameters in the hundreds of nanometers length scale. The tailored covalent functionalization of nanotube surfaces allows a homogeneous dispersion of the nanofillers within the polymer matrix, diminishing their natural tendency to aggregate and form bundles. This results in a remarkable effect on the crystallization temperature, as evidenced through differential scanning calorimetry. Furthermore, transmission electron microscopy shows carbon nanotubes anisotropically aligned along the fiber axes, a feature believed to enhance neurite adhesion and growth. Indeed, microscopy images show neurites extension along the direction of nanofibers, highlighting the extreme relevance of scaffold morphology in engineering complex tissue environments. Furthermore, a remarkable effect on increasing the neurite outgrowth results when using the fibrous scaffold containing dispersed carbon nanotubes in comparison with an analogous one made of only polymer, providing further evidence of the key role played by carbon nanostructures in inducing neuronal differentiation
Enhanced neuronal cell differentiation combining biomimetic peptides and a carbon nanotube-polymer scaffold
No full textCarbon nanotubes are attractive candidates for the development of scaffolds able to support neuronal growth and differentiation thanks to their ability to conduct electrical stimuli, to interface with cells and to mimic the neural environment. We developed a biocompatible composite scaffold, consisting of multi-walled carbon nanotubes dispersed in a poly-L-lactic acid matrix able to support growth and differentiation of human neuronal cells. Moreover, to mimic guidance cues from the neural environment, we also designed synthetic peptides, derived from L1 and LINGO1 proteins. Such peptides could positively modulate neuronal differentiation, which is synergistically improved by the combination of the nanocomposite scaffold and the peptides, thus suggesting a prototype for the development of implants for long-term neuronal growth and differentiation.
The study describes the design and preparation of nanocomposite scaffolds with multi-walled carbon nanotubes in a poly-L-lactic acid matrix. This compound used in combination with peptides leads to synergistic effects in supporting neuronal cell growth and differentiation
METODO DI SINTESI DI NANOTUBI DI CARBONIO FUNZIONALIZZATI PER CICLOADDIZIONE IN FLUSSO CONTINUO ED APPARATO PER LO STESSO
No full textCarbon Nanotubes-Polymer Electrospun Nanofibers as Biocompatible Scaffold for Neuronal Cells Differentiation
No full textNoncovalent Interaction between Single-Walled Carbon Nanotubes and Pyrene-Functionalized Gold Nanoparticles in Water-Soluble Nanohybrids
No full textThe combination of different nanostructures in a multifunctional nanostructured hybrid is expected to improve their functionalities and lead to synergistic effects. In these regards, carbon nanotubes and gold colloids are well-studied building blocks with unique optical and electronic properties, which could be combined in a variety of optoelectronic applications. In this framework, we herein present an innovative approach to the preparation of water-soluble nanohybrids by noncovalent interaction between single-walled carbon nanotubes (SWCNTs) and gold nanoparticles (AuNPs) cofunctionalized with pyrenyl and choline residues. To this aim, we developed a procedure based on consecutive centrifugation steps, which allows straightforward isolation of the conjugates in their water-soluble form. Each step of the process was monitored by TEM and by UV–vis–NIR absorption spectroscopy to characterize the obtained nanohybrids and to confirm that the interaction of the pyrene residues of the cofunctionalized AuNPs with the nanotube walls is the only one responsible for the formation of the water-soluble nanohybrids. Further investigations including Raman spectroscopy and photoluminescence mapping confirm that the interaction between the AuNPs and the SWCNTs is arguably noncovalent and thus assures that the emission in the NIR region by the nanotubes is preserved. Measurements of the quenching of the fluorescence of pyrene by carbon nanotubes provide the association constants for complex formation between the cofunctionalized AuNPs and SWCNTs. The results reported herein provide the basis to novel strategies for the preparation of water-soluble nanohybrids between AuNPs and SWCNTs based on noncovalent interactions
An insight into the functionalisation of carbon nanotubes by diazonium chemistry: Towards a controlled decoration
No full textThe derivatisation of materials including iron, gold, and carbon by addition of diazonium salts is a reliable process to tune their interfacial interaction with the surrounding media. In this regard, the functionalisation of carbon nanostructures by diazonium chemistry is a versatile strategy to obtain soluble nanomaterials with degrees of functionalisation among the highest ever reported. Starting from these premises we have studied the functionalisation of multi-walled carbon nanotubes by addition of the aryl diazonium salts generated in situ by treatment of 4-methoxyaniline with isopentylnitrite. Following a thorough purification and characterisation protocol (UV–vis, TGA, ATR-IR, cyclic voltammetry, AFM and other surface analytical techniques), we have investigated the key parameters to obtain both functionalised multi-walled carbon nanotubes, where the amount of functional groups anchored to the carbon surface is less than a monolayer, and superfunctionalised carbon nanotubes, with a carbon nanotube core and a multilayered aryl coating. The results outlined provide the basis for the design and controlled processing of novel decorated carbon nanostructures that would be useful for a number of technological applications
4th FUR4Sustain Happy Hour - Patrizio Salice (NOVAMONT) 2022
No full text<p>Talk by Patrizio Salice from NOVAMONT on "An overview on biopolymers and bioplastics"</p>
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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