1,720,964 research outputs found
Formulazione di siRNA anti blimp-1/PRDM in liposomi cationici: caratterizzazione chimico-fisica e validazione in vitro su cellule di LINFOMA EFFUSIVO PRIMARIO (pel)
No full textFormulazione di siRNA anti blimp-1/PRDM in liposomi cationici: caratterizzazione chimico-fisica e validazione in vitro su cellule di LINFOMA EFFUSIVO PRIMARIO (pel
Nanotechnology and Alzheimer’s disease: What has been done and what to do’
No full textUp to date, Alzheimer’s Disease (AD) is considered as an “urgency” for public health, since it represents one of the most dramatic causes of death in adults. The drugs currently used for AD are only symptomatic, thus not curing the pathology, but only trying to slow or delay the progression of the pathology. Moreover, there is a total lack of early identification, with only “probable’’ or ‘‘possible’’ diagnosis of AD patients. With this review, we aimed to individuate and to highlight the most promising approaches for AD therapy and diagnosis. In this view, at the cutting-edge of innovation, nanocarriers as polymeric nanoparticles, liposomes, nanoassembly and dendrimers, have been studied and investigated in order to ameliorate the detection (in vitro and in vivo) and/or the therapeutic options in AD. In this review, the most outstanding nanomedicine-driven approaches in AD imaging/detection and treatments are summarized in order to help in individuating values and criticisms. Moreover, an overview of one of the most innovative strategies in AD management, namely theranostic nanomedicine, is reported and commented
NANOPARTICELLE IBRIDE PLGA/DOPE: STUDI DI TRANSFEZIONE, ESCAPE ENDOSOMIALE E TRAFFICKING CELLULARE
No full textStudi in vivo e in vitro hanno dimostrato che nanoparticelle (Nps) di PLGA (co-polimero tra acido lattico e acido glicolico), coniugate in superficie con il glicopeptide g7, sfruttano meccanismi di endocitosi clatrina dipendenti per attraversare la barriera emato encefalica (BEE) e per entrare in cellule neuronali e gliari (Tosi et al., Nanomedicine, 2011; Grabrucker et al., PloS One, 2011). Tali studi hanno anche evidenziato la difficoltà di questi vettori di evadere dal compartimento endolisosomiale, pregiudicando il rilascio di farmaci attivi a livello citoplasmatico e nucleare. In questo contesto, sono state formulate Nps ibride, miscelando il PLGA con il DOPE (dioleoilfosfatidiletanolamina), un lipide con caratteristiche fusogeniche, già impiegato per la formulazione di liposomi, applicati particolarmente in terapia genica.
Utilizzando la tecnica della doppia emulsione, sono state formulate Nps impiegando diverse quantità di DOPE (2.5, 5, 10 e 20% p/p rispetto al PLGA). Messa a punto la tecnica di purificazione dei campioni, per ogni tipologia è stato dosato il lipide effettivamente incorporato nella matrice ed ogni preparazione è stata caratterizzata dal punto di vista
dimensionale e di carica superficiale (potenziale Z). Studi di microscopia elettronica a scansione (SEM) e a forza atomica (AFM) hanno mostrato come varia la morfologia dei campioni al variare della loro composizione. I primi studi in vitro, in rapporto alla tossicità cellulare,hanno dimostrato la migliorata capacità di escape endosomiale di tali sistemi rispetto alle Nps polimeriche. In particolare, incoraggianti risultati sono stati osservati dopo transfezione con sistemi ibridi allestiti con basse concentrazioni di DOPE (5%), confermando le potenzialità di questa strategia nel targeting subcellulare di farmaci
AFM/TEM complementary structural analysis of surface-functionalized nanoparticles
Full text linkIn the field of nanomedicine, the characterization of functionalized drug delivery systems, introduced on market as efficacious and selective therapeutics, represents a pivotal aspect of great importance. In particular, the morphology of polymeric nanoparticles, the most studied nanocarriers, is frequently assessed by transmission electron microscopy (TEM). Despite of TEM high resolution and versatility, this technology is frequently hampered by both the complicated procedure for sample preparation and the operative condition of analysis. Considering the scanning probe microscopies, atomic force microscopy (AFM) represents an extraordinary tool for the detailed characterization of submicron-size structure as the surface functionalization at the atomic scale. In this paper we discussed the advantage and limits of these microscopies applied to the characterization of PLGA nanoparticles functionalized with three different kinds of ligands (carbohydrate ligand, an antibody and quantum dots crystals) intentionally designed, created and tailored with specific physico-chemical properties to meet the needs of specific applications (targeting or imaging)
Apoferritin nanocage as streptomycin drug reservoir: Technological optimization of a new drug delivery system
Full text linkThe aim of this study is to formulate and characterize streptomycin-loaded apoferritin nanoparticles (ApoStrep NPs) for their potential therapeutic use in bacterial resistant infections (i.e. tuberculosis). ApoStrep NPs were prepared by disassembly/reassembly process via pH method and changing apoferritin/drug molar ratio, purified by dialyses process also associated with gel filtration chromatography and characterized in their chemico-physical and technological parameters as yield, size distribution, polidispersivity, morphology, internal structure, zeta potential and loading efficacy. The results showed that spherical reproducible NPs could be obtained by using apoferritin/drug molar ratio lower than 1:25 and purification based on the combination of dialysis and gel filtration chromatography. Photon correlation spectroscopy, Uv–visible detection and electron microscopy showed the maintenance of the native apoferritin chemico-physical properties and structure. When formulated with apoferritin/drug 1:10 and 1:25 molar ratio, ApoStrep NPs showed remarkable encapsulation efficacy (35% and 28%, respectively) along with kinetic profile of drug delivery, approximately 15% at 37 °C in 72 h, as evidenced by “in vitro” release experiments
Leptin-conjugated nanoparticles as drug delivery system to the brain
No full textLeptin-conjugated nanoparticles as drug delivery system to the brai
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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