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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
Nanotechnology for the CNS drug delivery and targeting
No full textIn the last years, the application of "nanotechnology “to the field of “medicine” surely represented the most innovative strategy to cope with diseases and it coule be named as nanomedicine applied to difficult-to-treat diseases. As known, in this field of research, the most important goal to be reached is an increase in selectivity and specificity of drug action. Several results with stimulating findings in preclinical or clinical phases have been reached by using nanocarriers, delivering agents to targeted pathologies, and among them, it is known that neuro-pathologies represent a stimulating issue. In fact, the pharmaceutical treatment of Central Nervous System (CNS) disorders is the second largest area of therapy, following cardiovascular diseases. Nowadays, non-invasive drug delivery systems for CNS are actively studied. The nano-technological approach consist of the use of nanosystems (colloidal carriers) which could be polymer-based (nanoparticles, Np) or solid lipid material made (solid lipid nanoparticles, SLNp) and lipid-based (liposomes, LP). In fact, the development of these new delivery systems started with the discovery that properly surface-engineered colloidal vectors, with a diameter around 200 nm, were shown to be able to cross the BBB without apparent damage, and to deliver drugs or genetic materials into the brain. During this talk, an overview will be presented considering the most recent literature results of nanomedicine applied to brain diseases, carried out with all the most popular kinds of nanoparticulate systems, focusing in particular on peptide-decorated nanosystems able to target the CNS
Nanotech approaches to CNS delivery: nanoparticle surface modification to obtain long-circulating polymeric drug carriers
No full textThere is a broad interest in the development of nanoparticles (NPs) carrying on their surface carbohydrates such as sialic acids. It is known that these carbohydrates influence the biological and physical properties of biopharmaceutical proteins and living cells. Macromolecular compounds containing these carbohydrates showed an anti-recognition effect, exert an antiviral effect and also are able to be recognized by the cell surface of some kind of cancer cells. Thus, in the present research we performed two different approaches in order to obtain polymeric (poly(d,l-lactide-co-glycolide), PLGA) NPs surface decorated with the sialic acid N-acetylneuraminic acid (Neu5Ac). The first strategy that has been followed is based on the derivatization of the polyester PLGA with the thioderivative of Neu5Ac, starting material for the preparation of the NPs; the second is based on the synthesis of compounds potentially able to insert their lipophilic moiety into the underivatized PLGA NPs during their preparation, and to display their hydrophilic moiety (Neu5Ac) on their surface. The first approach allowed the obtainment of NPs surface decorated with Neu5Ac, as evidenced by ESCA spectroscopy and interaction with the lectin Wheat Germ Agglutinin. Moreover, a formulation of these NPs suitable for in vitro assays showed that they are phagocytosed by human monocytes with an apparently different mechanism with respect of those made of underivatized PLGA. The second strategy led to NPs in which their surface appears to be very different with respect to the NPs obtained following the first strategy, with the carboxylic groups of Neu5Ac markedly shielded. Thus, the new Neu5Ac-modified PLGA polyester represent a useful starting material for the preparation of NPs surface decorated with this sialic acid
CNS drug delivery by using polymeric nanoparticles
No full textSono state discusse le possibili modificazioni alla superficie di nanoparticelle per ottenere stabilità e possibilità di direzionamento al cervello
AFM phase imaging of soft-hydrated samples: A versatile tool to complete the chemical-physical study of liposomes
No full textDespite of the several approaches applied to the physicochemical characterization of liposomes, few techniques are really useful to obtain information about the surface properties of these colloidal drug-delivery systems. In this paper, we demonstrate a possible new application of tapping mode atomic force microscopy (AFM) to discriminate between conventional and pegylated liposomes. We showed that the differences on liposomal surface properties revealed by the phase images AFM approach well correlate with the data obtained using classical methods, such as light scattering, hydrodynamic, and nuclear magnetic resonance analysis
Sialic acid as surface modifier of polymeric PLGA nanoparticles
No full textNanoparticles for drug delivery to CN
Nanotech approaches to CNS delivery: nanoparticles surface modification to obtain long circulating polymeric drug carriers
No full textNanotech approaches to CNS delivery: nanoparticles surface modification to obtain long circulating polymeric drug carrier
Drug Delivery to the brain: in vivo evaluation on surface engeneered nanoparticles
No full textDrug Delivery to the brain: in vivo evaluation on surface engeneered nanoparticle
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