Advances in Cancer Treatment: Role of Nanoparticles

This chapter is devoted to the advances in the field of nanoparticles-mediated cancer treatment. A special attention is devoted to the use of magnetite and silver nanoparticles. The synthesis and properties of Fe3O4 and Ag nanoparticles as contrast or antitumoral agents as monolith or component of more complex systems such as polymer matrix composite materials based on: polymers (chitosan, collagen, polyethylene glycol, polyacrylates, and polymethacrylates, polylactic acid, etc.) and various antitumoral agents (cytostatics, natural agents and even nanoparticles-magnetite, silver, or gold) are discussed. Special attention is paid for the benefits and risks of using silver and magnetite nanoparticles. In both cases, the discussion focuses on aspects related to diagnosis and treatment of cancer. The influence of size and shape [1-3] is important from the materials characteristics as well as from the biological points of view. The role of magnetite is also analyzed from the point of view of its influence on the delivery of different components of interests (antitumoral components, analgesics/anti-inflammatory agents, etc.). The potentiating effect of the nanoparticles over the cytostatics and natural components is highlighted

Der Weg zur Erinnerungin W. G. Sebalds Austerlitz

The following essay provides a look into the role of the unconscious in the protagonist’s process of remembering in W.G. Sebald’s novel, Austerlitz. It aims to show that objects and places can reveal more than the actual information to which they are a repository or the purpose they were designed to serve. Rather, they function as connectors to the hidden world of repressed experiences. Recurring with obstinacy in the protagonist’s path, such connectors both show the way and obscure the view toward that which makes the real end of the search, that which has been lost. Thus, they not only provide an Ariadne’s thread to the protagonist’s search for himself but also to the reader’s literary experience. Using some concepts drawn from psychoanalytical theory, this essay hopes to make a contribution toward enhancing that experience

Reduced‐Graphene‐Oxide‐Based Needle‐Type Field‐Effect Transistor for Dopamine Sensing

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A thermodynamic approach to designing structure-free combinatorial DNA word sets

An algorithm is presented for the generation of sets of non-interacting DNA sequences, employing existing thermodynamic models for the prediction of duplex stabilities and secondary structures. A DNA ‘word’ structure is employed in which individual DNA ‘words’ of a given length (e.g. 12mer and 16mer) may be concatenated into longer sequences (e.g. four tandem words and six tandem words). This approach, where multiple word variants are used at each tandem word position, allows very large sets of non-interacting DNA strands to be assembled from combinations of the individual words. Word sets were generated and their figures of merit are compared to sets as described previously in the literature (e.g. 4, 8, 12, 15 and 16mer). The predicted hybridization behavior was experimentally verified on selected members of the sets using standard UV hyperchromism measurements of duplex melting temperatures (T(m)s). Additional experimental validation was obtained by using the sequences in formulating and solving a small example of a DNA computing problem

NNDB: the nearest neighbor parameter database for predicting stability of nucleic acid secondary structure

The Nearest Neighbor Database (NNDB, http://rna.urmc.rochester.edu/NNDB) is a web-based resource for disseminating parameter sets for predicting nucleic acid secondary structure stabilities. For each set of parameters, the database includes the set of rules with descriptive text, sequence-dependent parameters in plain text and html, literature references to experiments and usage tutorials. The initial release covers parameters for predicting RNA folding free energy and enthalpy changes

McGenus: A Monte Carlo algorithm to predict RNA secondary structures with pseudoknots

We present McGenus, an algorithm to predict RNA secondary structures with pseudoknots. The method is based on a classification of RNA structures according to their topological genus. McGenus can treat sequences of up to 1000 bases and performs an advanced stochastic search of their minimum free energy structure allowing for non trivial pseudoknot topologies. Specifically, McGenus employs a multiple Markov chain scheme for minimizing a general scoring function which includes not only free energy contributions for pair stacking, loop penalties, etc. but also a phenomenological penalty for the genus of the pairing graph. The good performance of the stochastic search strategy was successfully validated against TT2NE which uses the same free energy parametrization and performs exhaustive or partially exhaustive structure search, albeit for much shorter sequences (up to 200 bases). Next, the method was applied to other RNA sets, including an extensive tmRNA database, yielding results that are competitive with existing algorithms. Finally, it is shown that McGenus highlights possible limitations in the free energy scoring function. The algorithm is available as a web-server at http://ipht.cea.fr/rna/mcgenus.php .Comment: 6 pages, 1 figur

Hybrid magnetite nanoparticles/Rosmarinus officinalis essential oil nanobiosystem with antibiofilm activity

Biofilms formed by fungal organisms are associated with drastically enhanced resistance against most antimicrobial agents, contributing to the persistence of the fungi despite antifungal therapy. The purpose of this study is to combine the unique properties of nanoparticles with the antimicrobial activity of the Rosmarinus officinalis essential oil in order to obtain a nanobiosystem that could be pelliculised on the surface of catheter pieces, in order to obtain an improved resistance to microbial colonization and biofilm development by Candida albicans and C. tropicalis clinical strains. The R. officinalis essential oils were extracted in a Neo-Clevenger type apparatus, and its chemical composition was settled by GC-MS analysis. Functionalized magnetite nanoparticles of up to 20 nm size had been synthesized by precipitation method adapted for microwave conditions, with oleic acid as surfactant. The catheter pieces were coated with suspended core/shell nanoparticles (Fe3O4/oleic acid:CHCl3), by applying a magnetic field on nanofluid, while the CHCl3 diluted essential oil was applied by adsorption in a secondary covering treatment. The fungal adherence ability was investigated in six multiwell plates, in which there have been placed catheters pieces with and without hybrid nanoparticles/essential oil nanobiosystem pellicle, by using culture-based methods and confocal laser scanning microscopy (CLSM). The R. officinalis essential oil coated nanoparticles strongly inhibited the adherence ability and biofilm development of the C. albicans and C. tropicalis tested strains to the catheter surface, as shown by viable cell counts and CLSM examination. Due to the important implications of Candida spp. in human pathogenesis, especially in prosthetic devices related infections and the emergence of antifungal tolerance/resistance, using the new core/shell/coated shell based on essential oil of R. officinalis to inhibit the fungal adherence could be of a great interest for the biomedical field, opening new directions for the design of film-coated surfaces with antibiofilm properties

Rapid, modular and reliable construction of complex mammalian gene circuits

We developed a framework for quick and reliable construction of complex gene circuits for genetically engineering mammalian cells. Our hierarchical framework is based on a novel nucleotide addressing system for defining the position of each part in an overall circuit. With this framework, we demonstrate construction of synthetic gene circuits of up to 64 kb in size comprising 11 transcription units and 33 basic parts. We show robust gene expression control of multiple transcription units by small molecule inducers in human cells with transient transfection and stable chromosomal integration of these circuits. This framework enables development of complex gene circuits for engineering mammalian cells with unprecedented speed, reliability and scalability and should have broad applicability in a variety of areas including mammalian cell fermentation, cell fate reprogramming and cell-based assays.Synthetic Biology Engineering Research Center (SA5284-11210)United States. Defense Advanced Research Projects Agency (HR0011-12-C-0067)United States. Defense Advanced Research Projects Agency (DARPA-BAA-11-23)National Science Foundation (U.S.) (CBET-0939511)National Institutes of Health (U.S.). (5-R01-CA155320-02