Design of Cationic Multi-Walled Carbon Nanotubes as Efficient siRNA Vectors for Lung Cancer Xenograft Eradication

Polo-Like Kinase (PLK1) has been identified as a potential target in cancer gene therapy via chemical or genetic inhibitory approaches. The biomedical applications of chemically functionalized carbon nanotubes (f-CNTs) in cancer therapy have been studied due to their ability to efficiently deliver siRNA intracellularly. In this study, we established the capacity of cationic MWNT-NH3+ to deliver the apoptotic siRNA against PLK1 (siPLK1) in Calu6 tumor xenografts by direct intratumoural injections. A direct comparison with cationic liposomes was made. This study validates the PLK1 gene as a potential target in cancer gene therapy including lung cancer, as demonstrated by the therapeutic efficacy of siPLK1:MWNT-NH3+ complexes and their ability to significantly improve animal survival. Biological analysis of the siPLK1:MWNT-NH3+ treated tumors by RT-PCR and Western blot, in addition to TUNEL staining confirmed the biological functionality of the siRNA intratumourally, suggesting that tumor eradication was due to PLK1 knockdown. Furthermore, by using a fluorescently labelled, non-coding siRNA sequence complexed with MWNT-NH3+, we established for the first time that the improved therapeutic efficacy observed in f-CNT-based siRNA delivery is directly proportional to the enhanced siRNA retention in the solid tumor and subsequent uptake by tumor cells after local administration in vivo

Carbon nanotubes allow capture of krypton, barium and lead for multichannel biological X-ray fluorescence imaging

The desire to study biology in situ has been aided by many imaging techniques. Among these, X-ray fluorescence (XRF) mapping permits observation of elemental distributions in a multichannel manner. However, XRF imaging is underused, in part, because of the difficulty in interpreting maps without an underlying cellular ‘blueprint’; this could be supplied using contrast agents. Carbon nanotubes (CNTs) can be filled with a wide range of inorganic materials, and thus can be used as ‘contrast agents’ if biologically absent elements are encapsulated. Here we show that sealed single-walled CNTs filled with lead, barium and even krypton can be produced, and externally decorated with peptides to provide affinity for sub-cellular targets. The agents are able to highlight specific organelles in multiplexed XRF mapping, and are, in principle, a general and versatile tool for this, and other modes of biological imaging

Grazing protection influences soil mesofauna in ungrazed and grazed riparian and upland pastures

The influence of grazing protection caused by streambank fencing on soil mesofauna density is unknown. Our objective was to determine if grazing protection (ungrazed vs. grazed), location (upland vs. riparian pasture), and seasonal (spring vs. fall) treatment effects associated with streambank fencing had a significant influence on soil mesofauna distribution and density. We collected five intact soil cores (0-5 cm depth) in June and October of 2012 from within four treatments consisting of ungrazed and grazed riparian and upland pastures associated with streambank fencing along an 800-m reach of the Lower Little Bow River in southern Alberta, Canada. Soil mesofauna were extracted and densities of Acari (mites) taxa, Collembola (springtails) taxa, and other mesofauna were determined. Grazing protection resulted in a significant (P ≤ 0.05) negative response of Astigmata mite densities for the upland pasture, and a positive response for Oribatida mites and total Collembola, and Hypogastruridae and Onychiuridae springtails for both pastures. Location and season had a significant influence on Acari and Collembola taxa, but the effects were dependent on interaction effects. We conclude that grazing protection influenced certain soil mesofauna in pastures associated with streambank fencing, and this may influence decomposition of soil organic matter, nutrient cycling, and soil structure in associated pastures. © 2014 The Society for Range Management.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

L'eau est-elle un element structurant de l'espace? Existe-t-il une geographie de l'eau et quelle pourrait en etre la specificite? Quelle peut-etre la place des geographes dans la gestion de l'eau?

Tavola rotonda sulla ruolo dell'acqua nella strutturazione territoriale, tenuta in occasione del 2\ub0 seminario europeo di geografia dell'acqu

Improved chemical and mechanical stability of peptoid nanosheets by photo-crosslinking the hydrophobic core.

Peptoid nanosheets can be broadly functionalized for a variety of applications. However, they are susceptible to degradation when exposed to chemical or mechanical stress. To improve their strength, photolabile monomers were introduced in order to crosslink the nanosheet interior. Photo-crosslinking produced a more robust material that can survive sonication, lyophilization, and other biochemical manipulations

Improved chemical and mechanical stability of peptoid nanosheets by photo-crosslinking the hydrophobic core

Peptoid nanosheets can be broadly functionalized for a variety of applications. However, they are susceptible to degradation when exposed to chemical or mechanical stress. To improve their strength, photolabile monomers were introduced in order to crosslink the nanosheet interior. Photo-crosslinking produced a more robust material that can survive sonication, lyophilization, and other biochemical manipulations

Margaret Cavendish’s Female Fairground Performers

The vast majority of the documents – visual as well as textual – on which we base our knowledge of early modern performers, were produced by men, and most concentrate squarely on male performers. Exceptionally, the 195th of the Sociable Letters of Margaret Cavendish contains a substantial description of professional performers neither written by a man, nor sidelining the contribution of women to early modern performance culture. Having noted that typical fairground performances involve: ‘Dancers on the Ropes, Tumblers, Jugglers, Private Stage-Players, Mountebanks, Monsters, and several Beasts’, Cavendish focuses on two ‘Sights and Shews’ in which female performers take centre stage. In these, Cavendish (c.1623-73), natural philosopher, poet and playwright, draws on eye-witness experiences gathered during her mid-seventeenth-century years of royalist exile, when she overcame the restrictions inhibiting those of her class and gender from joining spectators at public stages by hiring rooms for private views of her favourite acts at Antwerp’s fairgrounds. Drawing on my ongoing archival and cultural researches into performing monsters, mountebanks, quacks and itinerant commedia dell’arte troupes, my chapter analyses and contextualizes Cavendish’s description of female fairground performers which, despite its essentially literary character, contains considerable documentary value for an understanding of early modern women on stage

Double functionalization of carbon nanotubes with purine and pyrimidine derivatives.

Herein, we have developed a synthetic strategy for the covalent double functionalization of single-walled carbon nanotubes (SWCNTs) with a combination of purine-pyrimidine and purine-purine nucleobase systems. The nucleobases were introduced on the sidewall of oxidized SWCNTs through 1,3-dipolar cycloaddition and by amidation of the carboxylic acids located at the tips and defect sites of the nanotubes. The new nanohybrids were characterized by transmission electron microscopy, thermogravimetric analysis, FTIR and Raman spectroscopy, magic-angle spinning NMR spectroscopy, and Kaiser test. The nucleobase/SWCNT conjugates can be envisaged for the modulation of the interactions with nucleic acids by means of base pairing, thereby opening new possibilities in the development of DNA/CNT nanobioconjugates.journal articleresearch support, non-u.s. gov't2013 Jul2013 05 22importe