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Introduction: Application of nanoparticles as radio sensitizer is a promising field to improve efficiency of radiotherapy. Methods: This study was conducted to review nano radio sensitizers. PubMed, Ovid Medline, Science Direct, Scopus, ISI web of knowledge, and Springer databases were searched from 2000 to May 2013 to identify relevant studies. Search was restricted to English language. Results: We included any study that evaluated nanoparticles, volunteer of radio enhancement at radiotherapy on animals or cell lines. Nanoparticles can increase radio sensitivity of tumor cells. This effect was shown in vivo and in vitro, at kilovltage or megavoltage energies, in 24 reviewed studies. Focus of studies was on gold nanoparticles. Radio sensitizing effects of nanoparticles depend on nanoparticles' size, type, concentration, intracellular localization, used irradiation energy and tested cell line. Conclusion: Literature suggests potency of nanoparticles for increasing cell radio sensitivity. Reviewed results are promising and warrant future clinical trials. [ABSTRACT FROM AUTHOR]

Introduction: In the last decades, magnetic nanoparticles have been considered and are being studied for employment in tumor therapy and imaging. Also, alongside their utilization in the role of MRI contrast factors, investigations of targeting tumor cells with biomolecules like anticancer drugs, antibodies, and siRNA, the utility of magnetic nanoparticles is evaluated. This preliminary work aimed to investigate the effects of iron oxide NPs on embryo growth and development with an emphasis on brain morphology and teratogenic effects. Methods: After recognizing the air sac with candling, one hundred sixty fertile eggs of the Ross 308 broiler strains were divided into 8 groups (n=20). Group 1 (control) received 0.3 mL serum normal. Groups 2, 3, and 4 received iron oxide nanoparticles as maghemite with doses of 100, 250, and 500 ppm, respectively. Groups 5, 6, 7, and 8 received iron oxide NPs as magnetite with doses of 100, 250, 500, and 2500 ppm, respectively. Twenty days after injections, death day, chicken, brain, liver, heart, bursa of Fabricius, and spleen weights and teratogenic samples were recorded, and brain tissues from all chickens were collected for histological evaluations. Results: The results demonstrated that iron oxide NPs had teratogenic effects such as the lack of formation of abdominal wall muscles and exposing the heart out of the thorax. Also, alterations were observed in the weight ratio of the liver, spleen, and bursa of Fabricius in experimental groups compared to the control group. In the microscopic assessment of the brain tissue, hyperemia, neuronophagia, edema around vessels, necrosis, and vacuolation of neurons were noticeable. Conclusion: It can be concluded that iron oxide NPs affect the growth and development of embryos and can cross the BBB and penetrate the brain tissue by affecting brain morphology. [ABSTRACT FROM AUTHOR]

In this study, Trastuzumab modified Magnetic Nanoparticles (TMNs) were prepared as a new contrast agent for detecting HER2 (Human epidermal growth factor receptor-2) expression tumors by magnetic resonance imaging (MRI). TMNs were prepared based on iron oxide nanoparticles core and Trastuzumab modified dextran coating. The TMNs core and hydrodynamic size were determined by transmission electron microscopy and dynamic light scattering. TMNs stability and cytotoxicity were investigated. The ability of TMNs for HER2 detection were evaluated in breast carcinoma cell lines (SKBr3 and MCF7 cells) and tumor-bearing mice by MRI and iron uptake determination. The particles core and hydrodynamic size were 9 ± 2.5 and 41 ± 15 nm (size range: 15-87 nm), respectively. The molar antibody/nanoparticle ratio was 3.1-3.5. TMNs were non-toxic to the cells below the 30 μg (Fe)/mL concentration and good stable up to 8 weeks in PBS buffer. TMNs could detect HER2 oncogenes in the cells surface with imagable contrast by MRI. The invivo study in mice bearing tumors indicated that TMNs possessed a good diagnostic ability as HER2 specific contrast agent by MRI. TMNs were demonstrated to be able to selectively accumulate in the tumor cells, with a proper signal enhancement in MRI T2 images. So, the complex may be considered for further investigations as an MRI contrast agent for detection of HER2 expression tumors in human. [ABSTRACT FROM AUTHOR]

In this study, flexible polyurethane (PU) nanocomposite foams were prepared by in situ polymerization. The effects of incorporation of nanoparticles on the morphological and structural developments and the relation between this development and mechanical properties of the PU foam were demonstrated. The effects of three different contents (low, moderate, and high) of nanoclay and multiwall carbon nanotubes (MWNTs) loading on foam morphology, structure, kinetics of foaming reactions, and mechanical properties were separately investigated. By adding MWNTs and nanoclay in foams, the foam morphology improved, in which cell density increased and smaller cells were obtained. The mechanical properties of foam especially tensile strength have been increased in the presence of nanoparticles. With enhancing the nanoclay content, the tensile strength of nanocomposite foam has improved but in the case of MWNTs contrary effects were observed. An increase in nanoparticle amount leads to a lower cell density. In general, the incorporation of both nanoparticles (nanoclay and MWNTs) in the foam structure leads to a lower foaming reaction rate that affects mechanical properties of foams. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 32: E545-E555, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21300 [ABSTRACT FROM AUTHOR]

In this research, simultaneous effects of polyacrylonitrile (PAN) and polyurethane (PU) nanofibers, multi wall carbon nanotubes (MWNTs) and nanoclay incorporation on sound absorption behavior of polyurethane foam were studied. The most important parameters such as nanoparticles content, number and mass per unit area of nanofiber layers and foam thickness were chosen and their influences on sound absorption in a wide band of frequencies were investigated. Applying of both nanoparticles gave rise to considerable improvement in PU foam sound absorption, however in case of MWNTs more satisfied results were observed. Sound absorption tests of simultaneous incorporation of MWNTs and nanoclay showed that the optimized result can be obtained at moderate to high MWNTs percents (0.1-0.15 wt.%) and low percents of nanoclay (0.5 wt.%). On the other hand, by adding PAN or PU nanofiber layers within the PU foam structure, superior sound absorption was achieved. Upper sound absorption by increasing the numbers of nanofiber layers was obtained. Incorporation of PAN nanofiber layers showed a better effect at high mass per unit area (5 g/m), however the higher sound absorption in case of PU nanofiber layers was observed at low mass per unit area (1 g/m). [ABSTRACT FROM AUTHOR]