Occurrence, behavior and effects of nanoparticles in the environment.

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Functional Nucleic Acid Sensors

Nanoscience has matured significantly during the last decade as it has transitioned from bench top science to applied technology. Presently, nanomaterials are used in a wide variety of commercial products such as electronic components, sports equipment, sun creams and biomedical applications. There are few studies of the long-term consequences of nanoparticles on human health, but governmental agencies, including the United States National Institute for Occupational Safety and Health and Japan's Ministry of Health, have recently raised the question of whether seemingly innocuous materials such as carbon-based nanotubes should be treated with the same caution afforded known carcinogens such as asbestos. Since nanomaterials are increasing a part of everyday consumer products, manufacturing processes, and medical products, it is imperative that both workers and end-users be protected from inhalation of potentially toxic NPs. It also suggests that NPs may need to be sequestered into products so that the NPs are not released into the atmosphere during the product's life or during recycling. Further, non-inhalation routes of NP absorption, including dermal and medical injectables, must be studied in order to understand possible toxic effects. Fewer studies to date have addressed whether the body can eventually eliminate nanomaterials to prevent particle build-up in tissues or organs. This critical review discusses the biophysicochemical properties of various nanomaterials with emphasis on currently available toxicology data and methodologies for evaluating nanoparticle toxicity (286 references).

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Toxicity of nanomaterials

2.3. Ionic Liquids (ILs) 5374 2.4. Complexation Reactions on Oxidized CNTs 5375 2.5. Halogenation 5376 2.6. Cycloaddition Reactions 5377 2.7. Radical Additions 5379 2.8. Nucleophilic Additions 5381 2.9. Electrophilic Additions 5381 2.10. Electrochemical Modifications 5381 2.11. Plasma-Activation 5381 2.12. Mechanochemical Functionalizations 5382 3. Noncovalent Interactions 5382 3.1. Polynuclear Aromatic Compounds 5382 3.2. Interactions with Other Substances 5384 3.3. Interactions with Biomolecules 5385 4. Endohedral Filling 5386 4.1. Encapsulation of Fullerenes 5386 4.2. Encapsulation of Organic Substances 5387 4.3. Encapsulation of Inorganic Substances 5387 5. Decoration of CNTs with Metal Nanoparticles 5388 5.1. Covalent Linkage 5388 5.2. Direct Formation on Defect Sites 5388 5.3. Electroless Deposition 5388 5.4. Electrodeposition 5389 5.5. Chemical Decoration 5390 5.6. Deposition of Nanoparticles onto CNTs 5391 5.7. π-π Stacking and Electrostatic Interactions 5391 6. Concluding Remarks 5392 7. Acknowledgments 5392 8. References 5392

Current progress on the chemical modification of carbon nanotubes.

Diagnostics and Therapy Guanying Chen,‡,† Indrajit Roy,†,§ Chunhui Yang,*,‡ and Paras N. Prasad*,† †Institute for Lasers, Photonics, and Biophotonics and Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260, United States ‡School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China Department of Chemistry, University of Delhi, Delhi 110007, India

Nanochemistry and Nanomedicine for Nanoparticle-based Diagnostics and Therapy

A gold nanoparticle-based detection strategy for ATP assays. In the absence of ATP, gold nanoparticles are not stabilized by the rigid duplex, thus they are readily aggregated by salt (solution displaying blue colors); in contrast induces a duplex-to-aptamer structural switching, liberating a random coil-like ssDNA. Gold nanoparticles are stabilized by the liberated ssDNA, showing high resistance to salt-induced aggregation (solution staying in red).

A gold nanoparticle-based aptamer target binding readout for ATP assay

The cytotoxicity of cadmium based, aqueous phase - Synthesized, quantum dots and its modulation by surface coating

Biodistribution of functionalized multiwall carbon nanotubes in mice

This study examined the influence of multi-walled carbon nanotubes (MWNTs) on the growth of the unicellular protozoan Tetrahymena pyriformis. Contrary to the findings from most other investigations, our experiment indicated that MWNTs stimulated growth of the cells cultured in proteose peptone yeast extract medium (PPY). Atomic force microscopy images and thermogravimetric analysis showed the spontaneous formation of peptone-MWNT conjugates in the medium by noncovalent binding. Uptake of large amounts of the conjugates by Tetrahymena pyriformis was responsible for growth stimulation, evidenced by images with fluorescently labelled peptone. After the PPY medium was replaced by a filtrated pond water medium (FPW), however, inhibition of the growth of cells exposed to MWNTs occurred. Measurements of the level of malondialdehyde and superoxide dismutase activity demonstrated further that MWNTs might be either toxic or nontoxic, depending on the medium used to cultivate Tetrahymena pyriformis. The biological effects of the interaction of MWNTs with some composites in culture media would be helpful for understanding the mechanisms of the toxicity of carbon nanotubes to living systems.

Dependence of the cytotoxicity of multi-walled carbon nanotubes on the culture medium

Multi-walled carbon nanotubes (MWNTs) irradiated with γ-rays were subjected to chemical modification with thionyl chloride and decylamine. Products from chemical treatment were characterized by both FTIR and Raman spectra. Element analysis (EA) and thermogravimetric analysis (TGA) for the modified soluble MWNTs (s-MWNTs) indicated that γ-radiation increased the concentration of functional groups bound to MWNTs, which arose due to the increasing number of defect sites created on the MWNTs by γ-photons. Compared with untreated MWNTs, γ-irradiation significantly enhanced the solubility of MWNTs in acetone and tetrahydrofuran (THF). We therefore conclude that γ-irradiation provides a novel approach to prepare various functionalized modifications of carbon nanotubes (CNTs).

https://iopscience.iop.org/article/10.1088/0957-4484/16/10/065/pdf

Wenxin Li

Papers

A gold nanoparticle-based aptamer target binding readout for ATP assay

The cytotoxicity of cadmium based, aqueous phase - Synthesized, quantum dots and its modulation by surface coating

Biodistribution of functionalized multiwall carbon nanotubes in mice

Dependence of the cytotoxicity of multi-walled carbon nanotubes on the culture medium

The effects of γ-irradiation dose on chemical modification of multi-walled carbon nanotubes