Biodegradable Passion Fruit‐Like Nano‐Architectures as Carriers for Cisplatin Prodrug

Accumulation of inorganic nanostructures in the excretory system organs increases their likelihood of toxicity and interference with common medical diagnoses. Thus, one of the major concerns regarding their clinical translation is related to their persistence in organisms. Here the authors demonstrate that nano‐architectures composed by hollow silica nanocapsules embedding arrays of ultrasmall gold nanoparticles undergo biodegradation in cellular environment affording small, potentially clearable building blocks. Furthermore, the authors present their exploitation in glutathione‐triggered release of covalently loaded cisplatin prodrug. This endogenously triggered release leads to high cytotoxicity to human pancreatic carcinoma cells, setting the way for promising applications to synergistic dual chemo/radio‐therapy and radio‐imaging.     

Biochemical and biomedical applications of multifunctional magnetic nanoparticles: a review

Nanotechnology offers tremendous potential for future medical diagnosis and therapy. Various types of nanoparticles have been extensively studied for numerous biochemical and biomedical applications. Magnetic nanoparticles are well-established nanomaterials that offer controlled size, ability to be manipulated by an external magnetic field, and enhancement of contrast in magnetic resonance imaging. As a result, these nanoparticles could have many applications including bacterial detection, protein purification, enzyme immobilization, contamination decorporation, drug delivery, hyperthermia, etc. All these biochemical and biomedical applications require that these nanoparticles should satisfy some prerequisites including high magnetization, good stability, biocompatibility, and biodegradability. Because of the potential benefits of multimodal functionality in biomedical applications, in this account highlights some general strategies to generate magnetic nanoparticle-based multifunctional nanostructures. After these magnetic nanoparticles are conjugated with proper ligands (e.g., nitrilotriacetate), polymers (e.g., polyacrylic acid, chitosan, temperature- and pH-sensitive polymers), antibodies, enzymes, and inorganic metals (e.g., gold), such biofunctional magnetic nanoparticles exhibit many advantages in biomedical applications. In addition, the multifunctional magnetic nanoparticles have been widely applied in biochemical fields including enzyme immobilization and protein purification.     

Protein-assisted synthesis route of metal nanoparticles: exploration of key chemistry of the biomolecule

Abstract  

Essentially, biomolecule assisted synthesis of inorganic nanoparticles can be divided into two categories. One uses multi-domain protein cages (template) and other relies on the self-assembly of the biomolecules including small peptides, DNA, and denatured protein. Protein templated synthesis of various nanomaterials is relatively well understood as the cages of the biological macromolecules and their specific interaction with inorganic ions ultimately dictate the size and crystallinity of the nanomaterials. On the other hand formation of nanoparticles using protein in the cost of the native structural integrity for the self-assembly is not well understood till date. In the present work we report a protein-assisted synthesis route to prepare highly crystalline 3–5 nm gold nanoparticles, which relies systematic thermal denaturation of a number of proteins and protein mixture from Escherichia coli in absence of any reducing agent. By using UV–vis, circular dichroism spectroscopy, and high-resolution transmission electron microscopy we have explored details of the associated biochemistry of the proteins dictating kinetics, size, and crystallinity of the nanoparticles. The kinetics of nanoparticles formation in this route, which is sigmoidal in nature, has been modelled in a simple scheme of autocatalytic process. Interestingly, the protein-capped as prepared Au nanoparticles are found to serve as effective catalyst to activate the reduction of 4-nitrophenol in the presence of NaBH₄. The kinetic data obtained by monitoring the reduction of 4-nitrophenol by UV/vis-spectroscopy revealing the efficient catalytic activity of the nanoparticles have been explained in terms of the Langmuir–Hinshelwood model. The methodology and the details of the protein chemistry presented here may find relevance in the protein-assisted synthesis of inorganic nanostructures in general.     

Phase transfer of highly monodisperse iron oxide nanocrystals with Pluronic F127 for biomedical applications

Iron oxide nanoparticles made from the thermal decomposition method are highly uniform in all respects (size, shape, composition and crystallography), making them ideal candidates for many bioapplications. The surfactant coating on the as-synthesized nanoparticles renders the nanoparticles insoluble in aqueous solutions. For biological applications nanoparticles must be water soluble. Here we demonstrate the phase transfer of our nanoparticles with the biocompatible copolymer Pluronic F127. Transmission electron microscopy, Fourier transform infrared spectroscopy and dynamic light scattering indicate that the nanoparticles are coated discretely. Magnetic measurements show that the nanoparticles remain superparamagnetic with saturation magnetization ∼96% of the maximum theoretical value.     

Design and fabrication of non-superparamagnetic high moment magnetic nanoparticles for bioapplications

We present a new type of magnetic nanoparticles for bioapplications. Multilayered nanodisks consisting of two magnetic layers separated by a non-magnetic layer with two capping layers were designed and fabricated. Two key magnetic requirements for bioapplications, a high saturation magnetic moment and a near-zero remanence, were achieved through the magnetostatic interlayer coupling between two magnetic layers. Capping layers provide functionalization sites for biomolecule attachment. A pillar-template-based synthesis method was employed for fabrication. Nanodisks with a diameter of 70 nm and a thickness of 60 nm were produced in large quantity. The magnetic characterization shows that each nanodisk possesses a magnetic moment equivalent to 100 10-nm Co nanoparticles and a near-zero remanent moment.     

Chiral Ag and Au Nanomaterials Based Optical Approaches for Analytical Applications

Sensing of chiral compounds has gained great attentions for many decades. Chiral nanomaterials with a greater surface area, optical properties, and stability have however not been well realized in this field. Herein, strategies for the preparation of chiral Ag and Au nanomaterials are focused upon, including Ag and Au nanoparticles conjugated with chiral molecules with/without containing fluorophores, chiral nanoassemblies of Ag and Au nanoparticles, and chiral Ag and Au nanoclusters. The chirality of nanomaterials originates from their core and/or ligand, meanwhile that for nanoassemblies results from their complex spatial configuration. An emphasis is given to circular dichroism, colorimetry/UV–vis absorption, and fluorescence detection modes for sensing enantiomers and achiral analytes using the chiral Ag and Au nanomaterials. Several interesting examples for quantitation of DNA, proteins, peptides, drugs, and pollutants are provided to highlight their potential as sensitive and selective nanomaterials for enantiomer recognition and sensing of achiral analytes. Several important issues to be solved when using chiral nanomaterials for chiral recognition are specified. Some strategies for improving the sensitivity and selectivity of chiral nanomaterials for chiral recognition are suggested. The aim is to bring more attention to the potential of chiral nanomaterials for sensing important analytes such as chiral drugs.     

Magnetic Anisotropic Particles: Toward Remotely Actuated Applications

The latest breakthroughs in the synthetic preparation of nanomaterials have led to an expanding library of novel, complex and shape controlled structures with unique characteristics. Anisotropic Janus particles (JPs) are asymmetrical and are able to endow diverse chemical and physical characteristics with directionality within a single particle. They are typically distributed into three classes, viz polymeric, inorganic and polymeric‐inorganic and is made in a variation of morphologies including spherical, mushroom, snowman shaped, rod or cylindrical. Herein, we focus on JPs with a magnetic component, with emphasis on their fabrication, unique characteristics and recent applications.     

无机纳米发光材料研究展望:如何走出自己的舒适区?

无机纳米发光材料由于其独特的发光性质,具有广泛的应用前景。本文结合作者的科研经历,展望了无机纳米发光材料未来的发展机遇和挑战,聚焦该领域前沿“痛点”和“冷门”,探讨研究工作如何面向国家重大需求。倡议科学家应走出自己的研究舒适区,树立自己的标签性工作,共同推进无机纳米发光材料研究的可持续发展。     

Uptake of FITC Labeled Silica Nanoparticles and Quantum Dots by Rice Seedlings: Effects on Seed Germination and Their Potential as Biolabels for Plants

The use of fluorescent nanomaterials with good photostability and biocompatibility in live imaging of cells has gained increased attention. Even though several imaging techniques have been reported for mammalian cells, very limited literatures are available for nanomaterial based live imaging in plant system. We studied the uptake ability of two different nanomaterials, the highly photostable CdSe quantum dots and highly biocompatible FITC-labeled silica nanoparticles by rice seedlings which could provide greater opportunities for developing novel in vivo imaging techniques in plants. The effects of these nanomaterials on rice seed germination have also been studied for analyzing their phytotoxic effects on plants. We observed good germination of seeds in the presence of FITC-labeled silica nanoparticles whereas germination was arrested with quantum dots. The uptake of both the nanomaterials has been observed with rice seedlings, which calls for more research for recommending their safe use as biolabels in plants.     

纳米尺度下的局域场增强研究进展

金属纳米颗粒的等离激元共振引起的局域场增强效应,对显微成像、光谱学、半导体器件、非线性光学等诸多领域都具有极大的应用潜力。尤其是在光学纳米材料领域,通过亚波长金属纳米颗粒与电介质的组合引起局域场增强效应,提高了纳米材料的光学性能,并促进纳米材料在光学领域的应用。本文主要综述几种常见纳米结构所产生的局域场增强效应及其应用,详细介绍并总结了金属纳米材料的不同结构参数与局域场增强的关系及局域场增强在非线性光学、光谱学、半导体器件等领域的应用。未来,随着对金属纳米材料的研究愈发深入,局域场增强的应用将更加广泛,这将对诸多领域的发展产生重要影响。     

Monodispersed β-Glycerophosphate-Decorated Bioactive Glass Nanoparticles Reinforce Osteogenic Differentiation of Adipose Stem Cells and Bone Regeneration In Vivo

Design and development of highly bioactive nanoscale biomaterials with enhanced osteogenic differentiation on adipose stem cells is rather important for bone regeneration and attracting much attention. Herein, monodispersed glycerophosphate-decorated bioactive glass nanoparticles (BGN@GP) are designed and their effect is investigated on the osteogenic differentiation of adipose mesenchymal stem cells (ADMSCs) and in vivo bone regeneration. The surface-modified BGN@GP can be efficiently taken by ADMSCs and shows negligible cytotoxicity. The in vitro results reveal that BGN@GP significantly enhances the alkaline phosphatase activity and calcium biominerialization of ADMSCs either under normal or osteoinductive medium as compared to BGNs. Further studies find that the osteogenic genes and proteins including Runx2 and Bsp in ADMSCs are significantly improved by BGN@GP even under normal culture medium. The in vivo animal experiment confirms that BGN@GP significantly promotes the new bone formation in a rat skull defect model. This study suggests that bioactive small molecule decorating is an efficient strategy to improve the osteogenesis capacity of inorganic ceramics nanomaterials.     

Nanomaterials and Water Purification: Opportunities and Challenges

Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly ameliorated using nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes and nanoparticle enhanced filtration among other products and processes resulting from the development of nanotechnology. Innovations in the development of novel technologies to desalinate water are among the most exciting and promising. Additionally, nanotechnology-derived products that reduce the concentrations of toxic compounds to sub-ppb levels can assist in the attainment of water quality standards and health advisories. This article gives an overview of the use of nanomaterials in water purification. We highlight recent advances on the development of novel nanoscale materials and processes for treatment of surface water, groundwater and industrial wastewater contaminated by toxic metal ions, radionuclides, organic and inorganic solutes, bacteria and viruses. In addition, we discuss some challenges associated with the development of cost effective and environmentally acceptable functional nanomaterials for water purification.     

Glow discharge plasma electrolysis for nanoparticles synthesis

There are many methods available to synthesize nanomaterials and the glow discharge plasma electrolysis is a novel and a green method in this category. It is seen that most of the papers are published after 2005 and the interest in it is growing due to its applicability in the industry for preparing nanomaterials at large scale. But, only few results are available yet and most of them are on metal nanoparticle preparation, so that more studies are needed to understand the nature of growth of the nanoparticles under glow discharge in liquid and its applicability in preparing semi-conductor nanomaterials. Many have tried many methods to prepare nanoparticles by the glow discharge and a review like this is the need of the time to understand its present status that helps to modify the present situation to a better one. This review classifies all the available methods of nanomaterials synthesis in liquid by glow discharge in to three and it is discussed in detail.     

Synthesis and Application of Inorganic Nanoparticles as Lubricant Components – a Review

Recent achievements in chemistry and technology of nanosized inorganic particles provide possibility of synthesis in various metal oxides, chalcogenides, and so on. Surface modification of nanoparticles in some cases provides formation of their stable dispersions in liquid hydrocarbons. State of art in the field of inorganic nanoparticles’ synthesis and their application in tribology is discussed. Special attention is paid to synthesis of surface-capped and bare molybdenum sulfide nanoparticles and to testing thereof as friction-modifying additives for liquid lubricants. Differences in action mechanism of MoS_x nanoparticles and ‘molecular’ molybdenum complexes are discussed. Future trends of inorganic nanoparticles use as lubricant additives are suggested.     

Inorganic fullerenes and nanotubes: Wealth of materials and morphologies

It is already well established today that numerous materials form closed-cage structures, of which carbon fullerenes and nanotubes are a special case [1]. Inorganic fullerene-like nanoparticles (designated IF) and inorganic nanotubes (INT) have been produced by different routes and experimental techniques, achieving persistent growth of a variety of materials and structural wealth within them. The research in this area has focused on synthesizing new IF and INT materials and understanding their different properties as well as scaling up the synthetic process in order to make it suitable for industrial applications. In this review, the main synthetic procedures to obtain inorganic fullerene-like nanoparticles and nanotubes will be discussed alongside with the different mechanisms that affect the morphology of the final product. The main differences between the morphologies will be presented. Some general considerations relating the properties of the parent compound with the morphology of the product will be mentioned.     

High pressure structural phase transitions of TiO_2 nanomaterials

Recently, the high pressure study on the TiO_2 nanomaterials has attracted considerable attention due to the typical crystal structure and the fascinating properties of TiO_2 with nanoscale sizes. In this paper, we briefly review the recent progress in the high pressure phase transitions of TiO_2 nanomaterials. We discuss the size effects and morphology effects on the high pressure phase transitions of TiO_2 nanomaterials with different particle sizes, morphologies, and microstructures. Several typical pressure-induced structural phase transitions in TiO_2 nanomaterials are presented, including size-dependent phase transition selectivity in nanoparticles, morphology-tuned phase transition in nanowires, nanosheets,and nanoporous materials, and pressure-induced amorphization(PIA) and polyamorphism in ultrafine nanoparticles and TiO_2-B nanoribbons. Various TiO_2 nanostructural materials with high pressure structures are prepared successfully by high pressure treatment of the corresponding crystal nanomaterials, such as amorphous TiO_2 nanoribbons, α-PbO_2-type TiO_2 nanowires, nanosheets, and nanoporous materials. These studies suggest that the high pressure phase transitions of TiO_2 nanomaterials depend on the nanosize, morphology, interface energy, and microstructure. The diversity of high pressure behaviors of TiO_2 nanomaterials provides a new insight into the properties of nanomaterials, and paves a way for preparing new nanomaterials with novel high pressure structures and properties for various applications.     

Characterization of exposure to silver nanoparticles in a manufacturing facility

An assessment of the extent of exposure to nanomaterials in the workplace will be helpful in improving the occupational safety of workers. It is essential that the exposure data in the workplace are concerned with risk management to evaluate and reduce worker exposure. In a manufacturing facility dealing with nanomaterials, some exposure data for gas-phase reactions are available, but much less information is available regarding liquid-phase reactions. Although the potential for inhaling nanomaterials in a liquid-phase process is less than that for gas-phase, the risks of exposure during wet-chemistry processes are not negligible. In this study, we monitored and analyzed the exposure characteristics of silver nanoparticles during a liquid-phase process in a commercial production facility. Based on the measured exposure data, the source of Ag nanoparticles emitted during the production processes was indentified and a mechanism for the growth of Ag nanoparticle released is proposed. The data reported in this study could be used to establish occupational safety guidelines in the nanotechnology workplace, especially in a liquid-phase production facility.     

Organometal Halide Perovskites: Bulk Low‐Dimension Materials and Nanoparticles

Organometal halide perovskites (hybrid perovskites) contain an anionic metal–halogen‐semiconducting framework and charge‐compensating organic cations. As hybrid materials, they combine useful properties of both organic and inorganic materials, such as plastic mechanical properties and good electronic mobility related to organic and inorganic material, respectively. They are prepared from abundant and low cost starting compounds. The perovskite stoichiometry is associated with the dimensionality of its inorganic framework, which can vary from three to zero, 3D consisting of corner‐sharing MX₆ octahedra, and 0D consisting of isolated octahedra. Small‐sized organic cations can fit into the MX₆ octahedra of the 3D framework and in all dimensions organic cations surround the inorganic framework. Regarding the low dimensionality in the material, this refers to at least one of its dimensions being shorter than approximately 100 nanometers. These materials should be considered as genuine nanomaterials or as bulk materials depending on whether they have three or less than three dimensions on the nanoscale, respectively. In principle, hybrid perovskite nanoparticles can be prepared with different shapes and with inorganic framework dimensionalities varying from 0D to 3D, and this also applies to the bulk material. This report is mainly focused on the unique properties of organometal halide perovskite nanoparticles.     

Toxicity and cellular uptake of gold nanoparticles: what we have learned so far?

Gold nanoparticles have attracted enormous scientific and technological interest due to their ease of synthesis, chemical stability, and unique optical properties. Proof-of-concept studies demonstrate their biomedical applications in chemical sensing, biological imaging, drug delivery, and cancer treatment. Knowledge about their potential toxicity and health impact is essential before these nanomaterials can be used in real clinical settings. Furthermore, the underlying interactions of these nanomaterials with physiological fluids is a key feature of understanding their biological impact, and these interactions can perhaps be exploited to mitigate unwanted toxic effects. In this Perspective we discuss recent results that address the toxicity of gold nanoparticles both in vitro and in vivo, and we provide some experimental recommendations for future research at the interface of nanotechnology and biological systems.     

Occupational exposure limits for nanomaterials: state of the art

Assessing the need for and effectiveness of controlling airborne exposures to engineered nanomaterials in the workplace is difficult in the absence of occupational exposure limits (OELs). At present, there are practically no OELs specific to nanomaterials that have been adopted or promulgated by authoritative standards and guidance organizations. The vast heterogeneity of nanomaterials limits the number of specific OELs that are likely to be developed in the near future, but OELs could be developed more expeditiously for nanomaterials by applying dose–response data generated from animal studies for specific nanoparticles across categories of nanomaterials with similar properties and modes of action. This article reviews the history, context, and approaches for developing OELs for particles in general and nanoparticles in particular. Examples of approaches for developing OELs for titanium dioxide and carbon nanotubes are presented and interim OELs from various organizations for some nanomaterials are discussed. When adequate dose–response data are available in animals or humans, quantitative risk assessment methods can provide estimates of adverse health risk of nanomaterials in workers and, in conjunction with workplace exposure and control data, provide a basis for determining appropriate exposure limits. In the absence of adequate quantitative data, qualitative approaches to hazard assessment, exposure control, and safe work practices are prudent measures to reduce hazards in workers.