Ecotoxicity and analysis of nanomaterials in the aquatic environment

Nanotechnology is a major innovative scientific and economic growth area. However nanomaterial residues may have a detrimental effect on human health and the environment. To date there is a lack of quantitative ecotoxicity data, and recently there has been great scientific concern about the possible adverse effects that may be associated with manufactured nanomaterials. Nanomaterials are in the 1- to 100-nm size range and can be composed of many different base materials (carbon, silicon and metals, such as gold, cadmium and selenium) and they have different shapes. Particles in the nanometer size range do occur both in nature and as a result of existing industrial processes. Nevertheless, new engineered nanomaterials and nanostructures are different because they are being fabricated from the “bottom up”. Nanomaterial properties differ compared with those of the parent compounds because about 40–50% of the atoms in nanoparticles (NPs) are on the surface, resulting in greater reactivity than bulk materials. Therefore, it is expected that NPs will have different biological effects than parent compounds. In addition, release of manufactured NPs into the aquatic environment is largely an unknown. The surface properties and the very small size of NPs and nanotubes provide surfaces that may bind and transport toxic chemical pollutants, as well as possibly being toxic in their own right by generating reactive radicals. This review addresses hazards associated and ecotoxicological data on nanomaterials in the aquatic environment. Main weaknesses in ecotoxicological approaches, controversies and future needs are discussed. A brief discussion on the scarce number of analytical methods available to determinate nanomaterials in environmental samples is included.     

Impact of nanomaterials on high-throughput separation methodologies

Due to the unique properties, such as their large surface to volume ratio and easy modification, nanomaterials have recently been studied as effective sorbents in the field of separation science. It has proven to be more effective and efficient to use nanoparticles (NPs) as a stationary phase in solid-phase extraction separation. In addition, NPs can be also used as buffer additives in capillary electrophoresis separation. This review highlights recent developments in high-throughput separation methodologies employing nanomaterials such as carbon nanotubes, gold nanoparticles and magnetic NPs etc.     

Health impact and safety of engineered nanomaterials

Many engineered nanomaterials (NMs) are being synthesized and explored for potential use in consumer and medical products. Already, nanoparticles (NPs) of titanium dioxide (TiO(2)), zinc oxide (ZnO), silver (Ag) and other metals or their oxides are present in commercial products such as sunscreens, cosmetics, wound dressings, surgical tools, detergents, automotive paints and tires. More recent and advanced FDA-approved use of NMs includes quantum dots (QDs) in live cell imaging, zirconium oxides in bone replacement and prosthetic devices and nanocarriers in drug delivery. The benefits from nanotechnology are aplenty, comprising antimicrobial activities, scratch- and water-resistance, long-lasting shine, improved processor speeds and better display resolution, to name a few. While developers of these products often focus on the exciting beneficial aspects of their products, safety and toxicity issues are often not discussed in detail. Long-term effects such as chronic exposure and environmental pollution are even less documented. Along with widespread manufacture and use of NMs, concerns for occupational hazards, proper handling, disposal, storage, shipping and clean up are expected to rise. This review focus on the possible biological impact of engineered NPs, serving as a reminder that nanomaterials can become a double-edged sword if not properly handled.     

Estrogen-active nonylphenols from an isomer-specific viewpoint: a systematic numbering system and future trends

4-Nonylphenols (NPs) are very important environmentally relevant substances. They are persistent, toxic, endocrine-disrupting chemicals that are priority hazardous substances of the EU Water Framework Directive. NPs are degradation products of 4-nonylphenol ethoxylates (NPEs), a widely used group of nonionic surfactants. The technical synthesis of NP leads to a complex mixture of NPs consisting of isomeric compounds that have different branched nonyl side chains. It has recently become clear that an isomer-specific view is absolutely necessary when it comes to correctly evaluating the biological effects of NPs and their behavior in the environment, including degradation processes. To rationalize the identification of individual NP isomers in scientific studies, we have developed a numbering system for all possible NP isomers that follows the IUPAC rules of substituent characterization in alkylphenols. The 211 possible constitutional isomers of NP are numbered according to a hierarchical and logical system. In the future, multidimensional coupling systems—for example GC×GC-TOF-MS—will be needed to study these highly complex class of substances. Electronic Supplementary Material Supplementary material is available for this article at     

Recent Developments in the Plant‐Mediated Green Synthesis of Ag‐Based Nanoparticles for Environmental and Catalytic Applications

Among different metallic nanoparticles, sliver nanoparticles (Ag NPs) are one of the most essential and fascinating nanomaterials. Importantly, among the metal based nanoparticles, Ag NPs play a key role in various fields such as biomedicine, biosensors, catalysis, pharmaceuticals, nanoscience and nanotechnology, particularly in nanomedicine. A main concern about the chemical synthesis of Ag NPs is the production of hazardous chemicals and toxic wastes. To overcome this problem, many research studies have been carried out on the green synthesis of Ag NPs using green sources such as plant extracts, microorganisms and some biopolymers without formation of hazardous wastes. Among green sources, plants could be remarkably valuable to exploring the biosynthesis of Ag NPs. In this review, the green synthesis of Ag‐based nanocatalysts such as Ag NPs, AgPd NPs, Au?Ag NPs, Ag/AgPd NPs, Ag/Cu NPs, Ag@AgCl NPs, Au?Ag@AgCl nanocomposite, Ag?Cr‐AC nanocomposite and Ag NPs immobilized on various supports such as Natrolite zeolite, bone, ZnO, seashell, hazelnut shell, almond shell, SnO₂, perlite, ZrO₂, TiO₂, α‐Al₂O₃, CeO₂, reduced graphene oxide (rGO), h‐Fe₂O₃@SiO₂, and Fe₃O₄ using numerous plant extracts as reducing and stabilizing agents in the absence of hazardous surfactant and capping agents has been focused. This work describes the state of the art and future challenges in the biosynthesis of Ag‐based nanocatalysts. The fact about the application of living plants in metal nanoparticle (MNPs) industry is that it is a more economical and efficient biosynthesis biosynthetic procedure. In addition, the catalytic activities of the synthesized, Ag‐based recyclable nanocatalysts using various plant extracts in several chemical reactions such as oxidation, reduction, coupling, cycloaddition, cyanation, epoxidation, hydration, degradation and hydrogenation reactions have bben extensively discussed.     

Recent development in nanomaterials fabricated paper-based colorimetric and fluorescent sensors: A review

The paper-based sensing devices have drawn a broad interest in analytical chemistry for colorimetric and fluorescent-based analysis of biological, environmental, clinical, and food samples. It is due to the simple, rapid, biodegradable, user-friendly, less expensive, and low waste generation into the environment. Here, the recent development of paper-based sensors fabricated with different noble metal nanoparticles (NPs) and semiconductor and carbon quantum dots (QDs) is demonstrated to analyze several chemical substances from various samples. User-friendly and portable recording devices such as digital cameras, smartphones, scanners, etc. along with color detecting softwares are employed to measure the color intensity of nanomaterials fabricated paper devices after the deposition of a sample solution containing various chemical substances. The advantages and disadvantages of incorporating nanomaterials in the paper substrate (direct deposition, inkjet printing, screen printing and wax printing) are illustrated. The mechanism for colorimetric, fluorescence, phosphorescence, and chemiluminescence sensing using noble metal NPs (Ag, Cu, and Au), semiconductors, and carbon QDs for the determination of metal ions, anions, pesticides, biomolecules, and other toxic chemical substances are discussed. Thus, this review article would be highly useful for scientists and researchers to design colorimetric sensors to monitor chemical toxicants in clinical, environment, foods, and many other related samples.     

Fluorescent nanoparticles for chemical and biological sensing

Fluorescent nanoparticles (NPs), including quantum dots (QDs), dye-doped NPs, and rare earth-based NPs, etc., have been a major focus of research and development during the past decade. The impetus behind such endeavors can be attributed to their unique chemical and optical properties, such as bright fluorescence, high photostability, large Stocks shift and flexible processability. The introduction of fluorescent NPs into analytical chemistry has opened up new venues for fluorescent analysis. In this review...     

π-Conjugated Copper Phthalocyanine Nanoparticles as Highly Sensitive Sensor for Colorimetric Detection of Biomarkers

Though numerous nanomaterials with enzyme-like activities have been utilized as probes and sensors for detecting biological molecules, it is still challenging to construct highly sensitive detectors for biomarkers using polymeric materials. Benefiting from the π-d delocalization effect of electrons, excellent metal-chelating property, high electron transferability, and good chemical stability of π-conjugated phthalocyanine, the design of the copper phthalocyanine-based conjugated polymer nanoparticles (Cu-PcCP NPs) as a colorimetric sensor for a variety of biomarkers is reported. The Cu-PcCP NPs are synthesized through a simple microwave-assisted polymerization, and their chemical structures are thoroughly characterized. The colorimetric results of Cu-PcCP NPs demonstrate excellent peroxidase-like detecting activity and also great substrate selectivity than most of the reported Cu-based nanomaterials. The Cu-PcCP NPs can achieve a detection limit of 4.88 μM for the H₂O₂, 4.27 μM for the L-cysteine, and 21.10 μM for the glucose via a cascade catalytic system, which shows comparable detecting sensitivity as that of many earlier reported enzyme-like nanomaterials. Moreover, Cu-PcCP NPs present remarkable resistance to harsh conditions, including high temperature, low pH, and excessive salts. These highly specific π-conjugated copper-phthalocyanine nanoparticles not only overcome the current limitation of polymeric material-based sensors but also provide a new direction for designing next-generation enzyme-like nanomaterial-based colorimetric biosensors.     

Making carbon nanotubes biocompatible and biodegradable

Carbon nanotubes are promising nanomaterials with great potential in the field of nanomedicine for both therapeutic and diagnostic applications. Different approaches have been developed to render this material biocompatible and to modulate any ensuing toxic effects. In the context of medical use, although chemically functionalised carbon nanotubes display reduced toxicity, they are still considered with scepticism due to their perceived non-biodegradability. Recently, it has been demonstrated that functionalised carbon nanotubes can be degraded by oxidative enzymes. This finding is offering a new perspective for the development of carbon nanotubes in medicine. This article highlights recent advances that can act as paradigm-shifts towards the design of biocompatible and biodegradable functionalised carbon nanotubes and allow their translation into the clinic.     

Fluorescent nanoparticles for intracellular sensing: A review

Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy.     

Fluorinated Nanocarbons Cytotoxicity

As the research in nanotechnology progresses, there will eventually be an influx in the number of commercial products containing different types of nanomaterials. This phenomenon might damage our health and environment if the nanomaterials used are found to be toxic and they are released into the waters when the products degrade. In this study, we investigated the cytotoxicity of fluorinated nanocarbons (CXFs), a group of nanomaterials which can find applications in solid lubricants and lithium primary batteries. Our cell viability findings indicated that the toxicological effects induced by the CXF are dependent on the dose, size, shape, and fluorine content of the CXF. In addition, we verified that CXFs have insignificant interactions with the cell viability assays—methylthiazolyldiphenyl‐tetrazolium bromide (MTT) and water‐soluble tetrazolium salt (WST‐8), thus suggesting that the cytotoxicity data obtained are unlikely to be affected by CXF‐induced artifacts and the results will be reliable.     

Biomedical application and hidden toxicity of Zinc oxide nanoparticles

Zinc oxide nanoparticles (ZnO NPs) represent a novel type of metal oxide nanoparticles enabling a new horizon for biomedical applications spanning from diagnosis to treatment. ZnO NPs are extensively used in commercial products such as sunscreens and daily-care products. Apart from that, ZnO NPs are used in food packaging and ointments and as an antimicrobial and antifungal agent. They are extensively used for many biomedical applications noticeably in pharmaceutics and theranostics. Its exceptional optical, electrical, and physiochemical properties, notably its incredible surface chemistry, make ZnO NPs a reliable option for bioimaging, biosensors, antimicrobial action, and drug and gene delivery. The present review covers findings and developments in ZnO NPs research in relation to its application and toxicity mechanism. A special emphasis has been given to the neurotoxic potential of the ZnO NPs and glial cell toxicity. Various factors contributing to the toxic potential of ZnO NPs and cell signaling pathways concerning its toxicity are also discussed. Available data point toward the risk of uncontrollable use of zinc nanoformulation. With increasing use, ZnO NPs pose a severe threat both to the ecosystem and human beings. In a nutshell, the review outlines the current state of the art of ZnO NPs.     

High-performance sensor based on copper oxide nanoparticles for dual detection of phenolic compounds and a pesticide

The development of nanomaterials for use as bio-recognition elements is important in the evolution of biosensing systems. In the present article we present a sensing system based on copper oxide nanoparticles (CuO NPs) for the detection of phenolic compounds and pesticides. This sensor takes advantage of the interactions of CuO NPs with toxic compounds that in turn generate an electrochemical signal related to the concentration of the pollutants.     

Single nanoparticle spectroscopy for real-time in vivo quantitative analysis of transport and toxicity of single nanoparticles in single embryos

Nanomaterials exhibit distinctive physicochemical properties and promise a wide range of applications from nanotechnology to nanomedicine, which raise serious concerns about their potential environmental impacts on ecosystems. Unlike any conventional chemicals, nanomaterials are highly heterogeneous, and their properties can alter over time. These unique characteristics underscore the importance of study of their properties and effects on living organisms in real time at single nanoparticle (NP) resolution. Here we report the development of single-NP plasmonic microscopy and spectroscopy (dark-field optical microscopy and spectroscopy, DFOMS) and ultrasensitive in vivo assay (cleavage-stage zebrafish embryos, critical aquatic species) to study transport and toxicity of single silver nanoparticles (Ag NPs, 95.4 ± 16.0 nm) on embryonic developments. We synthesized and characterized purified and stable (non-aggregation) Ag NPs, determined their sizes and doses (number), and their transport mechanisms and effects on embryonic development in vivo in real time at single-NP resolution. We found that single Ag NPs passively entered the embryos through their chorionic pores via random Brownian diffusion and stayed inside the embryos throughout their entire development (120 h), suggesting that the embryos can bio-concentrate trace NPs from their environment. Our studies show that higher doses and larger sizes of Ag NPs cause higher toxic effects on embryonic development, demonstrating that the embryos can serve as ultrasensitive in vivo assays to screen biocompatibility and toxicity of the NPs and monitor their potential release into aquatic ecosystems.     

Degradation of Methyl Parathion,a common pesticide and fluorescence quenching of Rhodamine B,a carcinogen using β-d glucan stabilized gold nanoparticles

Natural carbohydrate polymer β-d-glucan extracted from Tricholoma crassum (Berk.) Sacc. predominantly linked by β-glycosidic bonds have been used to synthesize gold nanoparticles (Au NPs). As glucan is water soluble, the Au NPs are prepared in water medium, a green solvent. The morphology and characterization of the synthesized Au NPs have been confirmed by various techniques, like TEM, EDX, XRD, UV–Vis and FT-IR spectroscopic studies. The obtained Au NPs exhibits chemosensing property against Methyl Parathion, a group of highly toxic organophosphorous pesticide, extensively used as an agricultural chemical. Degradation of parathion using Au NPs lead to water-soluble products thereby reducing the toxicity of Methyl Parathion by disrupting the thiophosphate-ester linkage. The synthesized Au NPs also act as a good fluorescence quencher of Rhodamine B, a common fluorophore and carcinogenic compound, obeying Stern-Volmer equations. The β-d-glucan capped Au NPs are safe having possible medicinal usage.     

Natural product-likeness score and its application for prioritization of compound libraries

Natural products (NPs) have been optimized in a very long natural selection process for optimal interactions with biological macromolecules. NPs are therefore an excellent source of validated substructures for the design of novel bioactive molecules. Various cheminformatics techniques can provide useful help in analyzing NPs, and the results of such studies may be used with advantage in the drug discovery process. In the present study we describe a method to calculate the natural product-likeness score--a Bayesian measure which allows for the determination of how molecules are similar to the structural space covered by natural products. This score is shown to efficiently separate NPs from synthetic molecules in a cross-validation experiment. Possible applications of the NP-likeness score are discussed and illustrated on several examples including virtual screening, prioritization of compound libraries toward NP-likeness, and design of building blocks for the synthesis of NP-like libraries.     

Understanding nanoparticle cellular entry: A physicochemical perspective

Understanding interactions between nanoparticles (NPs) with biological matter, particularly cells, is becoming increasingly important due to their growing application in medicine and materials, and consequent biological and environmental exposure. For NPs to be utilised to their full potential, it is important to correlate their functional characteristics with their physical properties, which may also be used to predict any adverse cellular responses. A key mechanism for NPs to impart toxicity is to gain cellular entry directly. Many parameters affect the behaviour of nanomaterials in a cellular environment particularly their interactions with cell membranes, including their size, shape and surface chemistry as well as factors such as the cell type, location and external environment (e.g. other surrounding materials, temperature, pH and pressure). Aside from in vitro and in vivo experiments, model cell membrane systems have been used in both computer simulations and physicochemical experiments to elucidate the mechanisms for NP cellular entry. Here we present a brief overview of the effects of NPs physical parameters on their cellular uptake, with focuses on 1) related research using model membrane systems and physicochemical methodologies; and 2) proposed physical mechanisms for NP cellular entrance, with implications to their nanotoxicity. We conclude with a suggestion that the energetic process of NP cellular entry can be evaluated by studying the effects of NPs on lipid mesophase transitions, as the molecular deformations and thus the elastic energy cost are analogous between such transitions and endocytosis. This presents an opportunity for contributions to understanding nanotoxicity from a physicochemical perspective.     

Targeted polymeric therapeutic nanoparticles: design, development and clinical translation

Polymeric materials have been used in a range of pharmaceutical and biotechnology products for more than 40 years. These materials have evolved from their earlier use as biodegradable products such as resorbable sutures, orthopaedic implants, macroscale and microscale drug delivery systems such as microparticles and wafers used as controlled drug release depots, to multifunctional nanoparticles (NPs) capable of targeting, and controlled release of therapeutic and diagnostic agents. These newer generations of targeted and controlled release polymeric NPs are now engineered to navigate the complex in vivo environment, and incorporate functionalities for achieving target specificity, control of drug concentration and exposure kinetics at the tissue, cell, and subcellular levels. Indeed this optimization of drug pharmacology as aided by careful design of multifunctional NPs can lead to improved drug safety and efficacy, and may be complimentary to drug enhancements that are traditionally achieved by medicinal chemistry. In this regard, polymeric NPs have the potential to result in a highly differentiated new class of therapeutics, distinct from the original active drugs used in their composition, and distinct from first generation NPs that largely facilitated drug formulation. A greater flexibility in the design of drug molecules themselves may also be facilitated following their incorporation into NPs, as drug properties (solubility, metabolism, plasma binding, biodistribution, target tissue accumulation) will no longer be constrained to the same extent by drug chemical composition, but also become in-part the function of the physicochemical properties of the NP. The combination of optimally designed drugs with optimally engineered polymeric NPs opens up the possibility of improved clinical outcomes that may not be achievable with the administration of drugs in their conventional form. In this critical review, we aim to provide insights into the design and development of targeted polymeric NPs and to highlight the challenges associated with the engineering of this novel class of therapeutics, including considerations of NP design optimization, development and biophysicochemical properties. Additionally, we highlight some recent examples from the literature, which demonstrate current trends and novel concepts in both the design and utility of targeted polymeric NPs (444 references).     

Egg white as a natural and safe biomaterial for enhanced cancer therapy

The last few decades have witnessed the emergence of a very large variety of engineered nanomaterials. However, it is far from to meet the growing clinical demand. Actually, nature itself is an excellent nanotechnologist, and provides us with a range of wonderful materials, from inorganic particles found in non-life bodies to biofilms, like platelets, erythrocyte membranes, produced by many bacteria or cells. These nanomaterials are entirely natural, and not surprisingly, there is a growing interest in the development of natural nanoproducts. Native components-inspired biomaterials have gained considerable attention owing to their safety and functions. In this study, egg white was developed as drug carrier to load PTX by a green and simple one-pot method, and systematic characterization was completed. The results indicated that PTX@EW NPs possess excellent biocompatibility, enhanced tumor targeting capability, effectively reducing the toxic side effects of PTX. The obviously enhanced antitumor effect further confirmed EW was a highly prospective biomaterial in the nano-carrier industry.