Synthesis of 14C-labelled polystyrene nanoplastics for environmental studies

AbstractAvailable analytical methods cannot detect nanoplastics at environmentally realistic concentrations in complex matrices such as biological tissues. Here, we describe a one-step polymerization method, allowing direct radiolabeling of a sulfonate end-capped nano-sized polystyrene (nPS; proposed as a model nanoplastic particle representing negatively charged nanoplastics). The method, which produces nanoplastics trackable in simulated environmental settings which have already been used to investigate the behavior of a nanoplastic in vivo in a bivalve mollusc, was developed, optimized and successfully applied to synthesis of 14C-labeled nPS of different sizes. In addition to a description of the method of synthesis, we describe the details for quantification, mass balance and recovery of the labelled particles from complex matrices offered by the radiolabelling approach. The radiolabeling approach described here, coupled to use of a highly sensitive autoradiographic method for monitoring nanoplastic body burden and distributions, may provide a valuable procedure for investigating the environmental pathways followed by negatively charged nanoplastics at low predicted environmental concentrations. Whether the behaviour of the synthetic nPS manufactured here, synthesised using a very common inititator, represents that of manufactured nPS found in the environment, remains to be seen.</jats:p

Nanoparticles in feed: progress and prospects in poultry research

Abstract not availableSheeana Gangadoo, Dragana Stanley, Robert J. Hughes, Robert J. Moore, James Chapma

The synthesis and characterisation of highly stable and reproducible selenium nanoparticles

This paper describes a simple and reproducible solution phase synthesis approach for selenium nanoparticles by reducing selenium tetrachloride in the presence of ascorbic acid. An optimization study with poly (sodium 4-styrenesulfonate) produced stable and spherical narrowly size distributed nanoparticles (46 nm) which are considered highly monodisperse. The presence of selenium nanoparticles was confirmed by UV-visible spectroscopy for surface plasmon resonance (262 nm), elemental dispersive spectroscopy (11 KeV and 12.5 KeV) and size ranges characterized by dynamic light scattering (PDI = 0.04, the ​size range of optimized nanoparticles = 35 nm to 75 nm), and visualized using scanning and transmission electron microscopy

The synthesis and characterisation of highly stable and reproducible selenium nanoparticles

This paper describes a simple and reproducible solution phase synthesis approach for selenium nanoparticles by reducing selenium tetrachloride in the presence of ascorbic acid. An optimization study with poly (sodium 4-styrenesulfonate) produced stable and spherical narrowly size distributed nanoparticles (46 nm) which are considered highly monodisperse. The presence of selenium nanoparticles was confirmed by UV-visible spectroscopy for surface plasmon resonance (262 nm), elemental dispersive spectroscopy (11 KeV and 12.5 KeV) and size ranges characterized by dynamic light scattering (PDI = 0.04, size range of optimized nanoparticles = 35 nm to 75 nm), and visualized using scanning and transmission electron microscopy

Nanoparticles of selenium as high bioavailable and non-toxic supplement alternatives for broiler chickens

Published online: 27 February 2020Selenium is commonly used in the poultry industry as an additive in broiler feed to improve immunity and overall health. The selenium comes in different forms, inorganic and organic selenium, as sodium selenite and selenomethionine, respectively. This study proposes the use of nanoparticles of selenium (nanoSe) for improved delivery and absorption of the trace element while causing no toxicity. Previous studies have shown the success in utilizing nanoSe in broiler feed, with increased absorption and diffusion of material into organs and tissues, and increased antioxidant capacity. However, the mechanism of nanoSe conversion remains unknown, and the gut microbiota is believed to play a significant role in the process. The use of inorganic selenium in poultry feed demonstrated a lower bioavailability in breast (P ≤ 0.01) and duodenum tissue (P ≤ 0.05), and increased accumulation in organs involved in detoxification processes as compared to organic selenium and selenium nanoparticle supplementation. Histopathological analysis showed that nanoSe did not cause any damaging effects to the tissues analysed, revealing intact epithelial cells in the digestive system and neuronal bodies in brain tissue. The results indicate that nanoparticles of selenium operate a similar way to organic selenium and could potentially be used in poultry feed as a trace element additive.Sheeana Gangadoo, Ivan Dinev, Nicky-Lee Willson, Robert J. Moore, James Chapman and Dragana Stanle

In vitro growth of gut microbiota with selenium nanoparticles

The application of nanoparticles rose steeply in the last decade, where they have become a common ingredient used in processed human food, improving food properties such as shelf life and appearance. Nanoparticles have also attracted considerable interest to the livestock industry, due to their efficacy in intestinal pathogen control, with the regulatory and consumer driven push for the removal of antibiotic growth promoters. The influence of selenium (Se) nanoparticles was investigated on a diverse and mature broiler caecal microbiota using in vitro culturing and 16S rRNA gene sequencing methods for microbiota characterisation. Caecal microbiota was collected from 4 traditionally grown heritage roosters and grown for 48 h, in the presence and absence of Se nanoparticles, with 2 technical replicates each. The effect of rooster as a biological variable strongly overpowered the effects of nano-Se in the media, resulting in moderate effects on the structure and diversity of the caecal microbial community. However the nanoparticles showed a significant reduction (P &lt; 0.05) in the abundance of an emerging poultry pathogen, Enterococcus cecorum identical operational taxonomic units (OTU), which could be of notable interest in poultry production for targeted E. cecorum control without significant disturbance to the total microbial community

The synthesis and characterisation of highly stable and reproducible selenium nanoparticles

This paper describes a simple and reproducible solution phase synthesis approach for selenium nanoparticles by reducing selenium tetrachloride in the presence of ascorbic acid. An optimization study with poly (sodium 4-styrenesulfonate) produced stable and spherical narrowly size distributed nanoparticles (46 nm) which are considered highly monodisperse. The presence of selenium nanoparticles was confirmed by UV-visible spectroscopy for surface plasmon resonance (262 nm), elemental dispersive spectroscopy (11 KeV and 12.5 KeV) and size ranges characterized by dynamic light scattering (PDI = 0.04, size range of optimized nanoparticles = 35 nm to 75 nm), and visualized using scanning and transmission electron microscopy

Selenium nanoparticles in poultry feed modify gut microbiota and increase abundance of Faecalibacterium prausnitzii

The poultry industry aims to improve productivity while maintaining the health and welfare of flocks. Pathogen control has been achieved through biosecurity, vaccinations and the use of antibiotics. However, the emergence of antibiotic resistance, in animal and human pathogens, has prompted researchers and chicken growers alike to seek alternative approaches. The use of new and emerging approaches to combat pathogen activity including nanotechnology, in particular, silver nanoparticles (NPs), has been found to not only eradicate pathogenic bacteria but also include issues of toxicity and bioaccumulation effects. Other novel metal nanoparticles could provide this pathogen reducing property with a more tailored and biocompatible nanomaterial for the model used, something our study represents. This study investigated the benefits of nanomaterial delivery mechanisms coupled with important health constituents using selenium as a biocompatible metal to minimise toxicity properties. Selenium NPs were compared to two common forms of bulk selenium macronutrients already used in the poultry industry. An intermediate concentration of selenium nanoparticles (0.9 mg/kg) demonstrated the best performance, improving the gut health by increasing the abundance of beneficial bacteria, such as Lactobacillus and Faecalibacterium, and short-chain fatty acids (SCFAs), in particular butyric acid. SCFAs are metabolites produced by the intestinal tract and are used as an energy source for colonic cells and other important bodily functions. Selenium nanoparticles had no significant effect on live weight gain or abundance of potentially pathogenic bacteria

A review of methods for the detection of pathogenic microorganisms.

The testing and rapid detection of pathogenic organisms is a crucial protocol in the prevention and identification of crises related to health, safety and wellbeing. Pathogen detection has become one of the most challenging aspects in the food and water industries, because of the rapid spread of waterborne and foodborne diseases in the community and at significant costs. With the prospect of inevitable population growth and an influx of tourism to certain water bodies testing will become a requirement to control and prevent possible outbreaks of potentially fatal illnesses. The legislation is already particularly rigorous in the food industry, where failure to detect pathogenic materials represents a catastrophic event, particularly for the elderly, very young or immune-compromised population types. In spite of the need and requirement for rapid analytical testing, conventional and standard bacterial detection assays may take up to seven days to yield a result. Given the advent of new technologies, biosensors, chemical knowledge and miniaturisation of instrumentation this timescale is not acceptable. This review represents an opportunity to fill a knowledge gap for an extremely important research area; discussing the main techniques, biology, chemistry, miniaturisation, sensing and the emerging state-of-the-art research and developments for detection of pathogens in food, water, blood and faecal samples