Comparison of Metal-Based Nanoparticles and Nanowires: Solubility, Reactivity, Bioavailability and Cellular Toxicity

While the toxicity of metal-based nanoparticles (NP) has been investigated in an increasing number of studies, little is known about metal-based fibrous materials, so-called nanowires (NWs). Within the present study, the physico-chemical properties of particulate and fibrous nanomaterials based on Cu, CuO, Ni, and Ag as well as TiO2 and CeO2 NP were characterized and compared with respect to abiotic metal ion release in different physiologically relevant media as well as acellular reactivity. While none of the materials was soluble at neutral pH in artificial alveolar fluid (AAF), Cu, CuO, and Ni-based materials displayed distinct dissolution under the acidic conditions found in artificial lysosomal fluids (ALF and PSF). Subsequently, four different cell lines were applied to compare cytotoxicity as well as intracellular metal ion release in the cytoplasm and nucleus. Both cytotoxicity and bioavailability reflected the acellular dissolution rates in physiological lysosomal media (pH 4.5); only Ag-based materials showed no or very low acellular solubility, but pronounced intracellular bioavailability and cytotoxicity, leading to particularly high concentrations in the nucleus. In conclusion, in spite of some quantitative differences, the intracellular bioavailability as well as toxicity is mostly driven by the respective metal and is less modulated by the shape of the respective NP or NW.

Copper Nanoparticles: Synthesis and Characterization, Physiology, Toxicity and Antimicrobial Applications

Metallic nanoparticles are a new class of materials with applications in medicine, pharmaceutical and agriculture. Using biological, chemical and physical approaches, nanoparticles with amazing properties are obtained. Copper is one of the most-found elements and plays an important part in the normal functioning of organisms. Coper nanoparticles have superior antibacterial properties when comparing them to present day antibiotics. Moreover, apart from their antibacterial role, antifungal, antiviral and anticancer properties have been described. Although the mechanism of actions is not completely understood, copper nanoparticles can become a viable alternative in fighting multi-resistant bacteria strains. We hereby review the already existing data on copper nanoparticle synthesis, effects and mechanisms of action as well as toxicity.

Lentiviral Vectors Expressing Chimeric NEDD4 Ubiquitin Ligases: An Innovative Approach for Interfering with Alpha-Synuclein Accumulation

One of the main pathological features of Parkinson’s disease (PD) is a diffuse accumulation of alpha-synuclein (aS) aggregates in neurons. The NEDD4 E3 Ub ligase promotes aS degradation by the endosomal–lysosomal route. Interestingly, NEDD4, as well as being a small molecule able to trigger its functions, is protective against human aS toxicity in evolutionary distant models. While pharmacological activation of E3 enzymes is not easy to achieve, their flexibility and the lack of “consensus” motifs for Ub-conjugation allow the development of engineered Ub-ligases, able to target proteins of interest. We developed lentiviral vectors, encoding well-characterized anti-human aS scFvs fused in frame to the NEDD4 catalytic domain (ubiquibodies), in order to target ubiquitinate aS. We demonstrate that, while all generated ubiquibodies bind to and ubiquitinate aS, the one directed against the non-amyloid component (NAC) of aS (Nac32HECT) affects aS’s intracellular levels. Furthermore, Nac32HECT expression partially rescues aS’s overexpression or mutation toxicity in neural stem cells. Overall, our data suggest that ubiquibodies, and Nac32HECT in particular, represent a valid platform for interfering with the effects of aS’s accumulation and aggregation in neurons.

Application of sewage sludge combined with thiourea improves the growth and yield attributes of wheat (Triticum aestivum L.) genotypes under arsenic-contaminated soil

Arsenic (As) contamination is a serious threat to agriculture and human health worldwide. It can adversely affect the growth attributes of food crops. On the other hand, using thiourea (TU) to ameliorate As stress is an economically consistent approach. However, there is a knowledge gap regarding the combined use of TU and Sewage sludge (SS). SS is considered important, unutilized biomass. It can be used as a fertilizer that has high organic matter and nutrients. Therefore, the current study was performed to evaluate TU and SS sole and combined responses under As toxicity on two wheat genotypes (Markaz 19 and Ujala 16). There were four treatments control (As 50 mg kg-1), SS (30 g kg−1)+TU (6.5 mM)+As, TU+As and SS+As applied with four replications. Results revealed that SS+TU performed significantly better over SS, TU and control for improvement in root and shoot fresh and dry weight of wheat varieties Markaz 19 and Ujala 16 under As toxicity. A significant decrease in POD, SOD and APX of Markaz 19 and Ujala 16 also validated the effective functioning of SS+TU over control. The maximum increase of 71 and 77% was noted in phosphorus, where SS+TU was applied over control in Markaz 19 and Ujala 16, respectively. In conclusion, SS+TU is a better approach than the sole application of SS and TU under As contamination for improvement in wheat growth attributes. More investigations are recommended at the field level under different As contamination and agro-climatic zones to declare SS+TU an effective amendment to mitigate As toxicity in wheat.

Assessing Detergent Residuals for Reusable Device Cleaning Validations

Cleaning chemistries are detergent-based formulations that are used during the processing of reusable medical devices. Manufacturers are responsible for demonstrating the safety of cleaning formulations when they are used during a device processing cycle, including the risk of device-associated cytotoxicity over the concentration ranges for recommended use and rinsing during cleaning. However, no regulation currently exists requiring manufacturers to demonstrate such safety. Although manufacturers' safety data sheets (SDSs) provide information on the safe use of chemicals for users, this information may not provide sufficient detail to determine the risks of residual chemicals on device surfaces. SDSs are not required to contain a comprehensive list of chemicals used, only those of risk to the user. They should be supplemented with information on the correct concentrations that should be used for cleaning, as well as instructions on the rinsing required to reduce the levels of chemicals to safe (nontoxic) levels prior to further processing. Supporting data, such as toxicity profiles or cytotoxicity data that support the instructions for use, would provide medical device manufacturers and healthcare personnel with the necessary information to make informed decisions about selection and correct use of detergents. In the current work, cytotoxicity profiles for eight commonly used cleaning formulations available internationally were studied. Although all of these products are indicated for use in the cleaning of reusable medical devices, results vary across the serial dilution curves and are not consistent among detergent types. The information presented here can be leveraged by both medical device manufacturers and processing department personnel to properly assess residual detergent risks during processing. This work also serves as a call to cleaning formulation manufacturers to provide this information for all chemistries.

Advances in Nanotechnology towards Development of Silver Nanoparticle-Based Wound-Healing Agents

Since antiquity, silver-based therapies have been used in wound healing, wound care and management of infections to provide adequate healing. These therapies are associated with certain limitations, such as toxicity, skin discolouration and bacterial resistance, which have limited their use. As a result, new and innovative wound therapies, or strategies to improve the existing therapies, are sought after. Silver nanoparticles (AgNPs) have shown the potential to circumvent the limitations associated with conventional silver-based therapies as described above. AgNPs are effective against a broad spectrum of microorganisms and are less toxic, effective at lower concentrations and produce no skin discolouration. Furthermore, AgNPs can be decorated or coupled with other healing-promoting materials to provide optimum healing. This review details the history and impact of silver-based therapies leading up to AgNPs and AgNP-based nanoformulations in wound healing. It also highlights the properties of AgNPs that aid in wound healing and that make them superior to conventional silver-based wound treatment therapies.

Influence of Dietary Compounds on Arsenic Metabolism and Toxicity. Part II—Human Studies

Exposure to various forms of arsenic (As), the source of which may be environmental as well as occupational exposure, is associated with many adverse health effects. Therefore, methods to reduce the adverse effects of As on the human body are being sought. Research in this area focuses, among other topics, on the dietary compounds that are involved in the metabolism of this element. Therefore, the aim of this review was to analyze the influence of methionine, betaine, choline, folic acid, vitamin B2, B6, B12 and zinc on the efficiency of inorganic As (iAs) metabolism and the reduction in the severity of the whole spectrum of disorders related to As exposure. In this review, which included 62 original papers (human studies) we present the current knowledge in the area. In human studies, these compounds (methionine, choline, folic acid, vitamin B2, B6, B12 and zinc) may increase iAs metabolism and reduce toxicity, whereas their deficiency may impair iAs metabolism and increase As toxicity. Taking into account the results of studies conducted in populations exposed to As, it is reasonable to carry out prophylactic activities. In particular nutritional education seems to be important and should be focused on informing people that an adequate intake of those dietary compounds potentially has a modulating effect on iAs metabolism, thus, reducing its adverse effects on the body.

The controversies of genetically modified food

The increasing use of genetically modified (GM) foods and feeds attracts the interest of media and public, causing great concern among consumers about the consequences of their consumption. The issues of concern are mainly focused on the impact on consumer health and the repercussions on the environment. The biggest fears are the possible negative consequences on human and animal health, which encompass allergic reactions, side effects such as toxicity, damage to individual organs, gene transfer and differences in nutritional value. Consumers are unsure and confused as to whether consuming GM foods is harmful to their health or not. According to a Pew Research Center survey conducted between October 2019 and March 2020, 48% of respondents said GM foods are harmful, 13% responded GM foods are safe, while 37% of respondents could not express their opinion due to lack of knowledge about it. Numerous studies have been undertaken to examine the effects that GM foods and feeds exert on humans and animals. The results differ in many ways that issue numerous questions. In this paper, we will try addressing questions that concern the public, as well as the activities and measures that science and competent institutions are taking to confront them.