Nanomaterial-induced toxicity in pathophysiological models representative of individuals with pre-existing medical conditions

Microplastic-induced hepatic adverse effects evaluated in advanced quadruple cell human primary models following three weeks of repeated exposure

Nano and microplastics are defined as particles smaller than 100 nm and 5 mm respectively. The widespread production and use of plastics in everyday life has resulted in significant accumulation of plastic debris in the environment. Over the last two decades there are increased concerns regarding the potential entry and accumulation of plastics in the human body with ingestion being one of the most important routes of exposure. However, the magnitude and nature of potential toxic effects of plastic exposure to human health is not yet fully understood. The liver is the body's principal detoxification organ and critically to this study recognized as the main accumulation site for particulates. In this study as the first of its kind the health impacts of long term low repeated polystyrene microplastics (1 and 5 μm) exposure was investigated in a functionally active 3D liver microtissue model, composed of primary human hepatocytes, Kupffer cells, sinusoidal endothelial cells and hepatic stellate cells. The highlight from the data includes microplastic-induced dose (3.125-25 μg/ml) and time dependent (up to 504 h) increase in cell death and inflammation manifested by enhanced release of IL6, IL8 and TNF-α. The exposure to repeated dosing of the plastics also resulted in notable pathology manifested as aberrant tissue architecture, such as dilated bile canaliculi and large lipid droplets inside the hepatic cells. This toxicity matched extremely well to the accumulation of the materials with the cells of microtissue predominately in the organ macrophages. This study highlights the real issue and danger of microplastic exposure with potential for long-term accumulation and adverse effects of non-biodegradable plastics within the liver.

Opportunities and Challenges for Inhalable Nanomedicine Formulations in Respiratory Diseases: A Review

Lungs experience frequent interactions with the external environment and have an abundant supply of blood; therefore, they are susceptible to invasion by pathogenic microorganisms and tumor cells. However, the limited pharmacokinetics of conventional drugs in the lungs poses a clinical challenge. The emergence of different nano-formulations has been facilitated by advancements in nanotechnology. Inhaled nanomedicines exhibit better targeting and prolonged therapeutic effects. Although nano-formulations have great potential, they still present several unknown risks. Herein, we review the (1) physiological anatomy of the lungs and their biological barriers, (2) pharmacokinetics and toxicology of nanomaterial formulations in the lungs; (3) current nanomaterials that can be applied to the respiratory system and related design strategies, and (4) current applications of inhaled nanomaterials in treating respiratory disorders, vaccine design, and imaging detection based on the characteristics of different nanomaterials. Finally, (5) we analyze and summarize the challenges and prospects of nanomaterials for respiratory disease applications. We believe that nanomaterials, particularly inhaled nano-formulations, have excellent prospects for application in respiratory diseases. However, we emphasize that the simultaneous toxic side effects of biological nanomaterials must be considered during the application of these emerging medicines. This study aims to offer comprehensive guidelines and valuable insights for conducting research on nanomaterials in the domain of the respiratory system.

Buthionine sulfoximine and chemoresistance in cancer treatments: a systematic review with meta-analysis of preclinical studies

Buthionine sulfoximine (BSO) is a synthetic amino acid that blocks the biosynthesis of reduced glutathione (GSH), an endogenous antioxidant cellular component present in tumor cells. GSH levels have been associated with tumor cell resistance to chemotherapeutic drugs and platinum compounds. Consequently, by depleting GSH, BSO enhances the cytotoxicity of chemotherapeutic agents in drug-resistant tumors. Therefore, the aim of this study was to conduct a systematic review with meta-analysis of preclinical studies utilizing BSO in cancer treatments. The systematic search was carried out using the following databases: PubMed, Web of Science, Scopus, and EMBASE up until March 20, 2023, in order to collect preclinical studies that evaluated BSO, alone or in association, as a strategy for antineoplastic therapy. One hundred nine investigations were found to assess the cytotoxic potential of BSO alone or in combination with other compounds. Twenty-one of these met the criteria for performing the meta-analysis. The evidence gathered indicated that BSO alone exhibits cytotoxic activity. However, this compound is generally used in combination with other antineoplastic strategies, mainly chemotherapy ones, to improve cytotoxicity to carcinogenic cells and treatment efficacy. Finally, this review provides important considerations regarding BSO use in cancer treatment conditions, which might optimize future studies as a potential adjuvant antineoplastic therapeutic tool.

Spring water quality monitoring using multiple bioindicators from multiple collection sites

The aim of this study was to examine the water quality of the Extrema River spring in a Brazilian Cerrado area. Three collection sites (P1 - P3) were sampled in the dry and rainy seasons, which are close to industries from different sectors. In the physicochemical analysis, a decrease in dissolved oxygen levels (<5 mg/L) and pH (< 6) at P3 was detected. An increase in heterotrophic bacteria count was recorded at all sites (> 500 colonies/ml). In ecotoxicological analyses, P2 and P3 exhibited toxicity using Vibrio fischeri (> 20%). In evaluating toxicity, the reduction in seed germination was significant utilizing Lactuca sativa at all locations and with Allium cepa only at P2; rootlet length was decreased at P3 on L. sativa and at all sites with A. cepa. In contrast, loss of membrane integrity and mitochondrial function of meristems was adversely affected at all locations using both L. sativa and A. cepa assays. Principal components analysis (PCA) approach indicated that seasonality apparently did not markedly interfere with the obtained data, but it is important to include more collection locations to be evaluated with multiple bioindicators in the spring region. Our data indicate the urgent need for more rigorous programs to monitor the discharge of effluents into water springs.

Toxicity and Mechanisms of Engineered Nanoparticles in Animals with Established Allergic Asthma

Asthma is a chronic respiratory disease that is highly sensitive to environmental pollutants, including engineered nanoparticles (NPs). Exposure to NPs has become a growing concern for human health, especially for susceptible populations. Toxicological studies have demonstrated strong associations between ubiquitous NPs and allergic asthma. In this review, we analyze articles that focus on adverse health effects induced by NPs in animal models of allergic asthma to highlight their critical role in asthma. We also integrate potential mechanisms that could stimulate and aggravate asthma by NPs. The toxic effects of NPs are influenced by their physicochemical properties, exposure dose, duration, route, as well as the exposure order between NPs and allergens. The toxic mechanisms involve oxidative stress, various inflammasomes, antigen presenting cells, immune cells, and signaling pathways. We suggest that future research should concentrate on establishing standardized models, exploring mechanistic insights at the molecular level, assessing the combined effects of binary exposures, and determining safe exposure levels of NPs. This work provides concrete evidence of the hazards posed by NPs in animals with compromised respiratory health and supports the modifying role of NPs exposure in allergic asthma.

Assessing the in vitro toxicity of airborne (nano)particles to the human respiratory system: from basic to advanced models

Several studies have been conducted to address the potential adverse health risks attributed to exposure to nanoscale materials. While in vivo studies are fundamental for identifying the relationship between dose and occurrence of adverse effects, in vitro model systems provide important information regarding the mechanism(s) of action at the molecular level. With a special focus on exposure to inhaled (nano)particulate material toxicity assessment, this review provides an overview of the available human respiratory models and exposure systems for in vitro testing, advantages, limitations, and existing investigations using models of different complexity. A brief overview of the human respiratory system, pathway and fate of inhaled (nano)particles is also presented.