Combinatory Effects of Cerium Dioxide Nanoparticles and Acetaminophen on the Liver-A Case Study of Low-Dose Interactions in Human HuH-7 Cells

Lipidomics Investigation Reveals the Reversibility of Hepatic Injury by Silica Nanoparticles in Rats After a 6-Week Recovery Duration

Given the inevitable human exposure owing to its increasing production and utilization, the comprehensive safety evaluation of silica nanoparticles (SiNPs) has sparked concerns. Substantial evidence indicated liver damage by inhaled SiNPs. Notwithstanding, few reports focused on the persistence or reversibility of hepatic injuries, and the intricate molecular mechanisms involved remain limited. Here, rats are intratracheally instilled with SiNPs in two regimens (a 3-month exposure and a subsequent 6-week recovery after terminating SiNPs administration) to assess the hepatic effects. Nontargeted lipidomics revealed alterations in lipid metabolites as a contributor to the hepatic response and recovery effects of SiNPs. In line with the functional analysis of differential lipid metabolites, SiNPs activated oxidative stress, and induced lipid peroxidation and lipid deposition in the liver, as evidenced by the elevated hepatic levels of ROS, MDA, TC, and TG. Of note, these indicators showed great improvements after a 6-week recovery, even returning to the control levels. According to the correlation, ROC curve, and SEM analysis, 11 lipids identified as potential regulatory molecules for ameliorating liver injury by SiNPs. Collectively, the work first revealed the reversibility of SiNP-elicited hepatotoxicity from the perspective of lipidomics and offered valuable laboratory evidence and therapeutic strategy to facilitate nanosafety.

Epigenetic inhibitors and their role in cancer therapy

Epigenetic modifications to DNA are crucial for normal cellular and biological functioning. DNA methylation, histone modifications, and chromatin remodeling are the most common epigenetic mechanisms. These changes are heritable but still reversible. The aberrant epigenetic alterations, such as DNA methylation, histone modification, and non-coding RNA (ncRNA)-mediated gene regulation, play an essential role in developing various human diseases, including cancer. Recent studies show that synthetic and dietary epigenetic inhibitors attenuate the abnormal epigenetic modifications in cancer cells and therefore have strong potential for cancer treatment. In this chapter, we have highlighted various types of epigenetic modifications, their mechanism, and as drug targets for epigenetic therapy.

The toxicity of nanoparticles and their interaction with cells: an in vitro metabolomic perspective

Nowadays, nanomaterials (NMs) are widely present in daily life due to their significant benefits, as demonstrated by their application in many fields such as biomedicine, engineering, food, cosmetics, sensing, and energy. However, the increasing production of NMs multiplies the chances of their release into the surrounding environment, making human exposure to NMs inevitable. Currently, nanotoxicology is a crucial field, which focuses on studying the toxicity of NMs. The toxicity or effects of nanoparticles (NPs) on the environment and humans can be preliminary assessed in vitro using cell models. However, the conventional cytotoxicity assays, such as the MTT assay, have some drawbacks including the possibility of interference with the studied NPs. Therefore, it is necessary to employ more advanced techniques that provide high throughput analysis and avoid interferences. In this case, metabolomics is one of the most powerful bioanalytical strategies to assess the toxicity of different materials. By measuring the metabolic change upon the introduction of a stimulus, this technique can reveal the molecular information of the toxicity induced by NPs. This provides the opportunity to design novel and efficient nanodrugs and minimizes the risks of NPs used in industry and other fields. Initially, this review summarizes the ways that NPs and cells interact and the NP parameters that play a role in this interaction, and then the assessment of these interactions using conventional assays and the challenges encountered are discussed. Subsequently, in the main part, we introduce the recent studies employing metabolomics for the assessment of these interactions in vitro.

The assessment of the potential hepatotoxicity of new drugs by in vitro metabolomics

Drug hepatotoxicity assessment is a relevant issue both in the course of drug development as well as in the post marketing phase. The use of human relevant in vitro models in combination with powerful analytical methods (metabolomic analysis) is a promising approach to anticipate, as well as to understand and investigate the effects and mechanisms of drug hepatotoxicity in man. The metabolic profile analysis of biological liver models treated with hepatotoxins, as compared to that of those treated with non-hepatotoxic compounds, provides useful information for identifying disturbed cellular metabolic reactions, pathways, and networks. This can later be used to anticipate, as well to assess, the potential hepatotoxicity of new compounds. However, the applicability of the metabolomic analysis to assess the hepatotoxicity of drugs is complex and requires careful and systematic work, precise controls, wise data preprocessing and appropriate biological interpretation to make meaningful interpretations and/or predictions of drug hepatotoxicity. This review provides an updated look at recent in vitro studies which used principally mass spectrometry-based metabolomics to evaluate the hepatotoxicity of drugs. It also analyzes the principal drawbacks that still limit its general applicability in safety assessment screenings. We discuss the analytical workflow, essential factors that need to be considered and suggestions to overcome these drawbacks, as well as recent advancements made in this rapidly growing field of research.

Development of Copper Nanoparticle Conjugated Chitosan Microparticle as a Stable Source of 2nm Copper Nanoparticle Effective against Methicillin- resistant Staphylococcus aureus

BACKGROUND

Copper nanoparticle (CuNP) has well-established antimicrobial activity. Instability in an aqueous medium due to aggregation into larger particles, conversion into metal ions, and oxidation into metal oxides are the major limitations of its practical use against bacterial infections.

OBJECTIVE

Development of CuNP Conjugated Chitosan Microparticles as a reservoir that will release CuNP effective against notorious bacteria like Methicillin-resistant Staphylococcus aureus.

METHODS

CuNP conjugated chitosan microparticles (CNCCM) were synthesized using a simple twostep process. In the first step, a solution of chitosan in 2% (w/v) ascorbic acid was added dropwise in copper sulphate solution to prepare Cu ion conjugated chitosan beads. In the second step, these beads were soaked in sodium hydroxide solution to get the CNCCM. The dried CNCCM were characterized thoroughly for surface conjugation of CuNP, and the release of CuNP in a suitable medium. The physicochemical properties of release CuNP were further verified with the in silico modelled CuNP. The Antimicrobial and antibiofilm activities of released CuNp were evaluated against methicillin-resistant Staphylococcus aureus (MRSA).

RESULTS

2% (w/v) ascorbic acid solution (pH 3.5) was the optimum medium for the release of ~2 nm CuNP from CNCCM. The CuNP had an optical band gap of ~ 2 eV. It inhibited the cell wall synthesis of MRSA. The minimum inhibitory concentration was 200 nM. At 100 nM dose, the CuNP caused ~73% reduction in biofilm development after 24 h of growth. The cytotoxic effect of CuNP on the human cell line (HEK 293) was significantly less than that on MRSA. The 48 h IC₅₀ value against HEK 293 was 3.45-fold higher than the MIC value against MRSA after 24 h treatment.

CONCLUSION

CuNP Conjugated Chitosan Microparticle has been developed. It works as a stable reservoir of ~2 nm CuNP. The CuNP is released in an aqueous medium containing 2% (w/v) ascorbic acid (pH 3.5). The released CuNP has a bacteriostatic effect against MRSA at a concentration safe for human cells.

ZnO/CeO2 Nanocomposites: Metal-Organic Framework-Mediated Synthesis, Characterization, and Estimation of Cellular Toxicity toward Liver Cancer Cells

The Zinc-doped cerium oxide nanocomposite (ZnO/CeO₂ NC) was synthesized using a metal-organic framework as a precursor through the combustion method. It was characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), field emission electron microscopy (FESEM), energy dispersive analysis (EDX), transmission electron microscopy (TEM), dynamic light scattering (DLS), and ξ-potential. The PXRD demonstrated the successful synthesis of ZnO/CeO₂ NC with a crystallite size of 31.9 nm. FESEM and TEM images displayed hexagonal and spherical morphologies, and the solid-phase size was 65.03 ± 30.86 nm for ZnO/CeO₂ NCs. DLS, TEM, and FESEM showed that the NCs have a high tendency for agglomeration/aggregation in both aqueous media and solid phase. The anticancer attributes of ZnO/CeO₂ NC were investigated against Liver cancer cells (HepG2), which showed inhibition of cancer cell growth on a concentration-dependent gradient. The cell toxicity effects of ZnO/CeO₂ nanocomposites were also studied toward NIH-3T3, in which the data displayed the lower toxicity of NC compared to the HepG2 cell line.

Genotoxic hazard assessment of cerium oxide and magnesium oxide nanoparticles in Drosophila

The use of metal oxide nanoparticles (NPs) is steadily spreading, leading to increased environmental exposures to many organisms, including humans. To improve our knowledge of this potential hazard, we have evaluated the genotoxic risk of cerium oxide (CeO₂NPs) and magnesium oxide (MgONPs) nanoparticle exposures using Drosophila as an in vivo assay model. In this study, two well-known assays, such as the wing somatic mutation and recombination test (wing-spot assay) and the single-cell gel electrophoresis test (comet assay) were used. As a novelty, and for the first time, changes in the expression levels of a wide panel of DNA repair genes were also evaluated. Our results indicate that none of the concentrations of CeO₂NPs increased the total spot frequency in the wing-spot assay, while induction was observed at the highest dose of MgONPs. Regarding the comet assay, both tested NPs were unable to induce single DNA strand breaks or oxidative damage in DNA bases. Nevertheless, exposure to CeO₂NPs induced significant increases in the expression levels of the Mlh1 and Brca2 genes, which are involved in the double-strand break repair pathway, together with a decrease in the expression levels of the MCPH1 and Rad51D genes. Regarding the effects of MgONPs exposure, the expression levels of the Ercc1, Brca2, Rad1, mu2, and stg genes were significantly increased, while Mlh1 and MCPH1 genes were decreased. Our results show the usefulness of our approach in detecting mild genotoxic effects by evaluating changes in the expression of a panel of genes involved in DNA repair pathways.

The use of cerium oxide nanoparticles in liver disorders: A double-sided coin?

Being recognized as the first antioxidant nanoparticles (NPs) proposed for medicine, cerium oxide nanoparticles (CeO₂ NPs) have recently gained tremendous attention for their vast biomedical applications. Nevertheless, inconsistent reports of either medical benefits or toxicity have created an atmosphere of uncertainty hindering their clinical utilization. Like other nanoparticles advocated as a promising protective/therapeutic option, CeO₂ NPs are sometimes questioned as a health threat. As CeO₂ NPs tend to accumulate in the liver after intravenous injection, liver is known to represent the key tissue to test for their therapeutic/toxicological effects. However, more research evidence is still needed before any conclusions can be elicited about the mechanisms by which CeO₂ NPs could be harmful or protective/therapeutic to the liver tissue. A proper understanding of such discrepancies is warranted to plan for further modifications to mitigate any side effects. Therefore, in this MiniReview, we tried to demonstrate the two sides of the same coin, CeO₂ NPs, within the liver context. As well, we highlighted a few promising strategies by which the negatives of CeO₂ NPs could be diminished while enhancing all the positives.