Toxicity of different forms of graphene in a chicken embryo model

Nanoparticles Mediated the Diagnosis and Therapy of Glioblastoma: Bypass or Cross the Blood-Brain Barrier

Glioblastoma is one of the most aggressive central nervous system malignancies with high morbidity and mortality. Current clinical approaches, including surgical resection, radiotherapy, and chemotherapy, are limited by the difficulty of targeting brain lesions accurately, leading to disease recurrence and fatal outcomes. The lack of effective treatments has prompted researchers to continuously explore novel therapeutic strategies. In recent years, nanomedicine has made remarkable progress and expanded its application in brain drug delivery, providing a new treatment for brain tumors. Against this background, this article reviews the application and progress of nanomedicine delivery systems in brain tumors. In this paper, the mechanism of nanomaterials crossing the blood-brain barrier is summarized. Furthermore, the specific application of nanotechnology in glioblastoma is discussed in depth.

Reproductive and Developmental Nanotoxicity of Carbon Nanoparticles

The presented review aims to summarize the knowledge regarding the reproductive and developmental toxicity of different types of carbon nanoparticles, such as graphene, graphene oxide, multi- and single-walled nanotubes, fullerenes, and nanodiamonds. Carbon nanoparticles have unique chemical and physical properties that make them an excellent material that can be applied in many fields of human activity, including industry, food processing, the pharmaceutical industry, or medicine. Although it has a high degree of biocompatibility, possible toxic effects on different tissue types must also be taken into account. Carbon nanoparticles are known to be toxic to the respiratory, cardiovascular, nervous, digestive system, etc., and, according to current studies, they also have a negative effect on reproduction and offspring development.

Use of Chicken Embryo Model in Toxicity Studies of Endocrine-Disrupting Chemicals and Nanoparticles

Lab animals such as mice and rats are widely used in toxicity research of food additive and pharmaceutics, despite the well-recognized research limitation such as the inability to simulate human neurological diseases, faster absorption of chemicals, big variations among species, and high cost when using a large number of animals. The Society of Toxicology's guidance now focuses on minimizing discomfort and distress of lab animals, finding alternative ways to reduce animal number, replacing animals with in vitro models, and complying to the animal welfare policies. The chicken embryonic model can be a better alternative to mice and rats because of its abundant availability and cost-effectiveness. It can be studied in both laboratory and natural environment, with easy manipulation in ovo or in vivo. The objective of this review paper is to evaluate the use of chicken embryonic model in toxicity evaluation for endocrine-disrupting chemicals (EDCs) and nanoparticles (NPs) by different end points to determine more comprehensive toxic responses. The end points include chicken embryonic mortality and hatchability, developmental malformation analysis, hormonal imbalance, physiological changes in endocrine organs, and antiangiogenesis. Major research methodologies using chicken embryos are also summarized to demonstrate their versatile practice and valuable application in modern toxicity evaluation of EDCs and NPs.

Effect of Muscle Extract and Graphene Oxide on Muscle Structure of Chicken Embryos

Simple Summary

Genetic selection of broilers increased muscle growth; however, very fast growth can lead to pathological conditions caused by the deficiency of nutrients. The number of muscle cells is mainly formed during the embryonic period, and consequently, in ovo supplementation of proteins to embryos may impact future muscle structure. We hypothesized that proteins from chicken embryo muscle extract (CEME) caused by the unique, natural composition and biocompatibility can supply additional proteins. However, supplemented proteins are actively metabolized, which may reduce their utilization for improved muscle synthesis. Nevertheless, CEME can be transported and protected by graphene oxide (GO). The objective of the present work was to investigate the effects of in ovo-injected CEME and the complex of GO-CEME on embryonic cell cultures and the growth of chicken embryo hind limb muscle. Toxicity and cell proliferation were measured in vitro with cell cultures and mortality, morphology, histology, and blood biochemistry in vivo with embryos. CEME increased the number of cells and nuclei in muscle, but the complex GO-CEME did not further improve the muscle structure. The results indicate a vital role of CEME as in ovo enhancer of muscle development in broilers.

Abstract

The effects of CEME and it complex with GO injected in ovo on the growth and development of chicken embryo hindlimb muscle were investigated. First, the preliminary in vitro study on primary muscle precursor cell culture obtained from a nine-day-old chicken embryo was performed to assess toxicity (MTT assay) of CEME, GO (100 ppm) and it complex with different concentrations (1, 2, 5, and 10 wt.%). The effect on cell proliferation was investigated by BrdU assay. CEME at concentrations 1–5% increased cell proliferation, but not the complex with GO. In vitro cytotoxicity was highest in 10% and GO groups. Next, the main experiment with chicken embryos was performed with CEME, GO and it complex injected in ovo on day one of embryogenesis. On day 20 of embryogenesis survival, morphological development, histological structure of the muscle, and biochemical parameters of blood serum of the embryos were measured. No negative effect on mortality, body weight, or biochemistry of blood after use of CEME or GO-CEME complexes was observed. Interestingly, the slight toxicity of GO, observed in in vitro studies, was not observed in vivo. The use of CEME at the levels of 2% and 5% improved the structure of the lower limb muscle by increasing the number of cells, and the administration of 2% CEME increased the number of nuclei visible in the stained cross-section of the muscle. The complex GO-CEME did not further improve the muscle structure. The results indicate that CEME can be applied as an in ovo enhancer of muscle development in broilers.

Pristine graphene and graphene oxide induce multi-organ defects in zebrafish (Danio rerio) larvae/juvenile: an in vivo study

Graphene-based nanomaterials (GBNs) have been widely used in various fields nowadays. However, they are reported to be highly toxic to some aquatic organisms. However, the multi-organ toxicity caused by pristine graphene (pG) and graphene oxide (GO) to the developing zebrafish (Danio rerio) larvae or juvenile and the underlying mechanisms is not fully known. Therefore, in the present study, the effect of pG and GO with environmental concentrations (0, 5, 10, 15, 20, and 25 μg/L of pG; 0, 0.1, 0.2, 0.3, and 0.4 mg/mL of GO) on multi-organ system in developing zebrafish larvae was experimentally assessed. The pG and GO were found to accumulate in the brain tissue that also caused significant changes in the heart beat and survival rate. The sizes of hepatocytes were reduced. Altered axonal integrity, affecting axon length and pattern in "Tg(mbp:eGFP) transgenic lines" was also observed. In addition, the results indicated pathological effects in major organs and with disrupted mitochondrial structure was quite obvious. The pG and GO bioaccumulation leads to multi organ toxicity in zebrafish larvae. In future, the existence of the current study can be extrapolated to other aquatic system in general and in particularly to humans.

Graphene oxide nanofilm and chicken embryo extract decrease the invasiveness of HepG2 liver cancer cells

Background

The extracellular matrix (ECM) is a mosaic of various structural and functional proteins that cooperate with the cell, regulate adhesion, and consequently manage its further fate. Liver destruction is accompanied by a disruption of the physicochemical properties of the ECM which deregulates the cell–ECM interaction and can lead to uncontrolled proliferation and neoplastic transformation of cells. Therefore, it can be assumed that ECM modification and restoration of its characteristics for healthy tissue may counteract uncontrolled cell proliferation. The purpose of the presented research model was to optimise the physical characteristics of ECM by introducing a graphene oxide plane/nanofilm (nfGO) and enriching the cell environment with potentially missing proteins by adding a functional protein cocktail (chicken embryo liver extract) and determine the impact of these factors on cell–ECM cooperation and its consequences on adhesion, proliferation, and cell phase, which are factors of the invasiveness of cancer cells.

Results

Experiments were performed with non-cancer HS-5 cells and liver cancer cells HepG2 and C3A. The cells were divided into four groups: (1) control, (2) cultured on nfGO, (3) cultured with the addition of chicken embryo liver extract (CELE) and (4) cultured on the nfGO with the addition of CELE. CELE contained 1735 proteins; the top 57 of these proteins have been presented. The use of nfGO as well as CELE and nfGO + CELE reduced the proliferation of HepG2 cancer cells to the greatest extent; this is in contrast to non-cancer cells and also to C3A cancer cells. Furthermore, the combined use of the CELE protein cocktail and GO substrate effectively resulted in a decrease in the population of HepG2 cells in the G0/G1 phase and an increase of the population in G2/M. Molecular analysis of HepG2 cancer cells also showed an increase in the expression of genes responsible for adhesion such as focal adhesion kinase (fak), e-cadherin, and n-cadherin and a decrease in β-catenin, which is considered a proto-oncogene.

Conclusions

Studies have shown that both the GO surface structure on which the cells are grown as well as the presence of a multi-component natural cocktail of regulatory proteins, can modify the expression of integrins, increase adhesion and, as a consequence, proliferation and the cell cycle—entering the resting phase. For the first time, it has been documented that hepatic cancer cells of the HepG2 line under the influence of stimuli derived from mimic ECM (graphene oxide) in interaction with a unique protein complex derived from chicken liver embryo decreased of the invasiveness of cancer cells.

Developmental toxicity of carbon nanoparticles during embryogenesis in chicken

Nanoparticles (NPs) are very small particles present in a wide range of materials. There is a dearth of knowledge regarding their potential secondary effects on the health of living organisms and the environment. Increasing research attention, however, has been directed toward determining the effects on humans exposed to NPs in the environment. Although the majority of studies focus on adult animals or populations, embryos of various species are considered more susceptible to environmental effects and pollutants. Hence, research studies dealing mainly with the impacts of NPs on embryogenesis have emerged recently, as this has become a major concern. Chicken embryos occupy a special place among animal models used in toxicity and developmental investigations and have also contributed significantly to the fields of genetics, virology, immunology, cell biology, and cancer. Their rapid development and easy accessibility for experimental observance and manipulation are just a few of the advantages that have made them the vertebrate model of choice for more than two millennia. The early stages of chicken embryogenesis, which are characterized by rapid embryonic growth, provide a sensitive model for studying the possible toxic effects on organ development, body weight, and oxidative stress. The objective of this review was to evaluate the toxicity of various types of carbon black nanomaterials administered at the beginning of embryogenesis in a chicken embryo model. In addition, the effects of diamond and graphene NPs and carbon nanotubes are reviewed.

High resolution, label-free photoacoustic imaging of live chicken embryo developing in bioengineered eggshell

Chicken embryos have been proven to be an attractive vertebrate model for biomedical research. They have helped in making significant contributions for advancements in various fields like developmental biology, cancer research and cardiovascular studies. However, a non-invasive, label-free method of imaging live chicken embryo at high resolution still needs to be developed and optimized. In this work, we have shown the potential of photoacoustic tomography (PAT) for imaging live chicken embryos cultured in bioengineered eggshells. Laser pulses at wavelengths of 532 and 740 nm were used for attaining cross-sectional images of chicken embryos at different developmental stages. Cross-sections along different depths were imaged to gain knowledge of the relative depth of different vessels and organs. Due to high optical absorption of vasculature and embryonic eye, images with good optical contrast could be acquired using this method. We have thus reported a label-free method of performing cross-sectional imaging of chicken embryos at high resolution demonstrating the capacity of PAT as a promising tool for avian embryo imaging.

On the epigenetic role of guanosine oxidation

Chemical modifications of DNA and RNA regulate genome functions or trigger mutagenesis resulting in aging or cancer. Oxidations of macromolecules, including DNA, are common reactions in biological systems and often part of regulatory circuits rather than accidental events. DNA alterations are particularly relevant since the unique role of nuclear and mitochondrial genome is coding enduring and inheritable information. Therefore, an alteration in DNA may represent a relevant problem given its transmission to daughter cells. At the same time, the regulation of gene expression allows cells to continuously adapt to the environmental changes that occur throughout the life of the organism to ultimately maintain cellular homeostasis. Here we review the multiple ways that lead to DNA oxidation and the regulation of mechanisms activated by cells to repair this damage. Moreover, we present the recent evidence suggesting that DNA damage caused by physiological metabolism acts as epigenetic signal for regulation of gene expression. In particular, the predisposition of guanine to oxidation might reflect an adaptation to improve the genome plasticity to redox changes.

Graphene oxide induces cardiovascular defects in developing zebrafish (Danio rerio) embryo model: In-vivo toxicity assessment

Graphene oxide (GO) has wide engineering applications in various areas, including electronics, energy storage, pharmaceuticals, nanomedicine, environmental remediation and biotechnology, because of its unique physico-chemical properties. In the present study, the risk-related information of GO was evaluated to examine the potential ecological and health risks of developmental toxicity. Although the overall developmental toxicity of GO has been well characterized in zebrafish, however, its release effect at a certain concentration of living organisms with specific cardiovascular defects remains largely elusive. Therefore, this study was conducted to further evaluate the toxicity of GO on embryonic development and cardiovascular defects in zebrafish embryos used as an in-vivo animal model. As a result, the presence of GO at a small concentration (0.1-0.3 mg/mL) does not affect the embryonic development. However, GO at higher concentrations (0.4-1 mg/mL) induces significant embryonic mortality, increase heartbeat, delayed hatching, cardiotoxicity, cardiovascular defects, retardation of cardiac looping, increased apoptosis and decreased hemoglobinization. These results provide valuable information that can be used to study the eco-toxicological effects of GO for assessing its bio-safety according to environmental concentration. In addition, the present results would also be usefully utilized for understanding the environmental risks associated with GO on human health in general.

Graphene oxide down-regulates genes of the oxidative phosphorylation complexes in a glioblastoma

BACKGROUND

Recently different forms of nanographene were proposed as the material with high anticancer potential. However, the mechanism of the suppressive activity of the graphene on cancer development remains unclear. We examined the effect of oxygenated, reduced and pristine graphene on the gene expression in glioblastoma U87 cell line.

RESULTS

Conducting microarrays and RT-qPCR analysis we explored that graphene oxide (rather than reduced graphene oxide and pristine graphene) down-regulates the mRNA expression of mitochondrial oxidative phosphorylation (OXPHOS) nuclear genes of complexes I, III, IV and V. The presented results provide first evidence for the hypothesis that the suppressed growth of GBM can be the consequence of down-regulation of OXPHOS protein expression and decreased ATP level.

CONCLUSIONS

We suggest that changes in the expression of OXPHOS genes identified in our study may mediate the anti-proliferative and anti-migratory effects of graphene oxide in glioblastoma cells. However, further investigations with different cell lines, regarding expression, regulation and activity of OXPHOS genes identified in our study is necessary to elucidate the mechanism mediating the anti-proliferative and anti-migratory effects of graphene oxide in glioblastoma cells.

Graphene-Based Nanomaterials Toxicity in Fish

Due to their unique physicochemical properties, graphene-based nanoparticles (GPNs) constitute one of the most promising types of nanomaterials used in biomedical research. GPNs have been used as polymeric conduits for nerve regeneration and carriers for targeted drug delivery and in the treatment of cancer via photothermal therapy. Moreover, they have been used as tracers to study the distribution of bioactive compounds used in healthcare. Due to their extensive use, GPN released into the environment would probably pose a threat to living organisms and ultimately to human health. Their accumulation in the aquatic environment creates problems to aquatic habitats as well as to food chains. Until now the potential toxic effects of GPN are not properly understood. Despite agglomeration and long persistence in the environment, GPNs are able to cross the cellular barriers successfully, entered into the cells, and are able to interact with almost all the cellular sites including the plasma membrane, cytoplasmic organelles, and nucleus. Their interaction with DNA creates more potential threats to both the genome and epigenome. In this brief review, we focused on fish, mainly zebrafish (Danio rerio), as a potential target animal of GPN toxicity in the aquatic ecosystem.

Pristine graphene induces cardiovascular defects in zebrafish (Danio rerio) embryogenesis

The multiple effect of pristine graphene (pG) toxicity on cardiovascular developmental defects was assessed using zebrafish as a model. Recently, the nanotoxicity is emerging as a critical issue, and it is more significant in embryogenesis. Especially, graphene and its derivatives have attracted a lot of interest in biomedical applications. However, very little is known about the toxic effects of pG which has been widely used carbon nanomaterial according to concentration and its effects on biological and cardiovascular development. In the present study, we examined the development of zebrafish embryos by exposing to pG (5, 10, 15, 20 and 25 μg/L) under different developmental toxicity end-points such as cardiotoxicity, cardiovascular defect, retardation of cardiac looping, apoptosis and globin expression analysis. For this, the developmental cardiotoxicity of pG at different concentrations and the specific cardiovascular defects thereof were elucidated for the first time. As a result, the exposure to pG was found to be a potential risk factor to cardiovascular system of zebrafish embryos. However, a further study on the variations of physical, molecular properties and mechanisms of nanotoxicity which vary depending on production method and surface functionalization is required. In addition, the potential risks of pG flakes to aquatic organisms and human health should be considered or checked before releasing them to the environment.

Effect of copper nanoparticles on the mineral content of tissues and droppings, and growth of chickens

We hypothesised that copper nanoparticles (NanoCu), because of their high physicochemical reactivity and bioavailability, could be used in much smaller quantities than bulk Cu, consequently reducing excretion of Cu into the environment. The objective of the study was to evaluate the effects of various levels of NanoCu on the development and growth of broiler chickens, in order to establish an optimum level of NanoCu dietary supplementation. Broiler chickens were randomly divided into five groups of 10 birds each. The control group received 7.5 mg Cu/kg feed (standard level) as CuSO₄, while groups fed with complexes of NanoCu and starch received 25%, 50%, 75% and 100% of the standard level of Cu used in the control group. Chicken growth and excretion of Cu, Fe and Zn were measured during the growth period from d 7 to 42. At d 42, the slaughter characteristics, the content of Cu, Fe and Zn in the breast muscle and liver, and the oxidative status were analysed. The results indicate that using NanoCu can reduce the standard level of Cu from CuSO₄ supplementation by 75% without jeopardising animal growth, and at the same time significantly decreasing Cu excretion into the environment.

TiO2 nanoparticles induce omphalocele in chicken embryo by disrupting Wnt signaling pathway

Titanium dioxide nanoparticles (TiO₂ NPs) are among abundantly used metal oxide NPs but their interactions with biomolecules and subsequent embryonic toxicity in higher vertebrates is not extensively reported. Physicochemical interactions of TiO₂ NPs with egg albumen reveals that lower doses of TiO₂ NPs (10 and 25 µg/ml) accounted for higher friccohesity and activation energy but an increment in molecular radii was recorded at higher doses (50 and 100 µg/ml). FTIR analysis revealed conformational changes in secondary structure of egg albumen as a result of electrostratic interactions between egg albumen and TiO₂ NPs. The morphometric data of chicken embryo recorded a reduction at all the doses of TiO₂ NPs, but toxicity and developmental deformity (omphalocele and flexed limbs) were recorded at lower doses only. Inductively coupled plasma optical emission spectrometry (ICP-OES) confirmed presence of Ti in chicken embryos. mRNA levels of genes involved in canonical and non-canonical Wnt signaling were lowered following TiO₂ NPs treatment resulting in free radical mediated disruption of lateral plate mesoderm and somite myogenesis. Conformational changes in egg albumen and subsequent developmental deformity in chicken embryo following TiO₂ NPs treatment warrants detailed studies of NP toxicity at lower doses prior to their biomedical applications.

Toxicity studies of six types of carbon nanoparticles in a chicken-embryo model

In the present study, the toxicity of six different types of carbon nanoparticles (CNPs) was investigated using a chicken-embryo model. Fertilized chicken eggs were divided into the following treatment groups: placebo, diamond NPs, graphite NPs, pristine graphene, small graphene oxide, large graphene oxide, and reduced graphene oxide. Experimental solutions at a concentration of 500 μg/mL were administrated into the egg albumin. Gross pathology and the rate of survival were examined after 5, 10, 15, and 20 days of incubation. After 20 days of incubation, blood samples were collected and the weight of the body and organs measured. The relative ratio of embryo survival decreased after treatment all treatments except diamond NPs. There was no correlation between the rate of survival and the ζ-potential or the surface charge of the CNPs in solution. Body and organ weight, red blood-cell morphology, blood serum biochemical parameters, and oxidative damage in the liver did not differ among the groups. These results indicate that CNPs can remain in blood circulation without any major side effects, suggesting their potential applicability as vehicles for drug delivery or active compounds per se. However, there is a need for further investigation of their properties, which vary depending on production methods and surface functionalization.