Cellular and Molecular Toxicity of Iron Oxide Nanoparticles. In: Saquib Q, Faisal M, Al-khedhairy AA, Alatar AA, editors. Cellular and Molecular Toxicology of Nanoparticles. Cham: Springer International Publishing; 2018. pp. 199-213. [DOI: 10.1007/978-3-319-72041-8_12]

Evaluating the safety and efficiency of nanomaterials: A focus on mitochondrial health

Nanomaterials (NMs) have extensive application potential in drug delivery, tissue engineering, and various other domains, attributable to their exceptional physical and chemical properties. Nevertheless, an increasing body of literature underscores the diverse safety risks are associated with NMs upon interaction with the human body, including oxidative stress and programmed cell death. Mitochondria, serving as cellular energy factories, play a pivotal role in energy metabolism and the regulation of cell fate. Organs with substantial energy demands, including the heart and brain, are highly sensitive to mitochondrial integrity, with mitochondrial impairment potentially resulting in significant dysfunction and pathologies such as as heart failure and neurodegenerative disease. This review elucidates the pathways by which NMs translocate into mitochondria, their intracellular dynamics, and their impact on mitochondrial morphology, respiratory chain activity, and metabolic processes. We further investigate associated molecular mechanisms, including mitochondrial dynamic imbalance, calcium overload, and oxidative stress, and elucidate the pivotal roles of mitochondria in different forms of programmed cell death such as apoptosis and autophagy. Finally, we offer recommendations regarding the safety and efficacy of NMs for medical applications. By systematically analyzing the interactions and molecular mechanisms between NMs and mitochondria, this paper aims to enhance the toxicological evaluation framework of NMs and provide a foundational reference and theoretical basis for their clinical utilization.

Cytotoxic and radical activities of metal-organic framework modified with iron oxide: Biological and physico-chemical analyses

Metal-organic framework (MOF) modified with iron oxide, Fe3O4-MOF, is a perspective drug delivery agent, enabling magnetic control and production of active hydroxyl radicals, •OH, via the Fenton reaction. This paper studies cytotoxic and radical activities of Fe-containing nanoparticles (NPs): Fe3O4-MOF and its components - bare Fe3O4 and MOF (MIL-88B). Luminous marine bacteria Photobacteriumphosphoreum were used as a model cellular system to monitor bioeffects of the NPs. Neither the NPs of Fe3O4-MOF nor MOF showed cytotoxic effects in a wide range of concentrations (<10 mg/L); while Fe3O4 was toxic at >3·10-3 mg/L. The NPs of Fe3O4 did not affect the bacterial bioluminescence enzymatic system; their toxic effect was attributed to cellular membrane processes. The integral content of reactive oxygen species (ROS) was determined using a chemiluminescence luminol assay. Bacteria mitigated excess of ROS in water suspensions of Fe3O4-MOF and MOF, maintaining bioluminescence intensity closer to the control; this resulted in low toxicity of these NPs. We estimated the activity of •OH radicals in the NPs samples with physical and chemical methods - spin capture technology (using electron paramagnetic resonance spectroscopy) and methylene blue degradation. Physico-chemical interpretation of cellular responses is provided in terms of iron content, iron ions release and •OH radical production.

Molecular MR Imaging of Prostate Cancer by Specified Iron Oxide Nanoparticles With PSMA-11 Peptides: A Preclinical Study

BACKGROUND

Prostate-specific membrane antigen (PSMA) can provide a prostate cancer (PCa) detection approach in positron emission tomography (PET) using Food and Drug Administration (FDA)-approved PSMA-11 peptide. There are some studies evaluated magnetic-nanoprobes for PSMA detection by MRI, using non-FDA-approved ligands including antibodies or peptides, which are not as specific as PSMA-11.

PURPOSE

To assess targeted iron oxide nanoparticles (IONPs) by PSMA-11 peptides as a potential specific nano-molecular probes to investigate a PSMA+ PCa-xenograft model by MRI.

STUDY TYPE

Prospective.

ANIMAL MODEL

Twenty male C57BL6 nude mice induced subcutaneously PSMA+ LNCaP cell line tumor.

FIELD STRENGTH/SEQUENCE

1.5 T, T2-W Fast Spin echo and T2*-W Gradient echo.

ASSESSMENT

Coated IONPs with Carboxymethylated-dextran (DNPs) and with bovine serum albumin (BNPs), as well as, targeted DNPs with PSMA-11-HYNIC peptide (TDNPs) and targeted BNPs with PSMA-11-HBED peptide (TBNPs) were injected intravenously with dose 2.8 mg Fe/kg. Coronal T2-W and the T2*-W images were obtained before and 4 hours and 6 hours post-injection. Signal intensity (SI) and relative signal enhancement (RSE) were computed in two- and three-dimensional analyses. Histological analysis of tumors was evaluated, and the Fe distribution within the body based on atomic absorption spectroscopy was calculated.

STATISTICAL TESTS

One-way ANOVA followed by Tukey's multiple comparison test, Paired-samples T-test, P < 0.05 was considered significant.

RESULTS

A reduction in T2-W SI was achieved as 22 ± 7%, 59 ± 3%, 65 ± 5%, and 78 ± 3% respectively for BNPs, TBNPs, DNPs, and TDNPs 6 hours post-injection. The most difference between targeted and non-targeted groups was observed at 6 hours for PSMA-11-HBED, and at 4 hours for PSMA-11-HYNIC. RSE indicated 88.6 ± 3.1% and 80.7 ± 3.2% enhanced contrast between tumor and muscle region for TBNPs and TDNPs on T2*-W images.

CONCLUSIONS

Both TBNPs and TDNPs are promising novel nano-molecular probes for PSMA+ PCa tumor detection. The injection dose of non-targeted IONPs can be reduced by using targeted nanoprobes three times for BNPs and two times for DNPs.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 1.

Interaction between iron oxide nanoparticles (IONs) and primary human immune cells: An up-to-date review of the literature

Nanotechnology has been gaining more and more momentum lately and the potential use of nanomaterials such as nanoparticles (NPs) continues to grow in a variety of activity sectors. Among the NPs, iron oxide nanoparticles (IONs) have retained an increasing interest from the scientific community and industrials due to their superparamagnetic properties allowing their use in many fields, including medicine. However, some undesired effects of IONs and potential risk for human health are becoming increasingly reported in several studies. Although many in vivo studies reported that IONs induce immunotoxicity in different animal models, it is not clear how IONs can alter the biology of primary human immune cells. In this article, we will review the works that have been done regarding the interaction between IONs and primary immune cells. This review also outlines the importance of using primary immune cells in risk assessment of NPs as a reliable strategy for encouraging non-animal studies approaches, to determine risks that might affect the human immune system following different exposure scenarios. Taken all together, the reported observations help to get a more global picture on how IONs alter the human immune system especially the fact that inflammation, known to involve several immune cell types, is frequently reported as an undesired effect of IONs.

The dependences of mesenchymal stem cells commitments on the size, concentration, internalization and exposure time of Iron Oxide Nanoparticles through F-actin, Lamin A and ROS

Though magnetic iron oxide nanoparticles (IONPs) are approved for clinical use as contrast agents for MR imaging in United States and Europe, and are widely used to label cells in research, the relationship between IONPs and mesenchymal stem cells (MSCs) is not fully addressed. Here the effects of consistently appeared γ-Fe₂ O₃ on the lineage commitment of MSCs were studied to optimize applications of IONPs in MSCs upon verification of viability. 30 nm 10 μg/mL induced highest promotions on osteogenesis, while 30 and 50 nm of 100 μg/mL elicited most chondrogensis in 14 days, where the effects on ALP, GAG and SOX9 appeared after 7 days, while on RUNX2 came out after 10 days. γ-Fe₂ O₃ enhanced intracellular and extracellular Fe³⁺ and ROS, modulated F-actin and decreased Lamin A of MSCs at different time scale. The disturbances of F-actin, Lamin A or ROS altered the effects of γ-Fe₂ O₃ on MSC differentiation. Our results demonstrate that different size, concentration and modulation of γ-Fe₂ O₃ are needed in its MSC applications for bone and cartilage tissues. Furthermore, an undocumented phenomenon that the modulation of F-actin affected the Lamin A expression in MSCs was observed.

Iron oxide nanoparticles cause surface coating- and core chemistry-dependent endothelial cell ferroptosis

Iron oxide nanoparticles (IONPs) are mostly intended to be administrated intravenously, understanding the interaction of IONPs with vascular endothelial cells is extremely crucial for developing safe application regimes of IONPs. In this work, interactions of three kinds of IONPs to endothelial cells were investigated both in human umbilical vein endothelial cells (HUVECs) and in healthy mice. Both meso-2,3-dimercaptosuccinic acid (DMSA) coated Fe₃O₄ NPs (DMSA-Fe₃O₄ NPs) and DMSA-Fe₂O₃ NPs induced cell growth inhibition, while polyglucose sorbitol carboxymethyether coated Fe₂O₃ NPs(PSC-Fe₂O₃ NPs) did not. The PSC coating inhibited the cellular uptake of the IONPs. Both DMSA-Fe₃O₄ and DMSA-Fe₂O₃ NPs induced ferroptosis of HUVEC through upregulating phospholipid peroxides, which could be inhibited by typical ferroptosis inhibitors ferrostatin-1, Trolox and deferoxamine. Moreover, transforming growth factor beta 1 (TGFβ1) was upregulated by DMSA-Fe₃O₄ NPs at protein and gene level. The inhibitor of TGFβ1 receptor LY210 could reduce the effect. When being intravenously injected in mice, DMSA-Fe₃O₄ NPs were observed locating in the liver, increased the levels of lipid peroxidation (4-hydroxynonenal), acyl-CoA synthetase long-chain family member 4(ACSL4) and TGFβ1, indicating ferroptosis occurrence in vivo. The ferroptosis of vascular endothelial cells in exposure with IONPs depended on the surface coating and core chemistry of the NPs. Both DMSA-Fe₃O₄ NPs and DMSA-Fe₂O₃ NPs could induce the ferroptosis of endothelial cells, while PSC-Fe₂O₃ NPs did not induce ferroptosis and apoptosis possibly due to the very low cellular uptake. DMSA-Fe₃O₄ NPs and TGFβ1 formed feedforward loop to induce ferroptosis.

Magnetic particle imaging: tracer development and the biomedical applications of a radiation-free, sensitive, and quantitative imaging modality

Magnetic particle imaging (MPI) is an emerging tracer-based modality that enables real-time three-dimensional imaging of the non-linear magnetisation produced by superparamagnetic iron oxide nanoparticles (SPIONs), in the presence of an external oscillating magnetic field. As a technique, it produces highly sensitive radiation-free tomographic images with absolute quantitation. Coupled with a high contrast, as well as zero signal attenuation at-depth, there are essentially no limitations to where that can be imaged within the body. These characteristics enable various biomedical applications of clinical interest. In the opening sections of this review, the principles of image generation are introduced, along with a detailed comparison of the fundamental properties of this technique with other common imaging modalities. The main feature is a presentation on the up-to-date literature for the development of SPIONs tailored for improved imaging performance, and developments in the current and promising biomedical applications of this emerging technique, with a specific focus on theranostics, cell tracking and perfusion imaging. Finally, we will discuss recent progress in the clinical translation of MPI. As signal detection in MPI is almost entirely dependent on the properties of the SPION employed, this work emphasises the importance of tailoring the synthetic process to produce SPIONs demonstrating specific properties and how this impacts imaging in particular applications and MPI's overall performance.

Fe3O4 nanoparticles coated with carboxymethyl chitosan containing curcumin in combination with hyperthermia induced apoptosis in breast cancer cells

Many studies have demonstrated that curcumin has potential anticancer properties. This research aims to study the effect of iron (II, III) oxide (Fe3O4) nanoparticles coated with carboxymethyl chitosan containing curcumin combination with hyperthermia on breast cancer cells. Magnetic nanoparticles coated with carboxymethyl chitosan containing curcumin (MNP-CMC-CUR) were prepared and specified. MCF-7, MDA-MB-231, and human fibroblast cells were treated with free curcumin and MNP-CMC-CUR at concentrations of 0-60 µM and at different time points. A combined therapy of MNP-CMC-CUR and hyperthermia was performed on MCF-7 cells. The cytotoxicity of curcumin and MNP-CMC-CUR combined with hyperthermia was assessed by MTT. The changes in TP53 and CASPASE3 gene expression were evaluated using real-time PCR. Both cell apoptosis and cell cycle were studied by Annexin/PI staining. The results of MTT showed that the IC50 amount of MNP-CMC-CUR has significantly decreased compared to free curcumin (p < 0.05) and MNP-CMC-CUR in combination with the hyperthermia, and significantly reducing the metabolic activity of the cells (p < 0.05). Real-time PCR results revealed the up-regulation of TP53 and CASPASE3 (p < 0.05). The combinational therapy-induced cell apoptosis (64.51%) and sub-G1 cell cycle were arrested in MCF-7 cells. Based on these observations, a combination of MNP-CMC-CUR with hyperthermia could inhibit the proliferation of MCF-7 cells.

Blue light-triggered Fe2+-release from monodispersed ferrihydrite nanoparticles for cancer iron therapy

Site-specific Fe²⁺ generation is promising for tumor therapy. Up to now, reported materials or systems for Fe²⁺ delivery do not naturally exist in the body, and their biological safety and toxicity are concerned. Herein, inspired by the natural biomineral ferrihydrite in ferritin, we synthesized monodispersed ferrihydrite nanoparticles and demonstrated a light triggered Fe²⁺ generation on tumor sites. Ferrihydrite nanoparticles of 20-30 nm in diameter possessed high cellular uptake efficiency and good biocompatibility. Under common blue light illumination, a large amount of Fe²⁺ could be released from ferrihydrite and promote the iron/reactive oxygen species (ROS)-related irreversible DNA fragmentation and glutathione peroxidase 4 (GPX4) inhibition, which led to the apoptosis- and ferroptosis-depended cancer cell proliferation inhibition. On mice, this method induced tumor associated macrophage (TAM) polarization from the tumor-promoting M2 type to the tumor-killing M1 type. With the intravenous pre-injection of ferrihydrite, the combinational effects of the light/Fe²⁺-approach attenuated pulmonary metastasis on mice. These results demonstrated a novel external light controlled Fe²⁺-generation approach based on biomineral, which will fully tap the anti-cancer potential of Fe²⁺ in chemo-dynamic, photo-dynamic and immune-activating therapies.

Risk assessment of iron oxide nanoparticles in an aquatic ecosystem: A case study on Biomphalaria glabrata

Iron oxide nanoparticles (IONPs) have been applied in several sectors in the environmental field, such as aquatic nanoremediation, due to their unique superparamagnetic and nanospecific properties. However, the knowledge of chronic toxicity of IONPs on aquatic invertebrate remains limited. Thus, the present study aimed to analyze the chronic toxicity of gluconic acid-functionalized IONPs (GLA-IONPs) and their dissolved counterpart (FeCl₃) to freshwater snail Biomphalaria glabrata. GLA-IONPs were synthesized and characterized by multiple techniques, and the snails were exposed to both Fe forms at environmentally relevant concentrations (1.0-15.6 mg L^-1) for 28 days. The bioaccumulation, mortality rate, behavior impairments, morphological alterations, fecundity and fertility of snails were analyzed. Results showed that GLA-IONPs induced high iron bioaccumulation in the entire soft tissue portion. Chronic exposure to GLA-IONP increased the behavioral impairments of snails compared to iron ions and control groups. Both Fe forms reduced the fecundity, while the mortality and reduced fertility were observed only after the exposure to GLA-IONPs at 15.6 mg L^-1. Overall results indicated the behavioral impairments and reproductive toxicity associated, possibly, to bioaccumulation of GLA-IONPs in the B. glabrata. These results can be useful for the development of eco-friendly nanotechnologies.

Toxicity assessment of superparamagnetic iron oxide nanoparticles in different tissues

Superparamagnetic iron oxide nanoparticles (SPIONs) have been employed in several biomedical applications where they facilitate both diagnostic and therapeutic aims. Although the potential benefits of SPIONs with different surface chemistry and conjugated targeting ligands/proteins are considerable, complicated interactions between these nanoparticles (NPs) and cells leading to toxic impacts could limit their clinical applications. Hence, elevation of our knowledge regarding the SPION-related toxicity is necessary. Here, the present review article will consider current studies and compare the potential toxic effect of SPIONs with or without identical surface chemistries on different cell lines. It centers on cellular and molecular mechanisms underlying toxicity of SPIONs. Likewise, emphasis is being dedicated for toxicity of SPIONs in various cell lines, in vitro and animal models, in vivo.

Organ-specific toxicity of magnetic iron oxide-based nanoparticles

The unique properties of magnetic iron oxide nanoparticles determined their widespread use in medical applications, the food industry, textile industry, which in turn led to environmental pollution. These factors determine the long-term nature of the effect of iron oxide nanoparticles on the body. However, studies in the field of chronic nanotoxicology of magnetic iron particles are insufficient and scattered. Studies show that toxicity may be increased depending on oral and inhalation routes of administration rather than injection. The sensory nerve pathway can produce a number of specific effects not seen with other routes of administration. Organ systems showing potential toxic effects when injected with iron oxide nanoparticles include the nervous system, heart and lungs, the thyroid gland, and organs of the mononuclear phagocytic system (MPS). A special place is occupied by the reproductive system and the effect of nanoparticles on the health of the first and second generations of individuals exposed to the toxic effects of iron oxide nanoparticles. This knowledge should be taken into account for subsequent studies of the toxicity of iron oxide nanoparticles. Particular attention should be paid to tests conducted on animals with pathologies representing human chronic socially significant diseases. This part of preclinical studies is almost in its infancy but of great importance for further medical translation on nanomaterials to practice.

Characteristics of iron status, oxidation response, and DNA methylation profile in response to occupational iron oxide nanoparticles exposure

Although the growing development and application of iron oxide nanoparticles (IONPs) may pose exposure risk and adverse health outcomes, biological changes due to occupational exposure remain unexplored. This cross-sectional study recruited 23 workers at a plant that manufactures IONPs and 23 age- and sex-matched controls without metal-rich occupational hazards exposure. Exposure metrics at worksites were monitored, and iron status, oxidation markers, and methylation profiles of genomic DNA in peripheral blood were measured using corresponding enzyme-linked immunosorbent assays and methylation-specific polymerase chain reaction (PCR), respectively. The mass concentration, number counting, and surface area concentration of airborne particles at the worksite significantly increased during the work process of manufacturing/handling IONPs. Overall, compared to controls, workers exhibited increased 5-hydroxymethylcytosine (5hmC) levels without changes in 5-methylcytosine (5mC), hepcidin methylation, iron, soluble transferrin receptor (sTfR), ferritin, hepcidin, 8-hydroxydeoxyguanosine, and glutathione. A positive correlation was found between 5hmC and IONP exposure year with adjustment for age, sex, and cotinine using partial correlation analyses ( r = 0.521, p < 0.001). After stratification of INOPs exposure and 5hmC levels, the univariate general linear model with adjustment for age, sex, and cotinine found that the estimated mean levels of 5mC and sTfR in subjects with low and high 5hmC levels among controls were 11% and 14.4% ( p ≤ 0.01) and 80.9 nM and 70.3 nM ( p < 0.05), respectively. The estimated mean levels of sTfR in workers and controls with low 5hmC levels were 88.3 nM and 68.7 nM ( p ≤ 0.01). Multivariate linear regression analyses suggested an association between sTfR and 5hmC (standardized β = −0.420, p = 0.014) and female sex (standardized β = 0.672, p < 0.001) for subjects with low 5hmC levels. These findings suggest that increased 5hmC could be differentially employed to monitor an epigenetic signature with steady iron homeostasis for occupational IONP-exposed individuals who are likely to experience early but specific decreased sTfR, especially for females concurrent with the onset of increment in 5hmC at low level.

Magnetite nanoparticles effects on adverse responses of aquatic and terrestrial animal models

Among pollutants, nanoparticles (NPs) consist a potential environmental hazard, as they could possibly harm the aquatic and terrestrial ecosystems while having unpredictable repercussions on human health. Since monitoring the impact of NPs on aquatic and terrestrial life is challenging, due to the differential sensitivities of organisms to a given nanomaterial, the present study examines magnetite nanoparticles' mediated toxicity in different animal models, representing distinctive environments (terrestrial and aquatic). Oxidative, proteolytic and genotoxic effects were evaluated on the hemocytes of the snail Cornu aspersum; in addition to those, apoptotic effects were measured in gills and liver of the zebrafish Danio rerio, and the prussian carp Carassius gibelio. All biochemical parameters studied increased significantly in animals after 8 days exposure to NPs. Inter-species and inter-tissues differences in responses were evident. Our results suggest a common toxicity response mechanism functioning in the tissues of the three animals studied that is triggered by magnetite NPs. The simultaneous use of these parameters could be established after further investigation as a reliable multi-parameter approach for biomonitoring of terrestrial and aquatic ecosystems against magnetite nanoparticles. Additionally, the results of our study could contribute to the design of studies for the production and rational utilization of nanoparticles.

Application of Gray Level co-Occurrence Matrix Algorithm for Detection of Discrete Structural Changes in Cell Nuclei After Exposure to Iron Oxide Nanoparticles and 6-Hydroxydopamine

The gray level co-occurrence matrix (GLCM) algorithm is a contemporary computational biology method which, today, is frequently used to detect small changes in texture that are not visible using conventional techniques. We demonstrate that the toxic compound 6-hydroxydopamine (6-OHDA) and iron oxide nanoparticles (IONPS) have opposite effects on GLCM features of cell nuclei. Saccharomyces cerevisiae yeast cells were treated with 6-OHDA and IONPs, and imaging with GLCM analysis was performed at three different time points: 30 min, 60 min, and 120 min after the treatment. A total of 200 cell nuclei were analyzed, and for each nucleus, 5 GLCM parameters were calculated: Angular second moment (ASM), Inverse difference moment (IDM), Contrast (CON), Correlation (COR) and Sum Variance (SVAR). Exposure to IONPs was associated with the increase of ASM and IDM while the values of SVAR and COR were reduced. Treatment with 6-OHDA was associated with the increase of SVAR and CON, while the values of nuclear ASM and IDM were reduced. This is the first study to indicate that IONPs and 6-OHDA have opposite effects on nuclear texture. Also, to the best of our knowledge, this is the first study to apply the GLCM algorithm in Saccharomyces cerevisiae yeast cells in this experimental setting.

Quercetin conjugated with superparamagnetic iron oxide nanoparticles improves learning and memory better than free quercetin via interacting with proteins involved in LTP

Biomedical application of quercetin (QT) as an effective flavonoid has limitations due to its low bioavailability. Superparamagnetic iron oxide nanoparticle (SPION) is a novel drug delivery system that enhances the bioavailability of quercetin. The effect of short time usage of quercetin on learning and memory function and its signaling pathways in the healthy rat is not well understood. The aim of this study was to investigate the effect of free quercetin and in conjugation with SPION on learning and memory in healthy rats and to find quercetin target proteins involved in learning and memory using Morris water maze (MWM) and computational methods respectively. Results of MWM show an improvement in learning and memory of rats treated with either quercetin or QT-SPION. Better learning and memory functions using QT-SPION reveal increased bioavailability of quercetin. Comparative molecular docking studies show the better binding affinity of quercetin to RSK2, MSK1, CytC, Cdc42, Apaf1, FADD, CRK proteins. Quercetin in comparison to specific inhibitors of each protein also demonstrates a better QT binding affinity. This suggests that quercetin binds to proteins leading to prevent neural cell apoptosis and improves learning and memory. Therefore, SPIONs could increase the bioavailability of quercetin and by this way improve learning and memory.