Nanoparticle Exposure Research Articles

Titanium nanoparticles released from orthopedic implants induce muscle fibrosis via activation of SNAI2

Titanium alloys represent the prevailing material employed in orthopedic implants, which are present in millions of patients worldwide. The prolonged presence of these implants in the human body has raised concerns about possible health effects. This study presents a comprehensive analysis of titanium implants and surrounding tissue samples obtained from patients who underwent revision surgery for therapeutic reasons. The surface of the implants exhibited nano-scale corrosion defects, and nanoparticles were deposited in adjacent samples. In addition, muscle in close proximity to the implant showed clear evidence of fibrotic proliferation, with titanium content in the muscle tissue increasing the closer it was to the implant. Transcriptomics analysis revealed SNAI2 upregulation and activation of PI3K/AKT signaling. In vivo rodent and zebrafish models validated that titanium implant or nanoparticles exposure provoked collagen deposition and disorganized muscle structure. Snai2 knockdown significantly reduced implant-associated fibrosis in both rodent and zebrafish models. Cellular experiments demonstrated that titanium dioxide nanoparticles (TiO2 NPs) induced fibrotic gene expression at sub-cytotoxic doses, whereas Snai2 knockdown significantly reduced TiO2 NPs-induced fibrotic gene expression. The in vivo and in vitro experiments collectively demonstrated that Snai2 plays a pivotal role in mediating titanium-induced fibrosis. Overall, these findings indicate a significant release of titanium nanoparticles from the implants into the surrounding tissues, resulting in muscular fibrosis, partially through Snai2-dependent signaling.Graphical

ZnO nanoparticles induce melanoma-like lesions via recruiting dermal dendritic cells in barrier-damaged skin in mice

ZnO nanoparticles (NPs) are used in skin treatments and cosmetics, the toxicity of long-term and continuous exposure to ZnO NPs is unknown. Mice with epidermal barrier dysfunction revealed melanoma-like lesions after continuous exposure to ZnO NPs. However, the effects of metallic NPs on the skin microenvironment and immune system remain poorly understood. Mice with epidermal barrier failure were given continuous exposure to ZnO NPs for 7 weeks. The malignant transformation of melanocytes was induced with ZnO NPs 2.5 μg/ml for 72 h exposure. The supernatant of the culture medium from dendritic cells after being exposed to 10 μg/ml ZnO NPs for 24 h was applied to melanocytes to explore the effect of recruitment of DCs. The expressure of ZnO NPs resulted in a tendency of malignant transformation of melanocytes, the recruitment of DCs induces this process by produce inflammatory factors such as TNF-α. These DC-produced inflammatory factors, which were induced by ZnO NP exposure, increased the production of matrix metalloproteinases in melanocytes and expedited the malignant transformation process. Our findings revealed that the disrupted cutaneous microenvironment by ZnO NPs penetrated directly promoted the malignant transformation of melanocytes, which process also indirectly enhanced by the TNF-αsecreted from the recruited DCs.

Machine learning approaches to detect hepatocyte chromatin alterations from iron oxide nanoparticle exposure

This study focuses on developing machine learning models to detect subtle alterations in hepatocyte chromatin organization due to Iron (II, III) oxide nanoparticle exposure, hypothesizing that exposure will significantly alter chromatin texture. A total of 2000 hepatocyte nuclear regions of interest (ROIs) from mouse liver tissue were analyzed, and for each ROI, 5 different parameters were calculated: Long Run Emphasis, Short Run Emphasis, Run Length Nonuniformity, and 2 wavelet coefficient energies obtained after the discrete wavelet transform. These parameters served as input for supervised machine learning models, specifically random forest and gradient boosting classifiers. The models demonstrated relatively robust performance in distinguishing hepatocyte chromatin structures belonging to the group exposed to IONPs from the controls. The study's findings suggest that iron oxide nanoparticles induce substantial changes in hepatocyte chromatin distribution and underscore the potential of AI techniques in advancing hepatocyte evaluation in physiological and pathological conditions.

Toxic effects of multi-walled carbon nanotubes and ZnO nanoparticle exposure on pathology and apoptosis on the liver of Cyprinus carpio

ZnO nanoparticles (ZnONPs) and carbon nanotubes (CNTs) are frequently used nanoparticles with unique features. Aquatic organisms are exposed to a combination of contaminants in natural water systems, so the combination effect of two or more nanomaterials has caused much concern. In this study, the toxicity to the liver of common carp was explored under four weeks of exposure to single ZnONPs or in combination with multi-walled CNTs (MWCNTs). The results demonstrated that ZnONPs induced pathological changes and apoptosis in the liver. In combination, decreased pathological changes were observed in the LSC-ZnONPs group (50 mg L-1 ZnONPs and 0.25 mg L-1 MWCNTs) at the microscopic level and ultrastructural level, and increased pathological changes in the HSC-ZnONPs group (50 mg L-1 ZnONPs and 2.5 mg L-1 MWCNTs). A 52% reduction in the percentage of TUNEL-positive nuclei in the LSC-ZnONPs group and a 33% increase in the HSC-ZnONPs group were observed compared to the ZnONPs group. The mRNA expression of apoptosis-related genes, including caspase3, BAX, and XBP1, were significantly up-regulated in the exposure groups, confirming the occurrence of apoptosis. Significantly decreased caspase 3 and BAX mRNA levels in the co-exposure groups were detected compared to the ZnONPs group. Nevertheless, the XBP1 mRNA level was significantly upregulated in the LSC-ZnONPs group, but downregulated in the HSC-ZnONPs group, indicating multiple signal pathways involved in the apoptosis. In conclusion, a low concentration of MWCNTs (0.25 mg L-1) decreased the toxic effect of ZnONPs on common carp, but a high concentration of MWCNTs (2.5 mg L-1) enhanced it. This study will contribute to developing future risk assessment and management strategies for nanomaterials.

Polyethylene terephthalate nanoparticles induce oxidative damage in Chlorella vulgaris

Polyethylene Terephthalate (PET) is a type of plastic largely used for packing food and beverages. Unfortunately, it includes a major portion of the plastic distributed through aquatic systems wherever systematic collection and recycling are lacking. Although PET is known to be non-toxic, it is not obvious whether the nanoparticles (NPs) formed due to their degradation have any direct/indirect effect on aquatic organisms. In order to study the effects on aquatic environment, fresh water algae Chlorella vulgaris was subjected to incremental concentrations of the NPs. We observed a concentration and duration of exposure dependent decrease in algal growth rate along with reduced total chlorophyll content. Scanning electron microscopy revealed deformities in cell shape and the uptake of Propidium Iodide suggested membrane damage in response to NP exposure. Intracellular Reactive Oxygen Species level was also found significantly higher, evidenced by Dichlorodihydrofluorescein diacetate staining. Activity of antioxidant enzymes Superoxide dismutase (SOD), Peroxidase (POD) and Catalase (CAT) were significantly higher in the NP exposed groups suggesting the cellular response to regain homeostasis. Further, expression levels of the genes psaB, psbC, and rbcL associated with photosynthesis increased above two fold with respect to the control inferring the possibility of damage to photosynthesis and the initial molecular responses to circumvent the situation. In short, our studies provide evidence for oxidative stress mediated cellular damages in Chlorella vulgaris exposed to NPs of PET.

Integrated in silico analysis of transcriptomic alterations in nanoparticle toxicity across human and mouse models

Nanoparticles, due to their exceptional physicochemical properties are used in our day-to-day environment. They are currently not regulated which might lead to increased levels in the biological systems causing adverse effects. However, the overall mechanism behind nanotoxicity remains elusive. Previously, we analysed the transcriptome datasets of copper oxide nanoparticles using in silico tools and identified IL-17, chemokine signaling pathway, and cytokine-cytokine receptor interaction as the key pathways altered. Based on the findings, we hypothesized a common pathway could be involved in transition metal oxide nanoparticles toxicity irrespective of the variables. Further, there could be unique transcriptome changes between metal oxide nanoparticles and other nanoparticles. To accomplish this, the overall transcriptome datasets of nanoparticles consisting of microarray and RNA-Seq were obtained. >90 studies for 17 different nanoparticles, performed in humans, rats, and mice were assessed. After initial screening, 24 mouse studies (with 196 datasets) and 34 human studies (with 200 datasets) were used for further analyses. The common genes that are dysregulated upon NPs exposure were identified for human and mouse datasets separately. Further, an overrepresentation functional enrichment analysis was performed. The common genes, their gene ontology, gene-gene, and protein-protein interactions were assessed. The overall results suggest that IL-17 and its related pathways might be commonly altered in nanoparticle exposure with lung as one of the major organs affected.

Enhancement of Biological Nitrogen Removal System Resilience to Chronic Exposure of Zinc Oxide Nanoparticles by Quorum Sensing Modulation: Physiochemical, Microbial, and Metabolic Insights

The effects of three typical N-acyl-homoserine lactones (AHLs) on the tolerance of biological nitrogen removal (BNR) system to chronic exposure of zinc oxide nanoparticles (NPs) were investigated. C4-HSL successfully delayed the crash time of nitrogen removal performances in the NP-stressed system, while C6-HSL and C10-HSL maintained total nitrogen removal efficiencies throughout the 90-day NP exposure. All three AHLs increased NPs’ contents captured in extracellular polymeric substances, alleviating membrane damage and preserving floc structure. The activities of tricarboxylic acid cycle-related enzymes and the relative abundances of BNR-related functional genes and genera were significantly enhanced. Besides, C6-HSL and C10-HSL augmented antioxidant enzyme activities and the abundances of functional genes and metabolites related to antioxidation, flagellar assembly, and chemotaxis, which synergistically reduced the reactive oxygen species’ excessive accumulation. The tested AHLs effectively enhanced BNR systems’ tolerance to chronic NP exposure, providing inspiration for quorum sensing applications in emerging contaminant removal.

Nanoparticles and Airway Epithelial Cells: Exploring the Impacts and Methodologies in Toxicity Assessment.

The production of nanoparticles has recently surged due to their varied applications in the biomedical, pharmaceutical, textile, and electronic sectors. However, this rapid increase in nanoparticle manufacturing has raised concerns about environmental pollution, particularly its potential adverse effects on human health. Among the various concerns, inhalation exposure to nanoparticles poses significant risks, especially affecting the respiratory system. Airway epithelial cells play a crucial role as the primary defense against inhaled particulate matter and pathogens. Studies have shown that nanoparticles can disrupt the airway epithelial barrier, triggering inflammatory responses, generating reactive oxygen species, and compromising cell viability. However, our understanding of how different types of nanoparticles specifically impact the airway epithelial barrier remains limited. Both in vitro cell culture and in vivo murine models are commonly utilized to investigate nanoparticle-induced cellular responses and barrier dysfunction. This review discusses the methodologies frequently employed to assess nanoparticle toxicity and barrier disruption. Furthermore, we analyze and compare the distinct effects of various nanoparticle types on the airway epithelial barrier. By elucidating the diverse responses elicited by different nanoparticles, we aim to provide insights that can guide future research endeavors in assessing and mitigating the potential risks associated with nanoparticle exposure.

Amino-modified nanoplastics at predicted environmental concentrations cause transgenerational toxicity through activating germline EGF signal in Caenorhabditis elegans

In the real environment, some chemical functional groups are unavoidably combined on the nanoplastic surface. Reportedly, amino-modified polystyrene nanoparticles (PS-A NPs) exposure in parents can induce severe transgenerational toxicity, but the underlying molecular mechanisms remain largely unclear. Using Caenorhabditis elegans as the animal model, this study was performed to investigate the role of germline epidermal growth factor (EGF) signal on modulating PS-A NPs' transgenerational toxicity. As a result, 1–10 μg/L PS-A NPs exposure transgenerationally enhanced germline EGF ligand/LIN-3 and NSH-1 levels. Germline RNAi of lin-3 and nsh-1 was resistant against PS-A NPs' transgenerational toxicity, implying the involvement of EGF ligand activation in inducing PS-A NPs' transgenerational toxicity. Furthermore, LIN-3 overexpression transgenerationally enhanced EGF receptor/LET-23 expression in the progeny, and let-23 RNAi in F1-generation notably suppressed PS-A NPs' transgenerational toxicity in the exposed worms overexpressing germline LIN-3 at P0 generation. Finally, LET-23 functioned in neurons and intestine for regulating PS-A NPs' transgenerational toxicity. LET-23 acted at the upstream DAF-16/FOXO within the intestine in response to PS-A NPs' transgenerational toxicity. In neurons, LET-23 functioned at the upstream of DAF-7/DBL-1, ligands of TGF-β signals, to mediate PS-A NPs' transgenerational toxicity. Briefly, this work revealed the exposure risk of PS-A NPs' transgenerational toxicity, which was regulated through activating germline EGF signal in organisms.

Performance enhancement of rechargeable zinc-air battery through synergistic ex-solution of multi-component Pt/CoWO4-x catalysts

Advancing zinc-air battery (ZAB) technology necessitates the development of air cathode electrocatalyst systems that demonstrate high reactivity and stability. We introduce a novel method to fabricate a robust catalyst-support hybrid. This hybrid comprises Co-doped Pt nanoparticles (NPs) anchored on metal oxide (Ex-PtCoWO) nanofibers (NFs), synthesized via electrospinning followed by selective metal ex-solution. Controlling the ex-solution of metal NPs leads to a highly active and stable oxygen reduction reaction (ORR). Moreover, the three-dimensional CoWO4-x NFs network enhances the surface exposure of ex-solved metal NPs, thereby aiding both selective ex-solution and the provision of active sites for the oxygen evolution reaction (OER) during ZAB recharge. The Ex-PtCoWO NF exhibits an ORR half-wave potential of 0.89 V and an OER potential of 1.69 V at 10 mA cm−2 in alkaline media. ZABs utilizing Ex-PtCoWO NF show an extended cycle life of over 240 h with reduced charge-discharge polarization, compared to commercial catalysts.

Behavioral, biochemical, histopathological evaluation and gene expression of brain injury induced by nanoceria injected intranasal or intraperitoneal in mice.

Nanotechnology has shown a remarkable progress nevertheless, there is a growing concern about probable neurotoxic and neurodegenerative effects due to NPs exposure. Various toxicological and epidemiological studies reported that the brain is a main target for ultrafine particles. Brain inflammation is considered as a possible mechanism that can participate to neurotoxic and neurodegenerative effects. Whether nanoparticles (NPs) may produce neurotoxicity and promote neurodegenerative is largely unstudied. The present study was done to investigate whether intranasal and intra-peritoneal exposure to cerium oxide nanoparticles (CeO2NPs, nanoceria (NC)) could cause neurotoxicity and neurodegenerative changes in the brain tissue through conducting some behavioral tests, biochemical evaluation, histopathological examinations of brain hippocampus and gene expressions. Fifteen mice were separated into 3 equal groups. In group (I) "control group", mice were received distilled water orally and kept as a control group. Mice in the group (II) "NC I/P group" were injected i.p with cerium oxide nanoparticles at a dose of 40 mg/kg b.wt, twice weekly for 3 weeks. In group (III) "NC I/N group" mice were received nanoceria intranasally (40 mg/kg b.wt), twice weekly for 3 weeks. Exposure to nanceria resulted in oxidative damage in brain tissue, a significant increase in malondialdehyde (MDA) and acetylcholinestrase (AchE) levels, significant decrease in reduced glutathione (GSH) concentration, upregulation in the apoptosis-related genes (c-Jun: c-Jun N-terminal kinases (JNKs), c-Fos: Fos protooncogene, AP-1 transcription factor subunit, c-Myc: c-myelocytomatosis oncogene product or MYC protooncogene, bHLH transcription factor), locomotor and cognitive impairment in mice but the effect was more obvious when nanoceria adminstred intraperitoneally. Nanoceria cause oxidative damage in brain tissue of mice when adminstred nanoceria intraperitoneally more than those received nanoceria intranasal.

Foraminiferal detoxification breakdown induced by fatal levels of TiO2 nanoparticles

The increase discharge of titanium dioxide (TiO2) nanoparticles, derived from engineered material waste, exerts a detrimental impact on both the marine ecosystem and public health. The cytotoxicity of TiO2 nanoparticles on marine organisms should be imperatively understood to tackle the urgent concern for the well-being of marine life. Various concentrations of TiO2 nanoparticles have proven to reach fatal levels in aquatic organisms, requiring a deeper exploration of cytotoxicity. Notably, certain benthic foraminifers, such as Ammonia veneta, have been identified as capable of incorporating TiO2 nanoparticles into vesicles. However, these organisms exhibit a detoxification mechanism through exocytosis, as indicated by previous transcriptomic inferences. This presents the advantage of assessing the tolerance of foraminifers to TiO2 nanoparticles as pollutants and investigating the long-term effects of cytotoxicity. In this study, we scrutinized the distribution of TiO2 nanoparticles within cells and the growth rates of individuals in seawater media containing 1, 5, 10, and 50 ppm TiO2 nanoparticles, comparing the results with a control group over a 5-week period, utilizing A. veneta stain. Transmission electron microscopy observations consistently revealed high concentrations of TiO2 nanoparticles in vesicles, and their expulsion from cells was evident even with exposure to 5 ppm TiO2 nanoparticles. Under the control and 1 ppm TiO2 conditions, foraminifers increased their cell volume by adding a calcification chamber to their tests every 1 or 2 days. However, the 5-week culturing experiments demonstrated that foraminifers gradually ceased growing under 5 ppm TiO2 nanoparticle exposure and exhibited no growth at > 10 ppm concentrations, despite an ample food supply. Consequently, these findings with A. veneta suggest that the foraminiferal detoxification system could be disrupted by concentrations exceeding 5 ppm of TiO2 nanoparticles. The toxic effect of TiO2 nanoparticles on meiofauna, such as benthic foraminifers, have been poorly understood, though these organisms play an important role in the marine ecosystem. Environmental accumulation of TiO2 nanoparticles on the coast has already exceeded twenty times more than foraminiferal detoxification level. Future studies focusing on toxic mechanism of TiO2 nanoparticles are crucial to prevent the breakdown of the marine ecosystem through accelerating discharge of TiO2 nanoparticles into the ocean.

Novel fluorinated MIL-88B assisted hydrogen-bonded organic framework derived high efficiency oxygen reduction catalyst in microbial fuel cell

The crux to promote the utilization of air-cathode microbial fuel cell (AC-MFC) is to find high-efficiency and low-budget oxygen reduction reaction (ORR) catalysts, which can replace Pt-based catalysts, reduce electrode cost and thus improve the cost-effectiveness of AC-MFC. In this work, a three-dimensional network carbon structure F-MIL-HOF loaded with Fe2O3 material composites have been successfully synthesized by carbonizing by NH4F-fluorinated MIL-88B combined with a high nitrogen content hydrogen-bonded organic framework (HOF) to evince excellent catalytic property for ORR in both alkaline and neutral electrolytes. The Fe2O3 obtained after carbonization of MIL-88B portrays efficient ORR catalytic activity, and the combination with the natural pore-rich HOF precisely solves the problems of uncontrolled growth and agglomeration during Fe2O3 synthesis, achieving the high dispersion and full exposure of Fe2O3 nanoparticles as active sites. As-synthesized F-MIL-HOF as cathodic catalyst reaches a limiting current density of 6.40 mA cm−2 in alkaline condition, which exhibits an advantage performance over commercial Pt/C (6.26 mA cm−2). Furthermore, F-MIL-HOF shows approximately four-electron pathway with better methanol resistance and stability than Pt/C, and the performance only decreases by 10.2 % in the stability test, which still had efficient ORR catalytic performance. F-MIL-HOF is an emerging alternative electro-catalyst for AC-MFC.

Template-assisted growth of Ga-based nanoparticle clusters on Si: effect of post-annealing process on the Ga ion beam exposed 2D arrays fabricated by focused ion beam nanolithography

We demonstrate template-assisted growth of gallium-based nanoparticle clusters on silicon substrate using a focused ion beam (FIB) nanolithography technique. The nanolithography counterpart of the technique steers a focussed 30 kV accelerated gallium ion beam on the surface of Si to create template patterns of two-dimensional dot arrays. Growth of the nanoparticles is governed by two vital steps namely implantation of gallium into the substrate via gallium beam exposure and formation of the stable nanoparticles on the surface of the substrate by subsequent annealing at elevated temperature in ammonia atmosphere. The growth primarily depends on the dose of implanted gallium which is in the order of 107 atoms per spot and it is also critically influenced by the temperature and duration of the post-annealing treatment. By controlling the growth parameters, it is possible to obtain one particle per spot and particle densities as high as 109 particles per square centimetre could be achieved in this case. The demonstrated growth process, utilizing the advantages of FIB nanolithography, is categorized under the guided organization approach as it combines both the classical top-down and bottom-up approaches. Patterned growth of the particles could be utilized as templates or nucleation sites for the growth of an organized array of nanostructures or quantum dot structures.

Nanoparticles and root traits: mineral nutrition, stress tolerance and interaction with rhizosphere microbiota.

This review article highlights a broader perspective of NPs and plant-root interaction by focusing on their beneficial anddeleterious impacts on root system architecture (RSA). The root performs a vital function by securing itself in the soil, absorbing and transporting water and nutrients to facilitate plant growth and productivity. In dicots, the architecture of the root system (RSA) is markedly shaped by the development of the primary root and its branches, showcasing considerable adaptability in response to changes in the environment. For promoting agriculture and combating global food hunger, the use of nanoparticles (NPs) may be an exciting option, for which it is essential to understand the behaviour of plants under NPs exposure. The nature of NPs and their physicochemical characteristics play a significant role in the positive/negative response of roots and shoots. Root morphological features, such as root length, root mass and root development features, may regulated positively/negatively by different types of NPs. In addition, application of NPs may also enhance nutrient transport and soil fertility by the promotion of soil microorganisms including plant growth-promoting rhizobacteria (PGPRs) and also soil enzymes. Interestingly the interaction of nanomaterials (NMs) with rhizospheric bacteria can enhance plant development and soil health. However, some studies also suggested that the increased use of several types of engineered nanoparticles (ENPs) may disrupt the equilibrium of the soil-root interface and unsafe morphogenesis by causing the browning of roots and suppressing the growth of root and soil microbes. Thus, this review article has sought to compile a broader perspective of NPs and plant-root interaction by focusing on their beneficial or deleterious impacts on RSA.

Effect of titanium dioxide nanoparticle (TiO2-NP) exposure in a novel Amur sturgeon Acipenser schrenckii hepatocyte cell line.

In vitro cell culture is crucial for predicting the toxicity of titanium dioxide nanoparticle (TiO2-NP). However, assessing the toxicity of TiO2-NPs in sturgeon remains difficult given the lack of sufficient cell lines. We established and characterized the first hepatocyte cell line from Acipenser schrenckii liver tissue (ASL). This ASL cell line proliferated well in Dulbecco's modified Eagle's medium at 25°C and 10% fetal bovine serum. ASL cells with a chromosome number of 244 were successfully transfected with the pEGFP-N3 plasmid. The ASL cell line's origin was verified as A. schrenckii through mitochondrial cytochrome C oxidase I and mitochondrial 16S ribosomal RNA (rRNA) sequencing. Using the ASL cell line as an in vitro model, we found that TiO2-NP exposure decreased the viability and promoted the damage of ASL cells (96-h LC50 = 331.8 μg mL-1). Increased reactive oxygen species and malondialdehyde levels in ASL cells suggested oxidative stress under TiO2-NP exposure. We also observed dysregulation of aspartate aminotransferase and alanine aminotransferase levels. By detecting calcium ions and mitochondrial membrane potential indicators, we found that the apoptotic pathway induced by endoplasmic reticulum stress played a major role at low concentrations of TiO2-NP-induced stress. Both mitochondria-mediated and endoplasmic reticulum stress promoted apoptosis under increasing TiO2-NP concentrations. In conclusion, the ASL cell line established in this study is a useful in vitro model for toxicological studies of TiO2-NP exposure in fish.

Assessing the chronic exposure of copper oxide and zinc oxide nanoparticles in zebrafish

Assessing the chronic exposure of copper oxide and zinc oxide nanoparticles in zebrafish

Harnessing Fe3O4 nanoparticles for sustainable harvesting of astaxanthin-producing microalgae: Advancing industrial-scale biorefinery

Microalgae are esteemed for their potential as sustainable sources of bioactive compounds, notably astaxanthin, a valuable antioxidant with diverse health applications. This study investigates Fe3O4 nanoparticle efficacy in harvesting astaxanthin-producing microalgae for sustainable applications. Parameters such as nanoparticle concentration, exposure time, and magnetic field strength were optimized for Haematococcus pluvialis and Chlorella zofingiensis biomass harvesting. Fe3O4 nanoparticles achieved >99% harvesting efficiency in H. pluvialis at 200 mg L-1 across all pH ranges, while C. zofingiensis showed peak efficiency at 800 mg L-1 and pH 4. The zeta analyzer revealed a maximum potential gap at pH 4, facilitating stable binding of microalgae with nanoparticles. This research underscores Fe3O4 nanoparticles’ sustainable harvesting potential, aligning with Sustainable Development Goals SDGs such as Industry, Innovation, and Infrastructure (SDG 9) and Responsible Consumption and Production (SDG 12). It offers a promising pathway for industrial-scale microalgae production and astaxanthin exploitation, with implications for biorefinery development, and commercialization in pharmaceuticals, nutraceuticals, and cosmetics industries.

Cytotoxicity and Antioxidant Defences in Euplotes aediculatus Exposed to Single and Binary Mixtures of Heavy Metals and Nanoparticles

The aim of this study was to analyse the cytotoxicity of heavy metals (HMs) and nanoparticles (NPs) on populations of the ciliated protist Euplotes aediculatus. We used ecotoxicological tests, antioxidant assays, and the MixTOX tool in Microsoft® Excel to evaluate the toxic effect of HMs and NPs in single and binary mixtures on E. aediculatus and to detect the type of interaction between them. Based on our results, the order of toxicity was Cu > Cd >> Zn (1 h and 24 h) for HMs and ZnO > CuO >> TiO2 >> SiO2 (1 h) and CuO > ZnO >> TiO2 >> SiO2 (24 h) for NPs. The interaction between metals in binary mixtures was predominantly synergistic at low doses and antagonistic at high doses. The type of interaction depende on the metals present and their respective concentrations. Furthermore, both HMs and NPs were shown to trigger effective antioxidant responses in E. aediculatus. Our research highlights the importance of considering the combined effects of HMs and NP exposure and their potency in risk assessment.

Antimicrobial efficiency against fish pathogens on the green synthesized silver nanoparticles

Fish-borne pathogens such as A. hydrophila and F. aquidurense are the most resistant strains in pisciculture farming. Removing the aforementioned pathogens without antibiotics presents a formidable challenge. To overcome this problem, silver nanoparticles (AgNPs) are synthesized using silver nitrate, water medium, and as an AzadirachtaIndica leaf extract via the green synthesis route. X-ray diffraction (XRD) pattern results authenticate the synthesized material is the face-centered cubic structure of silver. The optical absorption edge of the synthesized product was found at the wavelength of 440 nm from the UV–visible spectra, which is confirmed to relate to the Surface Plasmon Resonance peaks of silver particles. In addition, the optical band gap value of the synthesized Ag sample is measured to be 2.81 eV from the obtained optical absorption spectra. EDX spectrum of the synthesized product also supports confirming the silver particle formation. The FT-IR spectra of the neem extract and silver nanoparticles showed their characteristic functional groups, respectively. The presence of bands between 1000 cm−1 to 500 cm−1 indicates to the formation of silver particles. Spherical particles appeared in the synthesized Ag using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The particle size of Ag NPs was measured as 40 nm and 62 ± 10 nm by TEM and Dynamic Light Scattering (DLS). The zeta potential was also measured as −12 mV showing the synthesized sample's stable nature. Using the DPPH assay, synthesized AgNPs were taken along with the various concentrations of ascorbic acid (20, 40, 60, 80, and 100 μg/mL) to examine the free radical scavenging activity (RSA). RSA value is higher (84 ± 2 %) for synthesized AgNPs at higher concentration (100 μg/mL) than 21 ± 2 % at low concentration (100 μg/mL). The antimicrobial efficacy of the AgNPs against A. hydrophila and F. aquidurense was performed through the agar diffusion method and its results showed the inhibitory zones of the F.aquidurense and A. hydrophila were measured as 25 ± 3 mm, and 28 ± 4 mm respectively. The synthesized Ag particles showed excellent antimicrobial and antioxidant properties confirmed by antimicrobial and DPPH experiments. It implies that the green synthesized silver nanoparticles could be a good alternative for antibiotics in aquaculture farms. The exposure of low concentrations of silver nanoparticles to zebrafish and brine shrimp does not affect the viability and morphology. The exposure of silver nanoparticles in the fisheries in optimized concentration and time could control the fish-borne pathogens without antibiotics.