ABSTRACT
The on-going anthropogenic degradation of freshwater habitats has drastically altered the environmental supply of both nutrients and common pollutants. Most organisms living in these altered habitats experience interactive effects of various stressors that can initiate adjustments at multiple levels impacting their fitness. Hence, studies measuring response to a single environmental parameter fail to capture the complexities of the status quo. We tested both the individual and the interactive effect of arsenic (As) exposure, food quantity, and dietary phosphorus (P)-supply on six life-history traits (Juvenile Growth Rate; Adult Growth Rate; Age and Size at Maturity, Lifespan, and Fecundity) as surrogates for organismal fitness in the keystone aquatic grazer Daphnia pulex. We also tested the effect of food quantity and P-supply on somatic As accumulation in Daphnia. Our results indicated an influence of P-supply on neonatal growth and an influence of As and food quantity on growth and maintenance later in life. Maturation was strongly influenced by all three variables, with no reproduction observed in the presence of two or more environmental stressors. We found a strong interaction between As and dietary P, with increased P-supply intensifing the toxicity effect of As. No such effects were seen between As and food quantity, indicating a differential role of quantity versus quality on As toxicity. We found a nominal effect of diet on somatic As accumulation. The results from the present study emphasize the importance of considering such interactions between co-occurring environmental stressors and the dietary status of organisms, to better predict and manage impacts and risks associated with common environmental toxicants in highly vulnerable ecosystems. Environ Toxicol Chem 2024;43:1807-1819. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Subject(s)
Arsenic , Daphnia , Phosphorus , Water Pollutants, Chemical , Animals , Daphnia/drug effects , Water Pollutants, Chemical/toxicity , Arsenic/toxicity , Phosphorus/toxicity , Reproduction/drug effects , Daphnia pulexABSTRACT
La ingesta de petardo supone un riesgo potencial para la vida del paciente si este contiene el compuesto tóxico denominado fósforo amarillo (FA). Afortunadamente, dicho material no es utilizado actualmente en nuestro país para la fabricación de productos de pirotecnia, no siendo así en otras regiones del mundo como Asia o América Latina. La ingesta de FA puede causar el fallecimiento del paciente hasta en un 20-50% de los casos por acumulación tóxica en el organismo, produciendo fundamentalmente fallo hepático y, consecuentemente, fallo multiorgánico. Los petardos en España contienen materiales no tóxicos para el organismo, por lo que su ingesta puede producir náuseas y molestias abdominales, pero no un riesgo letal para el paciente. (AU)
The ingestion of firecrackers poses a potential risk to the patient's life if they contain the toxic component called yellow phosphorus (YFP). Fortunately, this material is not currently used in our country for the manufacture of pyrotechnic products, but this is not the case in other regions of the world such as Asia or Latin America. The ingestion of YFP can cause the death of up to 20-50% of cases, by toxic accumulation in the organism, producing mainly hepatic failure and consequently multiorgan failure. Firecrackers in Spain contain non-toxic materials for the organism, so their ingestion may cause nausea and abdominal discomfort, but not a lethal risk for the patient. (AU)
Subject(s)
Humans , Adolescent , Foreign Bodies/diagnostic imaging , Poisoning/diagnostic imaging , Phosphorus/toxicity , SpainABSTRACT
The aim of this article is to stimulate interest and discussion on the pathogenesis of 'phossy jaw'. Historical evidence from newspapers and articles of the time is presented, as other scientific evidence is largely absent. It has stimulated considerable interest in present-day media due to the struggles of nineteenth century reformers to improve working conditions against an apathetic government and weak enforcement of regulation. Those afflicted were often young women who suffered severe pain, loss of segments of jaw, and disfigurement.
Subject(s)
Jaw Diseases , Pain , Phosphorus , Female , Humans , Phosphorus/toxicity , Jaw Diseases/chemically inducedABSTRACT
Phosphorus (P) deficiency tolerance in rice is a complex character controlled by polygenes. Through proteomics analysis, we could find more low P tolerance related proteins in unique P-deficiency tolerance germplasm Dongxiang wild rice (Oryza Rufipogon, DXWR), which will provide the basis for the research of its regulation mechanism. In this study, a proteomic approach as well as joint analysis with transcriptome data were conducted to identify potential unique low P response genes in DXWR during seedlings. The results showed that 3589 significant differential accumulation proteins were identified between the low P and the normal P treated root samples of DXWR. The degree of change was more than 1.5 times, including 60 up-regulated and 15 downregulated proteins, 24 of which also detected expression changes of more than 1.5-fold in the transcriptome data. Through quantitative trait locus (QTLs) matching analysis, seven genes corresponding to the significantly different expression proteins identified in this study were found to be uncharacterized and distributed in the QTLs interval related to low P tolerance, two of which (LOC_Os12g09620 and LOC_Os03g40670) were detected at both transcriptome and proteome levels. Based on the comprehensive analysis, it was found that DXWR could increase the expression of purple acid phosphatases (PAPs), membrane location of P transporters (PTs), rhizosphere area, and alternative splicing, and it could decrease reactive oxygen species (ROS) activity to deal with low P stress. This study would provide some useful insights in cloning the P-deficiency tolerance genes from wild rice, as well as elucidating the molecular mechanism of low P resistance in DXWR.
Subject(s)
Heat-Shock Proteins/metabolism , Oryza/metabolism , Phosphorus/toxicity , Plant Proteins/metabolism , Proteome/analysis , Seedlings/metabolism , Stress, Physiological , Gene Expression Regulation, Plant , Heat-Shock Proteins/genetics , Oryza/drug effects , Oryza/genetics , Oryza/growth & development , Plant Proteins/genetics , Proteome/metabolism , Proteomics , Quantitative Trait Loci , Seedlings/genetics , Seedlings/growth & development , Seedlings/toxicity , TranscriptomeABSTRACT
Black phosphorus (BP) nanosheet is easily oxidized by oxygen and water under ambient environment, thus, reliable BP passivation techniques for biomedical applications is urgently needed. A simple and applicable passivation strategy for biomedical applications was established by encapsulating BP nanosheet into zeolitic imidazole framework-8 (ZIF-8). The resulted BP nanosheet in ZIF-8 (BP@ZIF-8) shows not only satisfied chemical stability in both water and phosphate buffered saline (PBS), but also excellent biocompatibility. Notably, BP nanosheet endows the prepared BP@ZIF-8 with prominent photothermal conversion efficiency (31.90%). Besides passivation BP, ZIF-8 provides the BP@ZIF-8 with high drug loading amount (1353.3 mg g-1). Moreover, the loaded drug can be controlled release by pH stimuli. Both in vitro and in vivo researches verified the resulted BP@ZIF-8 an ideal candidate for tumor multimodal treatments.
Subject(s)
Antineoplastic Agents/therapeutic use , Drug Carriers/chemistry , Metal-Organic Frameworks/chemistry , Nanostructures/chemistry , Neoplasms/drug therapy , Phosphorus/chemistry , Animals , Antineoplastic Agents/chemistry , Cell Line, Tumor , Combined Modality Therapy , Doxorubicin/chemistry , Doxorubicin/therapeutic use , Drug Carriers/radiation effects , Drug Carriers/toxicity , Drug Liberation , Drug Therapy , Female , Humans , Hydrogen-Ion Concentration , Infrared Rays , Metal-Organic Frameworks/radiation effects , Metal-Organic Frameworks/toxicity , Mice , Nanostructures/radiation effects , Nanostructures/toxicity , Phosphorus/radiation effects , Phosphorus/toxicity , Photothermal TherapyABSTRACT
Our previous study showed that bone marrow mesenchymal stem cell derived exosomes (BMSC-Exos) suppress high phosphorus (Pi)-induced calcification of vascular smooth muscle cells (VSMCs). However, the mechanism had remained unclear. This study aimed to investigate the mechanism by which BMSC-Exos inhibit vascular calcification (VC). We found that BMSC-Exos reduced high Pi-induced Runx2, osteocalcin and BMP2 expression and inhibited the calcium deposition. Gene expression of human VSMCs stimulated by Pi or Pi plus BMSC-Exos (Pi + Exo) was systematically examined by microarray technology. NONHSAT 084969.2 and transcription factor p65 expression was significantly lower in the Pi + Exo group compared with the Pi group. This finding indicated that NONHSAT 084969.2 and the nuclear factor-κB pathway might play an important role in VC inhibition by BMSC-Exos. By silencing NONHSAT 084969.2 with small interfering RNA, Runx2, BMP2, and osteocalcin expression was decreased significantly. The calcified nodule content and alkaline phosphatase activity were reduced after NONHSAT 084969.2 inhibition and p65, p50, and IκB kinase-α expression was decreased significantly. These results indicated that BMSC-Exos inhibited Pi-induced transdifferentiation and calcification of VSMCs by regulating the NONHSAT 084969.2/nuclear factor-κB axis.
Subject(s)
Exosomes/metabolism , Mesenchymal Stem Cells/metabolism , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/metabolism , NF-kappa B/metabolism , Phosphorus/toxicity , RNA, Long Noncoding/metabolism , Vascular Calcification/genetics , Cell Line , Cell Transdifferentiation/drug effects , Cluster Analysis , Down-Regulation/drug effects , Down-Regulation/genetics , Exosomes/ultrastructure , Gene Expression Profiling , Humans , Minerals/metabolism , Myocytes, Smooth Muscle/drug effects , RNA, Long Noncoding/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Signal Transduction/drug effects , Vascular Calcification/pathologyABSTRACT
Biogenic phosphorus (P) based - nanomaterials (NMs) are currently being explored as nanofertilizers. In this study, the acute toxic effects and trophic transfer of multiple types of P-based NMs were examined on soil-dwelling nematode, Caenorhabditis elegans. The study involved four variants of nanohydroxyapatites (nHAPs) synthesized either via a biogenic or a chemical route and another NM, nanophosphorus (nP), biosynthesized from bulk rock phosphate (RP). The pristine NMs differed in their physicochemical properties with each possessing different shapes (biogenic nHAP: platelet-shaped, Ë35 nm; biogenic nP, Ë5-10 nm: dots; chemically synthesized nHAPs: spherical, Ë33 nm, rod, Ë80 nm and needle-shaped, Ë64 nm). The toxic effects of NMs' in C. elegans were assessed using survival, hatching and reproductive cycle as the key endpoints in comparison to bulk controls, calcium phosphate and RP. The interactions and potential uptake of fluorescent-tagged nHAP to E. coli OP50 and C. elegans were investigated using confocal microscopy. The transformation of NMs within the nematode gut was also explored using dynamic light scattering and electron microscopy. C. elegans exposed to all of the variants of nHAP and the nP had 88-100% survival and 82-100% hatch rates and insignificant effects on brood size as observed at the tested environmentally relevant concentrations ranging from 5 to 100 µg.mL-1. Confocal microscopy confirmed the interaction and binding of fluorescent-tagged nHAP with the surface of E. coli OP50 and their trophic transfer and internalization into C. elegans. Interestingly, there was only a small reduction in the hydrodynamic diameter of the nHAP after their uptake into C. elegans and the transformed NMs did not induce any additional toxicity as evident by healthy brood sizes after 72 h. This study provides key information about the environmental safety of agriculturally relevant P-based NMs on non-target species.
Subject(s)
Caenorhabditis elegans , Nanostructures , Animals , Escherichia coli/metabolism , Nanostructures/toxicity , Phosphorus/toxicity , Soil/chemistryABSTRACT
Ectopic calcification is a risk of cardiovascular disease in chronic kidney disease (CKD) patients, and impaired endothelial nitric oxide synthase (eNOS) is involved in the CKD complications. However, whether eNOS dysfunction is a cause of ectopic calcification in CKD remains to be elucidated. To address this issue, we investigated the role of eNOS in ectopic calcification in mice with renal injury caused by an adenine and high-phosphorus (Ade + HP) diet. DBA/2J mice, a calcification-sensitive strain, were fed Ade + HP for 3 weeks. Expression levels of eNOS-related genes were reduced significantly in their calcified aorta. C57BL/6J is a calcification-resistant strain, and wild-type mice showed mild calcified lesions in the aorta and kidney when given an Ade + HP diet for 4 weeks. In contrast, a lack of eNOS led to the development of severe aortic calcification accompanied by an increase in runt-related transcription factor 2, an osteochondrogenic marker. Increased renal calcium deposition and the tubular injury score were remarkable in mice lacking eNOS-fed Ade + HP. Exacerbation of ectopic calcification by a lack of eNOS is associated with increased oxidative stress markers such as nicotinamide adenine dinucleotide phosphate oxidases. In conclusion, eNOS is critically important in preventing ectopic calcification. Therefore, the maintenance of eNOS is useful to reduce cardiovascular disease events and to improve prognosis in CKD patients.
Subject(s)
Aorta/pathology , Calcinosis/enzymology , Nitric Oxide Synthase Type III/metabolism , Renal Insufficiency, Chronic/complications , Adenine/toxicity , Animals , Diet/adverse effects , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Phosphorus/toxicity , Renal Insufficiency, Chronic/chemically induced , Uremia/etiologyABSTRACT
Black phosphorus quantum dots (BP-QDs) are a new type of zero-dimensional (0D) nanomaterial that has been widely used due of their superior properties in many biomedical fields, but limited studies have focused on the biocompatibility of BP-QDs, particularly in the respiratory system. In this study, we investigated the potential lung cell toxicity of BP-QDs in vitro. Two human lung-derived cells, A549 and Beas-2B, were treated with 5â¼20 µg/mL BP-QDs for 24 h. The results showed that BP-QDs triggered significant lung cell toxicity, including a dose-dependent decrease in cell viability, lactate dehydrogenase (LDH) leakage, cell shape changes, cellular oxidative stress and cell cycle arrest. In addition, pretreatment with the classical phagocytosis inhibitor cytochalasin D (Cyto D) alleviated the decrease in cell viability and LDH leakage induced by BP-QDs. In contrast, BP-QDs induced the production of cellular reactive oxygen species (ROS) and decreases in the glutathione level, whereas the ROS scavenger N-acetyl-L-cysteine (NAC) could protect A549 and Beas-2B cells from BP-QD-induced cellular oxidative stress. Taken together, the results from this study indicate that the potential toxic effects and mechanisms of BP-QDs in two different human lung cells should be considered to evaluate the lung cell safety of BP-QDs.
Subject(s)
Phosphorus , Quantum Dots , Cell Survival , Humans , Lung , Phosphorus/toxicity , Quantum Dots/toxicity , Reactive Oxygen SpeciesABSTRACT
The effect of nanomaterials aging, namely the transformation of comprehensive characteristics after experiencing real or complex environmental behaviors, on their ecotoxicology is still lacking. Moreover, the mechanisms by which NPs influence biological phosphorus (P) removal during sewage treatment require further elucidation. Therefore, we used both pristine and aged anatase (TiO2-A) and rutile (TiO2-R) NPs to investigate the mechanisms by which NPs affect P removal in a SBR. At 0.1 mg/L, the four types of NPs (pristine and aged) had no significant effect on sludge purification after acute (72-h) exposure under simulated sunlight. However, at 50 mg/L-regardless of the crystalline phase of the NPs-SOP and COD removal efficiency dropped steeply to approximately 42.2-82.4 % (p < 0.05) and 69.8-83.3 % (p < 0.05), respectively, especially in the pristine TiO2-NPs groups because of decrease of richness and diversity of genus level of PAOs and enzyme activity of both PPK and PPX, and the sluggish transformation of PHA and glycogen. Aging reduced the ability of NPs toxicity. The toxicity mechanisms of TiO2-NPs included lipid peroxidation and contact damage, or leakage from bacterial cytoplasmic membrane, which are closely related to photooxidation capacity and aqueous solution stability-i.e., nanoscale effects-and the impacts of aging or inclusion.
Subject(s)
Metal Nanoparticles , Nanoparticles , Nanoparticles/toxicity , Phosphorus/toxicity , Sewage , Titanium/toxicityABSTRACT
Novel colorimetric and ratiometric fluorometric dual-mode N, P-co-doped carbon nanodots, BPEI-CDs, for highly sensitive and selective detection of formaldehyde (FA) were successfully prepared from N-(phosphonomethyl)iminodiacetic acid (PMIDA) and branched polyethyleneimine (BPEI). The treatment of FA caused a remarkable linear enhancement of ratiometric fluorescence (F501 nm/F408 nm) in a wide range of 0-40 µM with a detection limit (LOD) of 0.47 µM (3σ/k), along with distinct color changes from colorless to light yellow. Mechanistic study shows that this electron-rich system, formed by the cooperative roles of N and P, promoted the FA-induced Schiff bases formation reaction, which contributed to the CD aggregation-induced emission (AIE) "turn-on" response and enhancement of π-conjugation-induced bathochromic behaviors. Furthermore, N, P-co-doped BPEI-CDs were successfully applied to the determination of FA in bean sprout samples. Using the standard addition method, the recoveries ranged from 96.9 to 101.8%, and the relative standard deviation (RSD) was in the range 2.23 to 3.21%. The application for intracellular FA sensing further verified that this novel nanoprobe may offer a new venue for the design of simple, low-cost, and sensitive biosensors. Graphical abstract.
Subject(s)
Colorimetry/methods , Fluorescent Dyes/chemistry , Formaldehyde/analysis , Quantum Dots/chemistry , Spectrometry, Fluorescence/methods , Carbon/chemistry , Carbon/toxicity , Cell Line, Tumor , Fluorescence , Fluorescent Dyes/toxicity , Humans , Limit of Detection , Microscopy, Confocal , Microscopy, Fluorescence , Nitrogen/chemistry , Nitrogen/toxicity , Phosphorus/chemistry , Phosphorus/toxicity , Quantum Dots/toxicity , Seedlings/chemistryABSTRACT
Phosphorus (P) is an essential mineral nutrient for plants. Nevertheless, excessive P accumulation in leaf mesophyll cells causes necrotic symptoms in land plants; this phenomenon is termed P toxicity. However, the detailed mechanisms underlying P toxicity in plants have not yet been elucidated. This study aimed to investigate the molecular mechanism of P toxicity in rice. We found that under excessive inorganic P (Pi) application, Rubisco activation decreased and photosynthesis was inhibited, leading to lipid peroxidation. Although the defence systems against reactive oxygen species accumulation were activated under excessive Pi application conditions, the Cu/Zn-type superoxide dismutase activities were inhibited. A metabolic analysis revealed that excessive Pi application led to an increase in the cytosolic sugar phosphate concentration and the activation of phytic acid synthesis. These conditions induced mRNA expression of genes that are activated under metal-deficient conditions, although metals did accumulate. These results suggest that P toxicity is triggered by the attenuation of both photosynthesis and metal availability within cells mediated by phytic acid accumulation. Here, we discuss the whole phenomenon of P toxicity, beginning from the accumulation of Pi within cells to death in land plants.
Subject(s)
Oryza/metabolism , Phosphorus/toxicity , Phytic Acid/metabolism , Plant Leaves/metabolism , Ribulose-Bisphosphate Carboxylase/metabolism , Ascorbate Peroxidases/metabolism , Chloroplasts/drug effects , Chloroplasts/metabolism , Cytosol/drug effects , Cytosol/metabolism , Enzyme Activation/drug effects , Gene Expression Regulation, Plant/drug effects , Oryza/drug effects , Phosphorus/metabolism , Photosynthesis/drug effects , Photosynthesis/physiology , Plant Leaves/drug effects , Plant Proteins/metabolism , Reactive Oxygen Species/metabolism , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolismABSTRACT
Various types of photodynamic agents have been explored for photodynamic therapy (PDT) to destroy cancers located in deep tissues. However, these agents are generally limited by low singlet oxygen (1O2) yields owing to weak absorption in the optical transparent window of biological tissues. Accordingly, in this work, we developed a nanocomposite through the assembly of gold nanobipyramids (GNBPs) on black phosphorus nanosheets (BPNSs). This nanocomposite could simultaneously enhance 1O2 generation and hyperthermia by localized surface plasmon resonance in cancer therapy. As two-dimensional inorganic photosensitizers, BPNSs were hybridized with GNBPs to form BPNS-GNBP hybrid nanosheets. The hybridization markedly increased 1O2 production by the BPNSs through plasmon-enhanced light absorption. The nanocomposite exhibited a higher photothermal conversion efficiency than the BPNSs alone. In vitro and in vivo assays indicated that the BPNS-GNBP hybrid nanocomposite exhibited good tumor inhibition efficacy owing to simultaneous dual-modality phototherapy. In vivo, the nanocomposite suppressed deep-seated tumor growth with minimal adverse effects in mice bearing orthotopic A549 human lung tumors. Taken together, these results demonstrated that our BPNS-GNBP nanocomposite could function as a promising dual-modality phototherapeutic agent for enhanced cancer therapy in future cancer treatments. STATEMENT OF SIGNIFICANCE: In this study, we established a new nanocomposite by assembly of gold nanobipyramids (GNBPs) on black phosphorus nanosheets (BPNSs). Characterization of this nanocomposite showed that BPNS-GNBP enhanced 1O2 generation and hyperthermia. BPNS-GNBP exhibited good tumor inhibition efficacy in vivo and in vitro owing to simultaneous dual-modal phototherapy functions. Moreover, BPNS-GNBP suppressed deep-seated tumor growth in vivo and did not show adverse effects in mice bearing orthotopic A549 human lung tumors. Overall, these results showed that BPNS-GNBP may be used as a promising dual-modal phototherapeutic agent for enhanced cancer therapy in future clinical applications.
Subject(s)
Antineoplastic Agents/therapeutic use , Gold/chemistry , Lung Neoplasms/drug therapy , Nanocomposites/chemistry , Phosphorus/chemistry , Photosensitizing Agents/therapeutic use , Animals , Antineoplastic Agents/radiation effects , Antineoplastic Agents/toxicity , Cell Line, Tumor , Gold/radiation effects , Gold/toxicity , Humans , Mice , Nanocomposites/radiation effects , Nanocomposites/toxicity , Phosphorus/radiation effects , Phosphorus/toxicity , Photochemotherapy , Photosensitizing Agents/radiation effects , Photosensitizing Agents/toxicity , Photothermal Therapy , Singlet Oxygen/metabolism , Xenograft Model Antitumor AssaysABSTRACT
Deposition of amyloid-ß (Aß) aggregates in the brain is a main pathological hallmark of Alzheimer's disease (AD), so inhibition of Aß aggregation has been considered as a promising strategy for AD prevention and treatment. Black phosphorus (BP) is a 2D nanomaterial with high biocompatibility and unique biodegradability, but its potential application in biomedicine suffers from the rapid degradability and unfunctionability. To overcome the drawbacks and broaden its application, we have herein designed an Aß inhibitor (LK7)-coupled and polyethylene glycol (PEG)-stabilized BP-based nanosystem. The PEGylated-LK7-BP nanosheets (PEG-LK7@BP) not only exhibited a good stability but also demonstrated a significantly enhanced inhibitory potency on Aß42 fibrillogenesis in comparison with its counterparts. This elaborately designed PEG-LK7@BP stopped the conformational transition and suppressed the fibrillization of Aß42, so it could completely rescue cultured cells from the toxicity of Aß42 (by increasing the cell viability from 72 to 100%) at 100 µg/mL. It is considered that PEG-LK7@BP could bind Aß species by enhanced electrostatic and hydrophobic interactions and thus efficiently alleviated Aß-Aß interactions. Meanwhile, the coupled LK7 on the BP surface formed a high local concentration that enhanced the affinity between the nanosystem and Aß species. Finally, PEG could improve the stability and dispersibility of the nanoplatform to make it show an increased inhibitory effect on the amyloid formation. Hence, this work proved that PEG-LK7@BP is a promising nanosystem for the development of amyloid inhibitors fighting against AD.
Subject(s)
Amyloid beta-Peptides/drug effects , Nanostructures/chemistry , Peptide Fragments/drug effects , Peptides/pharmacology , Phosphorus/pharmacology , Polyethylene Glycols/pharmacology , Amyloid beta-Peptides/toxicity , Cell Line, Tumor , Cell Survival/drug effects , Humans , Nanostructures/toxicity , Peptide Fragments/toxicity , Peptides/chemistry , Peptides/toxicity , Phosphorus/chemistry , Phosphorus/toxicity , Polyethylene Glycols/chemistry , Polyethylene Glycols/toxicity , Protein Conformation/drug effects , Protein Multimerization/drug effectsABSTRACT
Recently, phosphorene, a novel two-dimensional nanomaterial with a puckered surface morphology, was shown to exhibit cytotoxicity, but its underlying molecular mechanisms remain unknown. Herein, using large scale molecular dynamics simulations, we show that phosphorene nanosheets can penetrate into and extract large amounts of phospholipids from the cell membranes due to the strong dispersion interaction between phosphorene and lipid molecules, which would reduce cell viability. The extracted phospholipid molecules are aligned along the wrinkle direction of the phosphorene nanosheet because of its unique puckered structure. Our results also reveal that small phosphorene nanosheets penetrate into the cell membrane in a specific direction which is determined by the size and surface topography of phosphorene and the thickness of the membrane. These findings might shed light on understanding phosphorene's cytotoxicity and would be helpful for the future potential biomedical applications of phosphorene, such as biosensors and antibacterial agents.
Subject(s)
Cell Membrane/drug effects , Nanostructures/toxicity , Phosphorus/toxicity , Biosensing Techniques , Cell Membrane/chemistry , Cell Survival/drug effects , Hydrophobic and Hydrophilic Interactions , Molecular Dynamics Simulation , Nanostructures/chemistry , Phospholipids/chemistry , Phosphorus/chemistry , Surface PropertiesABSTRACT
Nutrient limitation of primary producers is a fundamental principle in biogeochemical oceanography and has been used with great success in prescribing understanding to patterns of marine primary productivity. In recent years the paradigm of nutrient limitation has expanded from single nutrient limitation towards concepts of co-limitation by multiple resources. Interactive effects between multiple limiting resources are now thought commonplace in marine microbial communities. Here we investigate the response exhibited by phosphate-limited Thalassiosira oceanica to elevated concentrations of the phosphate analogs vanadate, arsenate and molybdate. Enrichments in external arsenate and vanadate to phosphate-limited cultures act to suppress growth rates entirely, an effect not seen in phosphate replete conditions. Retardation of growth rates is attributed to mistaken uptake through ion promiscuity as evidenced by observations of significant intracellular accumulation of both arsenic and vanadium under phosphate limited conditions. We describe this novel co-limitation scenario as dependent antagonistic co-limitation (DAC), and suggest that this phenomenon of non-deliberate intracellular accumulation could be used as both a proxy of phosphate stress in the modern ocean and a possible marker of phosphate depletion limiting the duration of oceanic anoxic events.
Subject(s)
Diatoms/physiology , Metals/toxicity , Phosphorus/toxicity , Water Pollutants, Chemical/toxicity , Arsenic/toxicity , Oceans and SeasABSTRACT
As a new kind of two-dimensional nanomaterial, black phosphorus (BP) nanosheets have attracted significant interests in diverse bioapplications due to their unique structure and physicochemical properties. Despite BP nanosheets' advantages in cancer diagnosis and therapy applications, their biosafety issues are still unclear. Herein, we report a systematic study on the In Vitro and In Vivo toxicity of BP nanosheets. In Vitro experiments showed that BP nanosheets decrease the viability of human bronchial epithelial cells in a time- and dose-dependent manner. The mechanism study showed that BP nanosheets interfere with mitochondrial membrane potential, leading to an increase in intracellular ROS. These responses further initiated the activation of the caspase-3 and ultimately dictated cells to undergo apoptosis. Then, the In Vivo experiments of BP nanosheets revealed that single injection of BP nanosheets does not cause toxicity to mice in a short period of time, whereas multiple injections of BP nanosheets exert adverse effects on liver and renal function of mice. Interestingly, the liver and renal function of the mice returned to normal after a recovery period. Our findings provide insights into the rational design of BP nanosheets and guide their applications in biomedical fields.
Subject(s)
Nanostructures , Phosphorus , Animals , Apoptosis , Mice , Nanostructures/toxicity , Phosphorus/toxicityABSTRACT
Studies in ecological stoichiometry highlight that grazer dynamics are affected by insufficient food nutrient content (low phosphorus (P)/carbon (C) ratio) as well as excess food nutrient content (high P:C). Contaminant stressors affect all levels of the biological hierarchy, from cells to organs to organisms to populations to entire ecosystems. Eco-toxicological modeling under the framework of ecological stoichiometry predicts the risk of bio-accumulation of a toxicant under stoichiometric constraints. In this paper, we developed and analyzed a Lotka-Volterra type predator- prey model which explicitly tracks the environmental toxicant as well as the toxicant in the populations under stoichiometric constraints. Analytic, numerical, slow-fast steady state and bifurcation theory are employed to predict the risk of toxicant bio-accumulation under varying food conditions. In some cases, our model predicts different population dynamics, including wide amplitude limit cycles where producer densities exhibit very low values and may be in danger of stochastic extinction.
Subject(s)
Carbon/toxicity , Food Chain , Phosphorus/toxicity , Predatory Behavior , Animals , Computer Simulation , Daphnia , Ecology , Ecotoxicology , Environmental Monitoring , Models, Theoretical , Population Dynamics , Stochastic ProcessesABSTRACT
A rapid, sensitive, and selective fluorometric assay is described for the determination of chromium(VI) in real waters and living cells. The method is making use of nitrogen, phosphorus, and sulfur tri-doped carbon dots (NPS-CDs) which have absorption/emission maxima at 360/505 nm/nm. Cr(VI) has an absorption maximum at 350 nm and causes an inner filter effect (IFE) on the blue fluorescence of the NPS-CDs. The NPS-CDs were hydrothermally synthesized using p-aminobenzenesulfonic acid and tetrakis(hydroxymethyl)phosphonium chloride as precursors. The NPS-CDs were characterized by transmission electron microscopy, X-ray diffraction, and several spectroscopic methods. They are biocompatible and negligibly cytotoxic when tested with HeLa cells and MCF-7 cells even after 48 h of incubation. The NPS-CDs were used as fluorescent probes for Cr(VI). The detection limit is 0.23 µM (three times standard deviation versus slope), and the linear response covers the 1 to 500 µM chromate concentration range. The NPS-CDs were applied to the determination of Cr(VI) in real waters and living cells (HeLa and MCF-7) and gave satisfying results. Graphical abstractSchematic representation of hydrothermal synthesis of nitrogen, phosphorus, and sulfur tri-doped carbon dots (NPS-CDs) for Cr(VI) detection via inner filter effect (IFE). NPS-CDs were applied to the determination of Cr(VI) in living cells (HeLa and MCF-7) with satisfying results.
Subject(s)
Chromium/analysis , Fluorescent Dyes/chemistry , Quantum Dots/chemistry , Water Pollutants, Chemical/analysis , Carbon/chemistry , Carbon/toxicity , Cell Line, Tumor , Drinking Water/analysis , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/toxicity , Humans , Lakes/analysis , Limit of Detection , Microscopy, Confocal/methods , Microscopy, Fluorescence/methods , Nitrogen/chemistry , Nitrogen/toxicity , Phosphorus/chemistry , Phosphorus/toxicity , Quantum Dots/toxicity , Rain/chemistry , Rivers/chemistry , Spectrometry, Fluorescence/methods , Sulfur/chemistry , Sulfur/toxicity , Wastewater/analysisABSTRACT
Vascular calcification is a common complication in patients with chronic kidney disease (CKD). It is an important predictor of cardiovascular disease and all-cause mortality. Previous studies have confirmed that bone marrow mesenchymal stem cell (BMSC) therapy can reduce vascular calcification, but the specific mechanism is still controversial. In this study, we aimed to investigate the mechanisms of BMSC-derived exosomes (EXO) in improving vascular calcification. BMSCs were cultured and EXO were isolated using the Total Exosome Isolation Reagent. Human aortic vascular smooth muscle cells (HA-VSMCs) were cultured into three groups: control group, high phosphorus group, and high phosphorus plus EXO group. Then, indicators related to smooth muscle cell calcification and microRNA profiles were analyzed. BMSC-derived exosomes inhibited high phosphorus-induced calcification in HA-VSMCs. Besides, EXO treatment reduced calcium content and decreased the alkaline phosphatase (AKP) activity in high phosphorus co-incubated HA-VSMCs. MicroRNA (miRNA) and mRNA expression profiles analyses revealed that 63 miRNAs were significantly upregulated and 1424 genes were significantly downregulated in HA-VSMCs after EXO treatment. Functional miRNA-gene regulatory network revealed that mTOR, MAPK, and Wnt signaling pathway were involved in vascular calcification. BMSC-derived exosomes alleviated high phosphorus-induced calcification in HA-VSMC through modifying miRNA profiles.