Inductively Coupled Plasma Mass Spectrophotometry Research Articles

The first full study of heavy metal(loid)s in western-European hedgehogs (Erinaceus europaeus) from Portugal

The western-European hedgehog (Erinaceus europaeus) is an insectivore with a wide distribution in Portugal and a potential tool for biomonitoring relevant One Health hazards, including heavy metal(loid)s’ pollution. The aim of this study was to positively contribute to the current knowledge about the metal(loid) pollution in Portugal. Forty-six hedgehogs (from rescue centres; with known provenance) were necropsied. Sex, age category and weight were determined. Spines, liver and kidney were collected, and metalloid concentrations were determined by inductively coupled plasma mass spectrophotometry (ICP-MS). In general, results did not present alarming metal(loid) concentrations, with the exception of cadmium (Cd) (in the kidneys) and copper (Cu). Hedgehogs from Viana do Castelo and Viseu showed elevated concentrations of arsenic (As) and Castelo Branco presented concerning values of cadmium (Cd). Adult and heavier hedgehogs tended to present higher levels of metal(loid)s. Sex does not seem to significantly affect the metal(loid)s’ concentrations. Further analysis would be needed to prioritize areas with detail and allow the application of the necessary mitigation strategies.

Heavy metals and metalloids in wild boars (Sus Scrofa) - a silent but serious public health hazard.

Wild boars (Sus scrofa) are part of the hunting economy and are highly consumed in the Iberian Peninsula, including in the Castile and Leon regions. As zoonotic diseases, chemical pollutants in wild boars' internal tissues should be interpreted as evidence of environmental contamination and a matter of concern for animal, human and ecosystem health; in other words, a One Health concern. Twenty-eight wild boars' livers and kidneys (n = 28) from Castile and Leon were submitted to metal(loid) determination (As, Cd, Co, Cr, Cu, Ni, Pb, and Zn) with inductively coupled plasma mass spectrophotometry (ICP-MS) and histopathological exam. Cd levels, especially in the kidneys (7.063 ± 7.271mg/kg dw), were the most concerning results, considering the calculated maximum values for consumption (EC No. 915/2023) (2.491mg/kg dw or 1.0mg/kg ww). Wild boars with hydropic changes in the liver presented higher concentrations of Ni. Thus, the metal(loid) contamination of wild boar carcasses seems to be a "no trace" but very relevant problem that should raise awareness of a more accurate monitoring program and other strategies to avoid public health consequences.

Assessment of heavy metal concentrations in Scophthalmus maximus (Linnaeus, 1758) from the Black Sea coast: Implications for food safety and human health

The present study aimed to investigate the concentrations of heavy metals (Cd, Hg, Pb, Cu, Zn, Fe) in turbot (Scophthalmus maximus) samples collected from the Black Sea coast in 2022. The research involved analysing male and female turbot samples for their potential to accumulate these metals and assessing the associated health risks for different age groups (infants, children, adults). Metal analyses were conducted using Inductively Coupled Plasma Mass Spectrophotometry (ICP-MS), and risk assessment was performed using the Hazard Quotient (THQ) and Risk Index (RI) methods.Results showed that the mean concentrations of heavy metals in both male and female turbots were consistently below the established safety limits set by national and international regulatory authorities. The Estimated Daily Intake (EDI) and THQ values for all metals were found to be well below the corresponding reference doses, indicating no significant noncarcinogenic health risks associated with turbot consumption. Furthermore, the RI values for metals with available Cancer Slope Factors (CSF) were extremely low, suggesting negligible carcinogenic risk from consuming turbot.

Cadmium alters whole animal ionome and promotes the re-distribution of iron in intestinal cells of Caenorhabditis elegans.

The chronic exposure of humans to the toxic metal cadmium (Cd), either occupational or from food and air, causes various diseases, including neurodegenerative conditions, dysfunction of vital organs, and cancer. While the toxicology of Cd and its effect on the homeostasis of biologically relevant elements is increasingly recognized, the spatial distribution of Cd and other elements in Cd toxicity-caused diseases is still poorly understood. Here, we use Caenorhabditis elegans as a non-mammalian multicellular model system to determine the distribution of Cd at the tissue and cellular resolution and its effect on the internal levels and the distribution of biologically relevant elements. Using inductively coupled plasma-mass spectrophotometry (ICP-MS), we show that exposure of worms to Cd not only led to its internal accumulation but also significantly altered the C. elegans ionome. Specifically, Cd treatment was associated with increased levels of toxic elements such as arsenic (As) and rubidium (Rb) and a decreased accumulation of essential elements such as zinc (Zn), copper (Cu), manganese (Mn), calcium (Ca), cobalt (Co) and, depending on the Cd-concentration used in the assay, iron (Fe). We regarded these changes as an ionomic signature of Cd toxicity in C. elegans. We also show that supplementing nematode growth medium with Zn but not Cu, rescues Cd toxicity and that mutant worms lacking Zn transporters CDF-1 or SUR-7, or both are more sensitive to Cd toxicity. Finally, using synchrotron X-Ray fluorescence Microscopy (XRF), we showed that Cd significantly alters the spatial distribution of mineral elements. The effect of Cd on the distribution of Fe was particularly striking: while Fe was evenly distributed in intestinal cells of worms grown without Cd, in the presence of Cd, Fe, and Cd co-localized in punctum-like structures in the intestinal cells. Together, this study advances our understanding of the effect of Cd on the accumulation and distribution of biologically relevant elements. Considering that C. elegans possesses the principal tissues and cell types as humans, our data may have important implications for future therapeutic developments aiming to alleviate Cd-related pathologies in humans.

Assessment of Heavy Metal Concentrations in Water Purifier Devices in Rafsanjan City

Introduction: Heavy metals (HMs) are one of the most important and dangerous pollutants in water resources. This study aimed to determine the HMs concentrations in city water purifier devices or stations in Rafsanjan, Iran in 2022.
 Materials and Methods: This study was conducted descriptively and on a laboratory scale on the input and output of 16 city water purifier devices stations in Rafsanjan in the summer of 2022. Heavy metals and other metals including arsenic (As), lead (Pb), chromium (Cr), copper (Cu), zinc (Zn), iron (Fe), magnesium (Mg), calcium (Ca), sodium (Na), and potassium (K) were tested by inductively coupled plasma mass spectrophotometry (ICP-MS). Also, t-test statistical analysis was used by SPSS software.
 Results: The mean concentrations of HMs in the output of city water purifier devices for As, Pb, Cr, Cu, and Zn were ≤ 1, 2.84 ± 0.71, 8.48 ± 1.51, 2.51 ± 1.55, and 18.58 ± 9.24 µg/L, respectively. The difference between the output of water purifier devices and standard values ​​for As, Cr, and Cu was significant (p ≤ 0.001). Other metals concentrations in the output of water purifier devices for Fe, Mg, Ca, Na, and K were 0.03 ± 0.008, 6.72 ± 0.92, 8.38 ± 1.71, 64.11 ± 2.56, and 2.34 ± 0.08 µg/L, respectively. The HMs removal efficiency of city water purifier devices for As, Cu, and Pb were ≥ 99%, 83.33%, and 56.33%, respectively.
 Conclusion: The HMs removal efficiency of city water purifier devices stations in Rafsanjan City was appropriate due to the use of filters containing alumina and iron hydroxide media.

Hubungan Jenis Pestisida Berdasarkan Kandungan Senyawa Aktif yang Digunakan terhadap Kadar Timbal (Pb) dalam Darah Petani di Kabupaten Bangka

Farmers exposed to pesticides. It can cause pollution and residues. Pesticides contain Plumbum (Pb). Pb can effect to the hematopoietic, digestive, urinary, kidney, central nervous, reproductive, cardiac and endocrine systems. The purpose was to determine the relationship between types of pesticides based on the active compounds used on Pb levels in the farmers blood in Bangka district. This research is analytic observational with cross sectional approach. The subjects were 20 farmers exposed to pesticides and with criteria based on the questionnaire in Bangka district. Use quota sampling. Primary data, namely measurement of blood lead levels using the Inductively Coupled Plasma - Mass Spectrophotometry (ICP-MS) method and types of pesticides based on active compounds. Level of Pb in the farmer's blood was the highest level of 6.6 g/dL and the lowest level of 1.7 g/dL with an average of 4.1 g/dL and still within normal limits. Respondents who used organophosphate pesticides found the highest levels of 6.6 g/dL and the lowest levels of 2.5 g/dL with an average of 4.36 g/dL. Respondents who used carbamate pesticide obtained the highest level of 5.1 g/dL and the lowest level of 1.7 g/dL with an average of 4.06 g/dL. The results from the ANOVA test with an F count of 4.789 and a significance level of probability 0.032 < 0.05, there was a significant relationship between types of pesticides based on the content of active compounds used by farmers on blood lead levels in Bangka district.

KCMF1 regulates autophagy and ion channels' function in renal cell carcinoma: a future therapeutic target.

In RCC, systematic procedures such as surgery, chemo-radiation therapy, and application of target-based inhibitors increase the risk of several comorbidities such as chronic kidney disease, hemorrhage, and cardiac arrest that may increase the mortality rate. Even though immune-based checkpoint inhibitor therapies have an overall good response rate, it is restricted to only 30-40% of patients. Hence, an in-depth study of tumor pathophysiology in RCC is needed to identify the new therapeutic target. In RCC, persisted hypoxia is an essential phenomenon for tumor growth and progression. KCMF1 is a newly identified ubiquitin ligase whose domain interacts with destabilized proteins and reprogrammed the ubiquitin coding for lysosome-mediated degradation and autophagy under hypoxic conditions/oxidative stress and maintaining cellular homeostasis. But in RCC, the functional role of KCMF1 remains undefined to date. We determined KCMF1 and its associated proteins RAD6 and UBR4 expression and their co-localization using confocal microscopy in tumor and non-tumor tissues samples.Further,immunofluorescencestaining wasperformed to determineautophagy(LC3B, p62), hypoxia-induciblefactor (HIF-1A) and ion channel markers(Kv1.3, KCNN4) in RCC patients(n-10).Inductively coupled plasma mass spectrophotometry (ICPMS) was performedto estimate theconcentration of potassium (K+), sodium (Na+) and Zinc (zn2+) in tumor and non-tumor cells of RCC patients (n-20). Lastly, images were analyzed usingZEN3.1, and ImageJsoftware. We observed a discrepancy in the formation of ubiquitin ligase, autophagosome via KCMF1, and ionic concentration in tumor cells, which might be one of the possible factors for cancer evolution. KCMF1-associated ubiquitin ligase system could be considered as a novel therapeutic target for RCC in the future.

Assessment of DNA damage in relation to heavy metal induced oxidative stress in females with recurrent pregnancy loss (RPL).

Pregnancy termination consecutively for three or more times during the first trimester is termed as Recurrent pregnancy loss (RPL). In addition to the abnormal karyotype, heavy metal induced oxidative damage may contribute as prominent etiological factor in pregnancy termination. Oxidative stress is considered crucial in etiology underlying RPL with altered antioxidant status and subsequent DNA damage. The current case controlled study investigated Total antioxidant capacity (TAC), DNA damage (8OHdG) and heavy metals in RPL group (n = 30) and the women with successful pregnancies and no cases of miscarriage as control group (30 women). Heavy metals -Antimony (Sb) and Arsenic (As) were measured by Inductively Coupled Plasma Mass spectrophotometry (ICP-MS). There was significant decrease in levels of TAC in RPL group compared to healthy pregnant women (P < 0.05). On contrary, elevated levels of As and Sb were observed in RPL group with subsequent increase in the levels of 8OHdG (P < 0.001); indicating extensive DNA damage in these patients. Furthermore, increased levels of As and Sb in RPL group were positively correlated with 8OHdG and negatively with total antioxidant capacity. The outcome of the study provides clear insight of the role of metal induced oxidative stress that plays a vital role in the pathophysiology underlying RPL.

HEAVY METAL CHARACTERISTICS OF WASTEWATER FROM BATIK INDUSTRY IN YOGYAKARTA AREA, INDONESIA

Batik is Indonesian traditional textile product. The increasing use of synthetic dyes in batik production raises concern on heavy metal content in its wastewater. As wastewater from most factories is released to the environment without proper treatment, the pollutants including heavy metal content would pose health risks to humans and the environment. However, data on heavy metal characteristics of wastewater from batik industry in Indonesia is very limited. This paper presents the profile of heavy metal characteristic of 17 (seventeen) wastewater samples from batik factories in Yogyakarta Area, Indonesia. The total concentration of some heavy metals elements were measured by using inductively-coupled plasma mass spectrophotometry (ICP-MS). The result was compared to other studies and relevant local and international effluent standards.Hierarchical Cluster Analysis (HCA) was then performed to observe group of samples or parameters with similar characteristics that represent similar production method which affects their wastewater characteristics.The results showed that concentration of Cr, Co, Ni, Cu, As, Cd, and Pb ranged from 9.87 to 101 ppb, 0.03 to 3.89 ppb, 5.37 to 82.8 ppb, 19.7 to 472 ppb, 1.46 to 21.2 ppb, 0.03 to 20.3 ppb and 0.78 to 40.1 ppb respectively.In general, concentration of heavy metal in this study does not exceed regulation and also lower than result of other studies. HCA result confirmed that the source of Ni, Cr and Cu is from dye. HCA also indicated that other factors may affect the heavy metal concentration in batik wastewater which demands further study.

Excessive intake of iodine and low prevalence of goiter in school age children five years after implementation of national salt iodization in Shebedino woreda, southern Ethiopia

BackgroundIodine is a trace element required for the synthesis of thyroid hormones. The multiple effects of iodine deficiency on human health are called iodine deficiency disorders (IDDs). IDDs have been common nutritional problems in Ethiopia. In 2012, Ethiopia launched a national salt iodization program to address IDDs. The objective of this study was to assess the effects of this program after 5 years by measuring urinary iodine concentration (UIC) and prevalence of goiter in school age children as well as household salt iodine concentration (SIC).MethodsA school-based cross-sectional design was employed. After ethical approval, 408 children from eight randomly selected primary schools provided urine samples. UIC was analyzed by inductively coupled plasma mass spectrophotometry (ICP-MS). A 10 g salt sample was collected from each household of a sampled child. SIC was analyzed with a digital electronic iodine checker (WYD, UNICEF) and goiter was assessed by palpation.ResultsThe mean (±SD) age of the children was 9 ± 2 years. The prevalence of goiter was 4.2% and no child had grade 2 goiter. The median (IQR) UIC was 518 (327, 704) μg/L and UIC ranged from 3.1 to 2530 μg/L. Of the salt samples, 15.6% were not adequately iodized (< 15 ppm), 39.3% were adequately iodized (≥15 to ≤40 ppm), and 45.1% were > 40 ppm. SIC ranged from 4.2 to 195 ppm. Of the mothers, 92% said iodized salt prevents goiter and 8% mentioned prevents mental retardation.ConclusionsIn 2017 iodine deficiency was no longer a public health problem in the study area. However, the high variability in UIC and SIC and excessive iodine intake are of great concern. It is vital to ensure that salt is homogenously iodized at the production site before being distributed to consumers.

Uptake, translocation, and physiological effects of hematite (α-Fe2O3) nanoparticles in barley (Hordeum vulgare L.)

There has been a growing concern with the environmental influences of nanomaterials due to recent developments in nanotechnology. This study investigates the impact and fate of hematite nanoparticles (α-Fe2O3 NPs) (∼14 nm in size) on a crop species, barley (Hordeum vulgare L.). For this purpose, hematite NPs (50, 100, 200, and 400 mg/L) were hydroponically applied to barley at germination and seedling stages (three weeks). Inductively coupled plasma mass spectrophotometry (ICP-MS) along with vibrating sample magnetometer (VSM) techniques were used to track the NPs in plant tissues. The effects of NPs on the root cells were observed by scanning electron microscopy (SEM) and confocal microscopy. Results revealed that α-Fe2O3 NPs significantly reduced the germination rate (from 80% in control to 30% in 400 mg/L), as well as chlorophyll (36–39%) and carotenoid (37%) contents. Moreover, the treatment led to a significant decline in the quantum yield of photosystem II (Fv/Fm). Leaf VSM analysis indicated a change in magnetic signal for NPs-treated samples compared with untreated ones, which is mostly attributed to the iron (Fe) ions incorporated within the leaf tissue. Besides, Fe content in the roots and leaf had gradually increased by the increasing doses of NPs, which was confirming NPs’ translocation to the aerial parts. Microscopic observations revealed that α-Fe2O3 NPs altered root cell morphology and led to the injury of cell membranes. This study, in the light of our findings, shows that α-Fe2O3 NPs (∼14 nm in size) are taken up by the roots of the barley plants, and migrate to the plant leaves. Besides, NPs are phytotoxic for barley as they inhibit germination and pigment biosynthesis. This inhibition is probably due to the injury of the cell membranes in the roots. Therefore, the use of hematite NPs in agriculture and thereby their environmental diffusion must be addressed carefully.

Relationships between microvascular complications of diabetes mellitus and levels of macro and trace elements.

The aim of this study was to determine relationships between microvascular complications of type 2 diabetes mellitus (T2DM) and trace element levels measured by ICP-MS. One hundred eighteen patients with T2DM (age: 30-65 years) and 40 control subjects were included in the study. The T2DM patients were divided into three groups according to their types of microvascular complications. Patients in group 1 (N.=40) had no microvascular complications. Group 2 included 38 patients with only diabetic retinopathy. Group 3 included 40 patients with diabetic retinopathy and nephropathy. Trace elements, including chromium (Cr), copper (Cu), and zinc (Zn), were measured by inductively coupled plasma mass spectrophotometry (ICP-MS). Mg levels analyzed by ICP-MS were lower in patients with T2DM than in healthy subjects. Additionally, Mg level of 2.1 mg/dL or less was found to be predictive for risk of occurrence of T2DM with no microvascular complications. Cr levels were significantly lower in T2DM patients with diabetic retinopathy and diabetic nephropathy than in T2DM patients with no microvascular complications. Additionally, levels of Cr were much lower significantly in group 3 than in group 2. The predictive value of Cr levels (area under the curve [AUC]=0.734, P=0.007) for occurrence of diabetic retinopathy was 15.2 μg/L (sensitivity = 70%; specificity = 60.5%). This study showed an association between especially low Mg and Cr levels measured via ICP-MS and microvascular complications in patients with T2DM.

Effect of thermocycling on the surface texture and release of titanium particles from titanium alloy (Ti6Al4V) plates and dental implants: An in vitro study

Statement of problemThe release of titanium (Ti) particles from the surface of endosseous dental implants is not well understood. PurposeThe purpose of this in vitro study was to evaluate the effect of thermocycling on the surface texture and release of Ti particles from the surface of dental implants. Material and methodsThree MSI dental implants and 3 Ti alloy (Ti6Al4V) plates were divided into 6 subgroups (n=3). Specimens in each group were subjected to 0 (control group), 100, 200, 500, 1000, and 2000 thermocycles. After each cycling process, artificial saliva was collected, and the concentrations of released Ti particles were quantified by inductively coupled plasma-mass spectrophotometry (ICP-MS). The surfaces of the dental implants and Ti plates were evaluated before and after thermocycling by scanning electron microscopy (SEM), and SEM images were analyzed by using the ImageJ software program. Data were analyzed by mixed-model ANOVA and post hoc Tukey tests (α=.05). ResultsThe greatest Ti release was seen after 2000 thermocycles. After increasing the number of cycles, additional Ti particles were released. SEM images of the surfaces of the dental implants and Ti plates displayed significant changes in surface texture. ConclusionsThermocycling continuously removed the protective TiO2 layer on the surface of dental implants, resulting in the release of Ti particles. The surface treatment and texture did not affect the release of Ti particles.

Assessment of Heavy Metal Contents of Mulberry Samples (Fruit, Leaf, Soil) Grown in Gumushane Province

The present study aims to identify the heavy metal contents of white mulberry (Morus alba L.) and black mulberry (Morus nigra L.) that are grown in the city center of Gumushane province and its neighboring counties. Heavy metal analyzes were performed in the fruits, leaves and soils of the plants. The control samples, on the other hand, were collected from the mulberry trees located 3 km away from the highway where the vehicle traffic and industrial activities are at their lowest. Sample collection was performed twice a year, namely during the ripening period and fully ripening period of the fruits. The analyses of the heavy metals were performed by using inductively coupled plasma-mass spectrophotometry (ICP-MS). The obtained results were compared with the acceptable limits of heavy metal for humans as established by the World Health Organization (WHO), Turkish Food Codex (TFC) and the literature and an opinion was submitted as to whether they present any risk in terms of human health. When the available data is evaluated, the mulberries grown in Gumushane province, were found to have presented a health risk in terms of Pb, Cd, Ni, Cu, Zn, Mn and Co metals.

Comparative investigations of the effects of Kanwa (Trona) and Tokansenyi (plant potash) on liver and kidney of albino rats

Kanwa (Trona) and Tokansenyi (Plant potash) are food tenderizers that are commonly used in developing countries especially. Their advantage in improving texture of food and in health cannot be over emphasized.However, long-term consumption of these salts has some health implications. Therefore this study is to compare the effects of these two salts onalbino rats so as to determine which one is safer. Albino rats were grouped into three groups, with the first group as control, second group contains water with three grams of Tokansenyi and the third group contains water with three grams of Kanwa. Blood samples for liver and kidney function test were collected after six weeks. Organs (liver and kidney) were also collected for histological studies. The salts element composition were analysed using Inductively Coupled Plasma – Mass Spectrophotometry (ICP-MS). At end of the period of treatments no mortality was recorded and no any visible sign of toxicity. The results obtained for liver and kidney enzymes concentration AST, ALT and ALP; for both treatments shows significant difference (P &lt; 0.05) as compared with the control.The total bilirubin concentration for blood of albino rats treated with Kanwa shows significant difference (P &lt; 0.05). The concentration of urea in both treatments also shows significant difference (P &lt; 0.05) as compared with control. The histological results for liver treated with kanwa revealed a sinusoid with bodies stained with deep red colouration, enlarged nuclei and distorted cord-like arrangement of hepatocytes. The histological results for kidney treated with Kanwaalso revealed a degenerated collecting duct and inflammated glomeruloid. The elemental composition of both salts showed similar concentration for most of the elements including the toxic ones. However, some elements like Mo, Mn and Co showed higher concentration in Tokansenyi as compared to Kanwa. The study revealed that Tokansenyi is safer for the liver and kidney as compared with Kanwa (Trona). The study has shown that Tokansenyi and relatively safer than Kanwa.Keywords: Kanwa (Trona), Tokansenyi (Plant Potash), albino rats, liver, kidney.

Hair Zinc: an Index for Zinc Status in Under-Five Children from Low-Income Communities in Kanam Area of North-Central Nigeria.

Nutritional deficiencies of trace elements are among the top ten causes of death in Sub Saharan Africa. In Kanam Local Government Area of Nigeria, the problem is compounded by high levels of poverty and illiteracy. Abnormally low hair zinc levels are important, sensitive diagnostic biochemical indices of Zinc deficiency. The purpose of this study is to assess the zinc status of children less than 5years in Kanam local government area, north-central Nigeria, by measuring the zinc level in hair samples collected from 44 under-5 children across the area. A household survey was made to assess the pattern and frequency of consumption of zinc-rich foods which was done by means of questionnaire. Hair samples were analysed for zinc content by the inductively coupled plasma-mass spectrophotometry (ICP-MS). The data were analysed statistically using the Student's t test, z test, and Pearson correlation, while questionnaire-captured data were analysed by simple arithmetic. The results of the analyses showed that the average hair zinc level was 74.35±48.05μg/g. This was below the normal range of 130-140μg/g, for children less than 5years. Based on the results, 86.36% have hair zinc level below the lower limit of the normal range of 130μg/g. Between the gender, boys have higher hair zinc content than girls. Data from the questionnaire showed that 53.45% of the population studied have poor/inadequate intake of zinc-rich foods of animal origin, a dietary behaviour reported to predispose to micronutrient deficiency, including zinc.

In Vivo Micro-CT Imaging of Human Mesenchymal Stem Cells Labeled with Gold-Poly-L-Lysine Nanocomplexes.

Developing in vivo cell tracking is an important prerequisite for further development of cell-based therapy. So far, few computed tomography (CT) cell tracking studies have been described due to its notoriously low sensitivity and lack of efficient labeling protocols. We present a simple method to render human mesenchymal stem cells (hMSCs) sufficiently radiopaque by complexing 40 nm citrate-stabilized gold nanoparticles (AuNPs) with poly-L-lysine (PLL) and rhodamine B isothiocyanate (RITC). AuNP-PLL-RITC labeling did not affect cellular viability, proliferation, or downstream cell differentiation into adipocytes and osteocytes. Labeled hMSCs could be clearly visualized in vitro and in vivo with a micro-CT scanner, with a detection limit of approximately 2×104 cells/μl in vivo. Calculated HU values were 2.27 /pg of intracellular Au as measured with inductively coupled plasma mass spectrophotometry (ICP-MS), and were linear over a wide range of cell concentrations. This linear CT attenuation was observed for both naked AuNPs and those that were taken up by hMSCs, indicating that the number of labeled cells can be quantified similar to the use of radioactive or fluorine tracers. This approach for CT cell tracking may find applications in CT image-guided interventions and fluoroscopic procedures commonly used for the injection of cellular therapeutics.

Speciation of dissolved chromium and the mechanisms controlling its concentration in natural water

The circulation of chromium at naturally occurring concentration levels (i.e., 1μgdm−3 or lower) was examined using solid-phase spectrophotometry and inductively coupled plasma-mass spectrophotometry (ICP-MS) to determine the Cr(VI) and Cr(Total) concentrations, respectively. Natural water and stream sediments were collected from areas with various types of geologic features, such as metamorphic rocks, volcanic rocks and limestone in Japan and Indonesia. Cr(VI) was predominant in weakly alkaline natural waters, and the Cr(III) concentration was less than 1μgdm−3, which was considerably lower than that expected based on the solubility of Cr(OH)3. The dissolution of chromium in natural water was described by the leaching of Cr(VI) from Cr(III)-containing minerals under oxic conditions. The Cr(VI) concentration in a solution that was in contact with chromite, FeCr2O4, linearly increased with the reaction time. The results indicated that under oxic conditions at PO2=0.21atm, the leaching rate of Cr(VI) was pseudo zero-order at a fixed pH and was higher in alkaline than in acidic solutions. The removal of Cr from natural waters was due to the reduction of Cr(VI) to Cr(III) by organic matter, such as humic substances, as well as to the adsorption of Cr(III) onto suspended matter and river sediments. The reduction of Cr(VI) to Cr(III) followed the equation −d[Cr(VI)]/dt=[H+]a[Cr(VI)][DOC] with a=0 at pH<4 and a=−1 at pH>4.5. The removal of Cr(III) by river sediments and/or suspended particulate matter was rapid and the adsorbability of Cr(III) was dependent on pH, which suggests that the active species were Cr(OH)2+ and Cr(OH)3. Schematic models of the circulation of dissolved chromium in natural water were proposed under acidic and alkaline conditions.

Intracellular uptake of magnetite nanoparticles conjugated with RGDS-peptide

Peptides containing the Arg-Gly-Asp (RGD) motif inhibit cell adhesion and exhibit a range of other biological effects including anticoagulant and antimetastatic activities. This study examined the anchorage independent effects of an RGD-containing peptide, Arg-Gly-Asp-Ser (RGDS), on NIH 3T3 fibroblasts. Magnetite nanoparticles were prepared by the coprecipitation of ferrous iron (Fe2+) and ferric iron (Fe3+) with NH4OH and dextran (DNPs). The aminosilane agent of 3-aminopropyltriethoxysilane (A) is considered to be a candidate for modification of the surface of magnetite nanoparticles (ADNPs). The amino-functionalized magnetite nanoparticles were activated using the glutaraldehyde (G) method (GADNPs). Subsequently, RGD or RGDS peptides were immobilized on the glutaraldehyde-modified magnetite nanoparticles (RGADNPs or RSGADNPs). The RSGADNPs were evaluated using Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS). The biological responses of the RSGADNPs were evaluated using NIH 3T3 fibroblast cells. Inductively coupled plasma mass spectrophotometry (ICP-MS) and Prussian blue staining showed that the RSGADNPs were internalized into the NIH 3T3 cells compared to the RGADNPs. These results suggest that RSGADNP may find ever-growing applications in biological labels and detection or contrast agents in life science and medical diagnostics.

Photochromic crowned spirobenzopyrans: Quantitative metal-ion chelation by UV, competitive selective ion-extraction and metal-ion transportation demonstration studies

Following our publication of the synthesis of the new 5-substituted crowned spirocyclic benzopyrans ( 3a– c), and the fact that suitably placed substituents can be used to influence their metal-ion chelating properties [Roxburgh, CJ, Sammes, PG. Dyes Pigments 1995;28:317.], we now report the results of an extensive quantitative study to demonstrate that these systems selectively and photoreversibly chelate a variety of metal-ions i.e. Li +, Na +, Ca 2+, Ba 2+, and Mg 2+. Experiments were conducted at seven different spiropyran concentrations, for each of the three crowned spiropyrans, and with the five different metal-ions (above). The 5-trifluoromethyl-substituted system produced the most pronounced effects and was thus chosen as the best system for further selective investigations which include: (1) competitive relative selective metal-ion chelating capability – investigated by devising a ‘matrix’ series of experiments, in order to ascertain which metal-ions, under dual competition (two metal-ions simultaneously present) were relatively more chelated (a priority order for the relative selectivity was consequently deduced), and (2) a system and experiments were devised to demonstrate that metal-ions could reversibly, under photodynamic control, be transported across a barrier (an immiscible layer of 1,2-dichloroethane and water: metal-ion concentrations were measured before and after photoirradiations using inductively coupled plasma mass spectrophotometry (ICP-MS) a powerful and accurate analytical technique for the quantification of metal-ions) to establish the levels of transportation.