Metrological approach to quantitative analysis of clinical samples by LA-ICP-MS: A critical review of recent studies

Metal distributions in human hair strand cross-section: Advanced analysis using LA-ICP-MS in dentistry

Human hair is a biomarker that is crucial in investigating toxic metal exposures. Thirteen elements (Li, Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Ag, Ba, and Hg) commonly found in hair strands from dentistry environments were investigated using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Previous studies have employed partial ablation along hair strands to avoid contamination from mounting materials. The partial ablation can be problematic if element chemistry within the hair is not homogeneous. In this study, element variations along cross-sections of human hair strands were investigated. A number of elements showed internal variations with most elements enriched at the cuticle, emphasizing the importance of complete ablation for the characterization of human hair element chemistry. Complete and partial ablation LA-ICP-MS results were verified against solution nebulization SN-ICP-MS. Complete LA-ICP-MS showed a better agreement with SN-ICP-MS. Therefore, the developed LA-ICP-MS method can be applied to monitor the health of dental workers and students exposed to dental environments.

Investigation on selenium and mercury interactions and the distribution patterns in mice organs with LA-ICP-MS imaging

It is the first time to investigate local distribution patterns of mercury (Hg) in mice organs after Hg and Se exposure with detection of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Two batch of adult mice were employed to be exposed to inorganic mercury (iHg) and methylmercury (MeHg) with or without Se at the dose of 55 μmol kg^-1. Tissue sections of brain, kidney, liver, and spleen from one batch mice were prepared to get local imaging of Hg by LA-ICP-MS. Tissues from another batch mice were used to quantify Hg and Se in tissues with ICP-MS after acid digestion. The results indicated that, for mice exposed to iHg, Hg mainly distributed in kidney, a little in liver, and hardly in brain and spleen; for mice exposed to MeHg, lower amount of Hg was found in kidney, liver and spleen, and almost no Hg was found in brain. It was interesting that for Hg and Se co-administration groups, higher level of Hg was observed in kidney, liver, spleen and even in brain than single Hg administration groups. In addition, Se level in organ tissues increased obviously not only in Se exposure group but also in MeHg exposure group, while the phenomenon was not observed in iHg exposure group. HepG2 cells were employed to investigate Se and Hg interactions in single cell level, similar bioaccumulation behavior of Hg was found between cells and mice organs. Higher level of Hg was observed in cells cultured with Se and Hg medium than cells cultured with single Hg medium. The results are expected to provide new insight to investigate Hg and Se interactions in animal bodies and in-vitro cells.

Current applications and future perspectives on elemental analysis of non-invasive samples for human biomonitoring

Humans are continuously exposed to numerous environmental pollutants including potentially toxic elements. Essential elements play an important role in human health. Abnormal elemental levels in the body, in different forms that existed, have been reported to be correlated with different diseases and environmental exposure. Blood is the conventional biological sample used in human biomonitoring. However, blood samples can only reflect short-term exposure and require invasive sampling, which poses infection risk to individuals. In recent years, the number of research evaluating the effectiveness of non-invasive samples (hair, nails, urine, meconium, breast milk, placenta, cord blood, saliva and teeth) for human biomonitoring is increasing. These samples can be collected easily and provide extra information in addition to blood analysis. Yet, the correlation between the elemental concentration in non-invasive samples and in blood is not well established, which hinders the application of those samples in routine human biomonitoring. This review aims at providing a fundamental overview of analytical methods of non-invasive samples in human biomonitoring. The content covers the sample collection and pretreatment, sample preparation and instrumental analysis. The technical discussions are separated into solution analysis and solid analysis. In the last section, the authors highlight some of the perspectives on the future of elemental analysis in human biomonitoring.

Arsenic and arsenic speciation in mushrooms from China: A review

Arsenic (As) is a natural environmental contaminant to which humans are usually exposed in water, air, soil, and food. China is a typical high-As region, and also a great contributor of the world production of cultivated edible mushrooms and a region abundant in wild growing edible mushrooms. Mushrooms can accumulate different amounts of As and different As compounds, so potential health risk of As intake may exist to people who use mushrooms with elevated As contents as food or medicine. A systematic literature search was carried out for studies on As and As compounds in mushrooms from China. We compiled existing data from published sources in English or Chinese and provide an updated review of the findings on As in mushrooms associated with environments and health risks. Future perspectives for studies on As in mushrooms have also been discussed.

Effect of Gold Nanoparticle on 5-Fluorouracil-Induced Experimental Oral Mucositis in Hamsters

BACKGROUND

Oral mucositis (OM) is a severe inflammation of the oral mucosal cells associated with chemotherapy and/or radiotherapy-induced toxicity, resulting in epithelial ulcers and higher risk of death from sepsis. The aim of the present study was to evaluate the nanoparticle (AuNp) effect on OM induced in hamsters.

MATERIALS AND METHODS

5-fluorouracil (5FU) was used on the first and second day of the experimental model in Golden sirian hamsters, and on the fourth day, mechanical trauma was applied to induce OM. The animals were divided into groups, i.e., polyvinylpyrrolidone (PVP), mechanical trauma (MT), 5FU, and groups treated with gold nanoparticles (AuNps) (62.5, 125, and 250 μg/kg). On the 10th day, animals were euthanized for macroscopic, histopathological, immunohistochemical, western blot, quantitative polymerase chain reaction (qRT-PCR), and AuNp quantification.

RESULTS

AuNp (250 μg/kg) reduced TNF-α, IL-1β, COX-2, NF-κB, TGF-β, and SMAD 2/3; increased glutathione levels; decreased the expression of Kelch ECH-associated protein 1 (KEAP1); and induced heme oxygenase 1 (HMOX-1) and NAD (P) H quinone oxidoreductase 1 (NQO1) genes.

CONCLUSIONS

AuNp (250 μg/kg) prevented 5-FU-induced OM in hamsters and improved the parameters of inflammation and oxidative stress.

Laser ablation ICP-MS for simultaneous quantitative imaging of iron and ferroportin in hippocampus of human brain tissues with Alzheimer's disease

Laser ablation inductively coupled plasma - mass spectrometry (LA-ICP-MS) is proposed for a better understanding of metals and proteins distribution in micrometre structures of human brain tissues. Simultaneous absolute quantitative imaging of Fe and ferroportin (FPN), in 5 µm thick tissue sections of the stratum pyramidale of hippocampus CA1 region, was carried out for Alzheimer disease (AD) patients and healthy controls (HC). For the imaging of FPN by LA-ICP-MS, antibodies were labelled via carbodiimide crosslinking with fluorescent gold nanoclusters (AuNCs) of 2.2 nm diameter, enabling a high amplification (314 gold atoms per NC). Laboratory made gelatin standards containing Fe and Au were used for LA-ICP-MS calibration. Results showed that iron presents an increased concentration in AD donors compared with HC donors, whereas similar concentrations of FPN in AD donors with respect to HC donors were obtained. The average absolute FPN concentrations in selected areas obtained with the proposed AuNCs method were compared with the levels obtained by densitometric analysis with a traditional IHC approach, observing a similar trend in all cases.