Food Science and Human Wellness, 11(6), 1482-1490, 2022

The present study aimed at making a rational usage for European eel bone by-products by preparing Europen eel bone peptide chelated calcium (EBPC-Ca). Nutritional properties and bioactivity of EBPC-Ca were evaluated. Results showed that nutritional properties of calcium ions will cause intra- and inter-molecular folding and aggregation of peptide to uniformly form EBPC-Ca chelate. The chelated compound of EBPC and calcium ion triggered a strong apoptosis in heterogeneous human epithelial colorectal adenocarcinoma (Caco-2) in concentration- and time-dependent manners. Western blot analysis revealed that the EBPC-Ca induced apoptosis may be the result of a blocked autophagy flux through mitochondrial-dependent pathway. Additionally, the increase in FGF-23 protein expression inhibited the absorption of calcium ions and alleviated cell apoptosis. It was also found that the cell apoptosis occurs with significant increases in the levels of reactive oxygen species (ROS) and Ca2+ in the cells, indicating the anti-tumor potential of EBPC-Ca may involve multiple channels.

TOF-SIMS and FE-SEM/EDS to verify the heavy metal fractionation in serpentinite quarry soils

CATENA, 136, 2016, 30–43

http://dx.doi.org/10.1016/j.catena.2015.03.005

This study aims at extensively defining serpentinite quarry soils and analysing their content and distribution of heavy metals using chemical sequential extraction. The association with the different geochemical phases of the soil was verified using TOF-SIMS and SEM-EDS techniques. Seven soils were chosen in two serpentinite quarries located in Moeche (M) and Silleda (C) (Galicia, northwest of Spain). The selected areas for soil sampling were: dump sites (M1, M2 and C1), rock extraction sites (M3, C2), and quarry boundaries (M4 and C3). The total soil concentration of Co, Cr, Ni, and V varied from 1472 to 7132, 1499 to 4309, 76 to 373, and 21 to 140 mg kg− 1, respectively. In all cases they exceed the maximum limit permitted in soils. After chemical sequential extraction it was found that the high content of Co, Cr, Ni, and V is associated with the residual fraction of the soils. In addition, Fe and Mn oxides have a high capacity for Co fixation, whereas Cr, Ni, and V are mainly associated with magnesium silicates. The fractions related to organic matter and the soluble or available forms are, respectively low and very low, not exceeding 2.5% in any of the soils. This association of the metals with magnesium silicates and Fe oxides, and the low content of metals bound to organic matter were identified by using the TOF-SIMS and SEM-EDS techniques. Both techniques confirmed and verified the results obtained during the chemical sequential extraction by checking the interaction of heavy metals with the different components of the soil.

Using calcium phosphate nanoparticles to reduce metal mobility in shooting range soils

Science of The Total Environment, 571, 2016, 1136–1146

http://dx.doi.org/10.1016/j.scitotenv.2016.07.108

Shooting activities are a very important source of contamination as they are commonly detected high concentrations of Pb in the soils from these facilities. Different remediation methods imply the immobilization of the pollutants by decreasing their mobility and availability and nanotechnology is a promising technique in this field. The effectiveness of calcium phosphate nanoparticles (CPNs) in the remediation of small-arms firing range and trap shooting range soils is evaluated in this work. The operationally defined extractable content of Pb, Cu and Zn is determined together with the interaction of the pollutants with the nanomaterials. Soil samples were treated with the CPNs and after the treatment the extractable contents of Cu, Pb and Zn decrease. To check the retention by the nanoparticles TOF-SIMS (Time of Flight Secondary Ion Mass Spectrometry) and HR-TEM-EDS (High Resolution Transmission Electron Microscopy with Energy Dispersive X-ray Spectroscopy) techniques were applied. The association of Pb and Cu to the CPNs was demonstrated by TOF-SIMS although it also indicated that not all the Pb and Cu contents are linked to the nanoparticles. By means of HR-TEM/EDS it was made out the filamentous shape and the size (50–150 nm long and 20–40 nm wide) of the CPNs together with their elemental composition (Ca, P and O). The CPNs were identified in treated soil samples together with signals of metals. The decrease on metal extractability detected is, in part, due to the association with CPNs but still more investigation is needed regarding mobility and availability of potentially hazardous elements in soils treated with nanoparticles.