We report here the successful use of a protozoan model organism P. caudatum to investigate the toxicity of clay nanoparticles (montmorillonite, halloysite, kaolin, and bentonite), silica nanospheres and graphene oxide nanoflakes.

Hollow halloysite nanotubes have been used as nanocontainers for loading and for the triggered release of calcium hydroxide for paper preservation. A strategy for placing end-stoppers into the tubular nanocontainer is proposed and the sustained release from the cavity is reported. The incorporation of Ca(OH)2 into the nanotube lumen, as demonstrated using transmission electron microscopy (TEM) imaging and Energy Dispersive X-ray (EDX) mapping, retards the carbonatation, delaying the reaction with CO2 gas. This effect can be further controlled by placing the end-stoppers. The obtained material is tested for paper deacidification. We prove that adding halloysite filled with Ca(OH)2 to paper can reduce the impact of acid exposure on both the mechanical performance and pH alteration. The end-stoppers have a double effect: they preserve the calcium hydroxide from carbonation, and they prevent from the formation of highly basic pH and trigger the response to acid exposure minimizing the pH drop-down. These features are promising for a composite nanoadditive in the smart protection of cellulose-based materials.

The increasing number of reports about false positive or negative results from conventional cytotoxicity assays of nanomaterials (NMs) suggests that more reliable NM toxicity assessment methods should be developed. Here, we report a novel approach for nanotoxicity evaluation based on surface-enhanced Raman spectroscopy (SERS). Three model NMs were tested on two model cell lines and the results were validated by WST-1 cytotoxicity assay and annexin V-FITC/propidium iodide (PI) staining as apoptosis-necrosis assay. The localization of nanoparticles (NPs) in the cells and the cellular conditions upon NP incubation were visualized by transmission electron microscopy (TEM) and enhanced dark-field (EDF) microscopy. SERS revealed a broader view on the consequences of cell-NM interactions compared to the conventional cytotoxicity assays where only one aspect of toxicity can be measured by one assay type. The results suggest that SERS can significantly contribute to the cytotoxicity evaluation bypassing NM or assay component-related complications with less effort.

Cadmium (Cd) and lead (Pb) are heavy metals, important environmental pollutants, and potent toxicants to organism. Lactic acid bacteria (LAB) have been reported to remove Cd and Pb from solutions and therefore represent a useful tool for decontamination of food and beverages from heavy metals. Heavy metal ion binding by LAB was reported as metabolism-independent surface process. In this work ten Lactobacillus strains were investigated with respect to hydrophobicity, Lewis acid-base, and electrostatic properties of their outer cell surface in order to characterize their Cd and Pb removal capacity. Seven L. plantarum and L. fermentum strains were shown to remove Cd from culture medium. The metabolism-dependent accumulation mechanism of Cd removal was proposed based on extended character of Cd binding and lack of correlation between any of the surface characteristics and Cd removal. The results of this study should be considered when selecting probiotic strains for people at risk of Cd exposure.

New Findings r What is the central question of this study?Variations in genes are considered to be molecular determinants maintaining the expression of the slow or fast myosin heavy chains of adult skeletal muscle. The role of polymorphisms of candidate genes involved in skeletal muscle development, energy homeostasis and thyroid and calcium metabolism in the determination of muscle fibre type has not previously been reported. r What is the main finding and its importance?We show that the AGTR2 rs11091046 C allele is associated with an increased proportion of slow-twitch muscle fibres, endurance athlete status and aerobic performance. Such findings have important implications for our understanding of muscle function in both health and disease.Muscle fibre type is a heritable trait and can partly predict athletic success. It has been proposed that polymorphisms of genes involved in the regulation of muscle fibre characteristics may predispose the muscle precursor cells of a given individual to be predominantly fast or slow. In the present study, we examined the association between 15 candidate gene polymorphisms and muscle fibre type composition of the vastus lateralis muscle in 55 physically active, healthy men. We found that rs11091046 C allele carriers of the angiotensin II type 2 receptor gene (AGTR2; involved in skeletal muscle development, metabolism and circulatory homeostasis) had a significantly higher percentage of slow-twitch fibres than A allele carriers [54.2 (11.1) versus 45.2 (10.2)%; P = 0.003]. These data indicate that 15.2% of the variation in muscle fibre composition of the vastus lateralis muscle can be explained by the AGTR2 genotype. Next, we investigated the frequencies of the AGTR2 alleles in 2178 Caucasian athletes and 1220 control subjects. The frequency of the AGTR2 C allele was significantly higher in male and female endurance athletes compared with power athletes (males, 62.7 versus 51.7%, P = 0.0038; females, 56.6 versus 48.1%, P = 0.0169) and control subjects (males, 62.7 versus 51.0%, P = 0.0006; elite female athletes, 65.1 versus 55.2%, P = 0.0488). Furthermore, the frequency of the AGTR2 A allele was significantly over-represented in female power athletes (51.9%) in comparison to control subjects (44.8%, P = 0.0069). We also found that relative maximal oxygen consumption was significantly greater in male endurance athletes with the AGTR2 C allele compared with AGTR2 A allele carriers [n = 28; 62.3 (4.4) versus 57.4 (6.0) ml min −1 kg −1 ; P = 0.0197]. Taken together, these results demonstrate that the AGTR2 gene C allele is associated with an increased proportion of slow-twitch muscle fibres, endurance athlete status and aerobic performance, while the A allele is associated with a higher percentage of fast-twitch fibres and power-oriented disciplines.