Iron oxide nanoparticles (IONPs) are one of the most promising types of nanoparticles for both biotechnological (e.g. enzyme immobilization, targeted cell/macromolecules separation and purification, cell labeling and sorting, magnetofection etc.) and biomedical (contrast agents in MRI, heating mediators in hyperthermia-based cancer therapy, nanocarriers in targeted drug/gene delivery etc.) applications. Moreover, IONPs are in the center of an intensive research focusing on combining the therapeutic and diagnostic functions within a single nanostructure, to build theranostic nanocarriers. IONPs are relatively easily manufactured, biocompatible and non-toxic, chemically rather stable and can be superparamagnetic. The benefit of IONPs in biomedicine is obvious therefore the fate of IONPs following their therapeutic or diagnostic application generates a necessity to thoroughly investigate their potential negative impact on human health. To address this task, various surface-modified magnetite nanoparticles were synthetized and characterized in-depth using different physico-chemical methods. Their stability in culture medium was analyzed by the DLS and the uptake was visualized by TEM and quantified by AAS/ICP-MS. To objectively consider the biosafety of IONPs, several in vitro methods were employed to evaluate comprehensively their potential negative adverse effects. Our data indicate that oxidative stress plays, at most, only a marginal role in the biological activity of IONPs in A549 cells. Moreover, they may act as aneugen-like spindle poisons causing mitotic slippage and chromosome malsegregation via interference with tubulin polymerization. The microtubule destroying capacity of IONPs might increase the therapeutic effects IONP-based anti-cancer drugs; however their potential negative impact on normal cells should be investigated very carefully.
Acknowledgements. This study was supported by the VEGA grants 2/0143/13 and 2/0113/15, by the grant through the EEA FM and the NFM (project SK0020), and by European Union`s Horizon 2020 (H2020/2014-2020) under grant agreement no. 685817 – HISENTS. Bábelová A. and Rázga F. are receiving support within the SASPRO Programme (projects No. 0084/01/02 and 0057/01/02) co-funded by the European Union and the Slovak Academy of Sciences. The authors would like to acknowledge the contribution of the COST Action CA15132 (hCOMET).
The increased use of nanoparticles (NP) and nanomaterials is pushing scientific research into trying to understand the mechanisms governing interactions between biomolecules and inorganic materials. It is known that, once an NP is in contact with a biological medium, a protein corona forms on its surface [1], and that the nature of the corona is what regulates the interaction between the NP and the other biomolecules.
We aim to construct a coarse-grained model for the interaction of an arbitrary protein with common industrial nanomaterials.
The protein in this model is represented by one bead per aminoacid, and interaction of each aminoacid with the NP surface is described by a potential of mean force (PMF) from atomistic simulations [2]. The 3D structure of the protein is obtained from the corresponding code in the Protein Data Bank (PDB). The NP is represented by a two-layer model, where the surface beads interact with aminoacid-bead potential that is obtained by fitting from all-atomistic calculations, while the core interacts with the aminoacids via van der Waals forces calculated using Lifshitz theory and is represented by a single bead. This model can describe the protein adsorption energies on the surface of NPs of arbitrary size and of any material available, provided an all-atomistic PMF of aminoacids with flat surface of the material is available and the refractive indices for modeling the protein-NP core attraction are known.
We calculate protein adsorption energies for representative proteins such as α-1-antitrypsin, lysozyme, human serum albumin and nanomaterials (Au and TiO2) for NPs of different size. We discuss the implications of the variation of the attraction energy with NP size for the protein corona content.
Funding: H2020 grant SmartNanotox, contract No. 686098
REFERENCES: [1] M. Rahman, S. Laurent, N. Tawil, L. Yahia, and M. Mahmoudi. Protein-Nanoparticle Interactions, volume 15 of Springer Series in Biophysics. Springer-Verlag, 2013; [2]
E. Brandt and A. P. Lyubartsev. Molecular dynamics simulations of adsorption of amino acid side chain analogues and a titanium binding peptide on the TiO2 (100) surface. J. Phys. Chem. C, 119:18126, 2015.
We analyzed gene expression changes in the lungs and the immunological response in splenocytes of mice exposed by inhalation of ZnO nanoparticles (NP). Adult female ICR mice were treated for three days and three months, respectively. Analysis of differential expression and alternative splicing (AS) events in genes involved in oxidative stress, immune response, inflammation, apoptosis, DNA damage and repair, and cell cycle regulation was conducted using next-generation sequencing. The potential immunotoxic and immunomodulatory effects of ZnO NP were analyzed by phenotyping and cytokine production by splenocytes after three months exposure. Three days exposure resulted in the up-regulation of IL-6 and down-regulation of BID, GSR, NF-kB2, PTGS2, SLC11A2, and TXNRD1 mRNA expression; three months exposure increased the expression of ALDH3A1, APAF1, BID, CASP3, DHCR7, GCLC, GCLM, GSR, GSS, EHHADH, FAS, HMOX-1, IFN, NF-kB1, NQO-1, PTGS1, PTGS2, RAD51, RIPK2, SRXN1, TRAF6 and TXNRD1 mRNA. AS of TRAF6 and TXNRD1 genes was induced after three days exposure. Three months exposure caused a significant decrease in the percentage of granulocytes in the spleen cells, and affected the production of IL-10 and IL-6 by lipopolysaccharide-stimulated leukocytes. In summary, our study revealed changes in the expression of genes involved in the oxidative stress response, apoptosis, immune response, inflammation and DNA repair, as well as induction of AS in genes associated with oxidative stress and inflammation following ZnO NP exposure. Subchronic ZnO NP exposure induced immunomodulatory effects in the spleen. Supported by the Ministry of Youth, Education and Sports CR (LO1508) and the Czech Science Foundation (P503/12/G147).
Carbon nanotubes (CNT) have number of unique properties which make them promising for many medicine applications including their intravascular use. Biocompatibility of CNT with blood cells and endothelial lining of blood vessels thus represent critical safety issue. In the blood, the surface of CNT is quickly covered with plasma proteins and other biomolecules forming a protein corona which affects biological properties of the CNT. We have investigated the interactions of carboxylated-multiwalled carbon nanotubes (CNTCOOH) with common human proteins including albumin (HSA) and γ-globulins (IgG) and studied the effect of the corona composition on the interaction of CNTCOOH with human blood platelets and endothelial cells in vitro. We found that the identity of protein forming the corona greatly affects the outcome of CNTCOOH-cells interactions. Bare CNTCOOH induced platelet aggregation and release of platelet membrane microparticles. HSA corona attenuated the platelet aggregating activity of CNTCOOH, while the IgG corona caused profound platelet fragmentation. To study the toxicity of CNTCOOH in cultured human umbilical vein endothelial cells (HUVEC) we have designed a "three in one" screening assay allowing assessment of different types of cell death. The assay consists of WST-8, LDH and Hoechst 33342 staining, all performed in one well, which enables evaluation of cell viability, necrosis and apoptosis, respectively, of the same cell sample. Similarly as in platelets, HSA corona had protective effect against CNTCOOH toxicity while IgG corona aggravated the cellular toxicity of CNTCOOH towards HUVEC. Our study points on crucial importance of protein corona composition on cellular toxicity of CNTCOOH.
The paper evaluates the filtration and sorption efficiency of selected types of military combined filters using the methodology and instrumentation introduced in the accredited laboratories of the Institute of Analytical Chemistry of the Czech Academy of Sciences. The testing was carried out with the use of ultra-fine aerosol containing lead oxide nanoparticles ranging in size from 7.64 nm to 299.60 nm. Nanoparticles were generated in situ in a hot flow tubular reactor using the evaporation-oxidation-condensation technique. The resulting metal vapours were oxidised to lead oxide after dilution with air. During the measurement, the aerosol flow rate was set to 95 l/min. The measurements of nanoparticles were carried out using a scanning mobility particle sizer before and after the passage through the filter and a specially developed sampling device at two levels of concentration.
The basic parameters of permeability of ultra-fine aerosols passing through the tested material were evaluated, in particular particle size, mass and volume distribution, efficiency of nanoparticle capture by filter, nanoparticle penetration through filter, pressure drop and overall filtration efficiency. The measurement results obtained have showed that the filtration efficiency over the entire measured range of nanoparticles was sufficient; however, it was different for particular particle sizes. The reason is probably the combination of surface and depth particle trapping mechanisms. The results of the paper will be used for evaluating the quality of the military protection filters used in the Armed Forces of the Czech Republic in military training and in the course of work of the specialized workplaces of military formations. The structure of filters used in the Fire Rescue Service is very similar to that of the military filters. The results, therefore, will also be used in the field of safety.
Nanoparticles (NPs), that are characterized by the size range of up to 100 nm, may be toxic even though the corresponding bulk material can be safe. The first reason for the toxicity of nanoparticles is their dimension – they are so small that they easily enter the body through the alveolas in the lungs when inhaled, through pores in the gut when ingested or through the pores in the skin. Due to their small dimension, NPs can enter such parts of the body where the counterpart bulk materials cannot occur. If the nanomaterials are biopersistent, they can accumulate in various organs. The second reason for their toxicity is their great surface energy due to unsatisfied chemical bonds at their surface which brings about their strong interaction with the surrounding biological matrix [1].
Within the project HISENTS, the sensor platform for nanotoxicity is developed. The platform will include DNA, miRNA, biomembrane, single cell, lung, intestine, liver, kidney and placenta modules. Toxicity of nanoparticles is related to their concentration in the organ under consideration and time of exposure. Both, the concentration and exposure time, can be estimated from physiologically based pharmacokinetic (PBPK) modeling [2]. The PBPK model enables to describe the ADME (absorption, distribution, metabolism, excretion) process and, hence, to predict the concentration of NPs in the organs and time of exposure. Kinetic and thermodynamic parameters needed for modeling will be obtained from the sensor response. Knowing the concentration and time of exposure, the type of toxicity and damage of cells will be assessed. ACKNOWLEDGEMENTS: This work is financed by the project No. H2020-NMP-685817 High level Integrated SEnsor for NanoToxicity Screening (HISENTS). REFERENCES: [1] P.Šimon, E.Joner J. Food Nutr. Res. 2008, 47, 51-59.; [2] M. Li, K.T. Al-Jamal, K.Kostarelos, J.Reineke ACS Nano 2010, 4, 6303-6317.
Nanomaterials, owing to their unique material properties and activities, are popular for applications involving the detection and diagnosis of genetic and life-threatening illnesses, such as cancer. However, there is an academic and public concern over nanomaterial toxicity and their long-term adverse effects on the immune system. The SmartNanoTox team, comprising academic and industrial experts in in-vivo toxicity, was established to resolve the intricate mechanisms underlying nanotoxicity, and provide an efficient approach to predict the toxicity of nanomaterials.