Adsorption of cis-dichlorodiammineplatinum by nanostructures based on single-domain magnetite

Magnetosensitive nanocomposites on the basis of monodomain magnetite Fe3O4/meso-2,3-dimercaptosuccinic acid, Fe3O4/c-aminopropyltriethoxysilane, Fe3O4/polyacrylamide, Fe3O4/hydroxyapatite were synthesized. Size distribution of magnetite nanoparticles in ensemble and their magnetic properties were studied. It has been shown that the magnetization curve of the liquid containing monodomain magnetite has a form that is characteristic for superparamagnetics, and its calculations in the framework of Langeven’s paramagnetism theory match satisfactorily to the experimental results. The highest adsorption parameters were observed for magnetosensitive nanocomposites Fe3O4/ polyacrylamide and Fe3O4/c-aminopropyltriethoxysilane. Prospects of the studied nanostructures for medicobiological and technical applications as adsorbents of cis-dichlorodiammineplatinum were shown

A collaborative EDNAP exercise on SNaPshot™-based mtDNA control region typing

A collaborative European DNA Profiling (EDNAP) Group exercise was undertaken to assess the performance of an earlier described SNaPshot™-based screening assay (denoted mini-mtSNaPshot) (Weiler et al., 2016) [1] that targets 18 single nucleotide polymorphism (SNP) positions in the mitochondrial (mt) DNA control region and allows for discrimination of major European mtDNA haplogroups. Besides the organising laboratory, 14 forensic genetics laboratories were involved in the analysis of 13 samples, which were centrally prepared and thoroughly tested prior to shipment. The samples had a variable complexity and comprised straightforward single-source samples, samples with dropout or altered peak sizing, a point heteroplasmy and two-component mixtures resulting in one to five bi-allelic calls. The overall success rate in obtaining useful results was high (97.6%) given that some of the participating laboratories had no previous experience with the typing technology and/or mtDNA analysis. The majority of the participants proceeded to haplotype inference to assess the feasibility of assigning a haplogroup and checking phylogenetic consistency when only 18 SNPs are typed. To mimic casework procedures, the participants compared the SNP typing data of all 13 samples to a set of eight mtDNA reference profiles that were described according to standard nomenclature (Parson et al., 2014) [2], and indicated whether these references matched each sample or not. Incorrect scorings were obtained for 2% of the comparisons and derived from a subset of the participants, indicating a need for training and guidelines regarding mini-mtSNaPshot data interpretation.</p

Lectins: obtaining, properties, application in biology and medicine

The review material belongs to the scientific and practical issues related to the interdisciplinary direction on the border of nanotechnology, surface chemistry and physics, biology and medicine and is based on the use of natural components in the composition of iron-containing bioactive nanocomposites and magnetic fluids in creating effective vector systems for antitumor therapy with minimized side effects on the human body and improved compatibility with other drugs. Such natural components, which have unique properties, significant and not yet realized potential opportunities for practical use, include, in particular, lectins. The aim of the work is to select and analyze the results of works on the extraction of lectins, the study of their properties and application in biology and medicine. Lectins are a group of substances of protein nature (proteins and glycoproteins) of non-immune origin, which have the ability to reversely and selectively bind carbohydrates and carbohydrate determinants of biopolymers without changes in covalent structure and recognize them with extremely high specificity. Due to this property, they are an ideal tool for reading of code in the structure of specific sugar epitopes on the surface of all cells. Lectins are substances of primary synthesis and are present in all kingdoms, types and classes of living organisms. They mediate cellular communication at the molecular level and are involved in many physiological and pathophysiological processes. Pathogenic bacteria and viruses use lectins to attach to the host tissue, which is one of the prerequisites for the development of infection. Blocking of specific pathogen adhesion with lectin inhibitors is the basis of anti-adhesive therapy, an alternative method of treatment of infections caused by multidrug-resistant bacterial strains. Numerous lectins show antitumor activity and are being studied as potential antitumor drugs. To date, they have found practical application in a number of specialized medical fields, such as histology (detection of carbohydrate structures on the surface of cells and tissues), diagnosis of immunodeficiency and chromosomal abnormalities, transplantology (separation of blood cells and lymphoid cells with different antigenic properties). The prospect of use of lectins in the purification of blood from viruses, pathologically altered glycoproteins, in the targeted delivery of drugs to normal or pathologically altered cells and tissues of the body or to infectious agents is considered very significant. The combination of properties of lectins and magnetically sensitive iron-containing nanocomposites in the composition of magnetic fluids for use in oncology is considered relevant and promising.</jats:p

Hydration of bacterial lectin in native state and after immobilization on surface of hydrophobic silica

The aim of the work was to study the peculiarities of interaction of the surface of bacterial lectin of Bacillus subtilis IMB B-7724 inthe native state and under different model conditions with water molecules by 1 H NMR; to create a composite system based on the studied lectin, in which the protein molecule is minimally affected by the surface of the carrier, because protein molecules are capable to bind a significant amount of water localized in the spaces between the polymer chains. A method of “dry” immobilization of bacterial lectin on the surface of hydrophobic silica has been developed. Hydration of native lectin and lectin fixed on the surface of hydrophobic silica AM-1-175 was studied by low-temperature 1 H NMR spectroscopy. It has been shown that the immobilization of lectin on the surface of AM1 is accompanied by an increase in the interfacial energy gS from 4.1 to 5.2 J/g. This is due to an increase in the concentration of strongly bound water. Analysis of changes in the distributions of radii R of clusters of adsorbed water allows us to state that in water adsorbed by native lectin, there are two main maxima at R = 1 and 3 nm. In the immobilized state, the maximum at R = 1 nm is present in both types of water (of different order), but the second maximum is observed only for more ordered associates. Chloroform medium slightly reduces the binding energy of water to native lectin molecules (from 4.3 to 4.1 J/g), but in the case of immobilized lectin in CDCl3 medium, the value of ΣgS increases from 5.2 to 7.4 J/g. That is, the weakly polar medium promotes to increase in the interaction of water with interfaces, which is manifested in a relative increase in the number of water clusters of smaller size (Fig. 4). It should be noted that weakly associated forms of water (signal 3) are also represented by several types of clusters that have a radius in the range R = 1–10 nm, and their size distribution changes significantly during immobilization of lectin on the surface of AM1. Probably, weakly associated types of water are formed both in cavities, between polymer chains of protein molecules, and on the surface of AM1, free of protein.</jats:p