Organotin(IV)‐Loaded Mesoporous Silica as a Biocompatible Strategy in Cancer Treatment

The strong therapeutic potential of an organotin(IV) compound loaded in nanostructured silica (SBA‐15pSn) is demonstrated: B16 melanoma tumor growth in syngeneic C57BL/6 mice is almost completely abolished. In contrast to apoptosis as the basic mechanism of the anticancer action of numerous chemotherapeutics, the important advantage of this SBA‐15pSn mesoporous material is the induction of cell differentiation, an effect unknown for metal‐based drugs and nanomaterials alone. This non‐aggressive mode of drug action is highly efficient against cancer cells but is in the concentration range used nontoxic for normal tissue. JNK (Jun‐amino‐terminal kinase)‐independent apoptosis accompanied by the development of the melanocyte‐like nonproliferative phenotype of survived cells indicates the extraordinary potential of SBA‐15pSn to suppress tumor growth without undesirable compensatory proliferation of malignant cells in response to neighboring cell death.     

Effect of Vitamin B Complex Treatment on Macrophages to Schwann Cells Association during Neuroinflammation after Peripheral Nerve Injury

Peripheral nerve injury (PNI) triggers a complex multi-cellular response involving the injured neurons, Schwann cells (SCs), and immune cells, often resulting in poor functional recovery. The aim of this study was to investigate the effects of the treatment with vitamin B (B1, B2, B3, B5, B6, and B12) complex on the interaction between macrophages and SCs during the recovery period after PNI. Transection of the motor branch of the femoral nerve followed by reconstruction by termino-terminal anastomosis was used as an experimental model. Isolated nerves from the sham (S), operated (O), and operated groups treated with the B vitamins (OT group) were used for immunofluorescence analysis. The obtained data indicated that PNI modulates interactions between macrophages and SCs in a time-dependent manner. The treatment with B vitamins complex promoted the M1-to M2-macrophage polarization and accelerated the transition from the non-myelin to myelin-forming SCs, an indicative of SCs maturation. The effect of B vitamins complex on both cell types was accompanied with an increase in macrophage/SC interactions, all of which correlated with the regeneration of the injured nerve. Clearly, the capacity of B vitamins to modulate macrophages-SCs interaction may be promising for the treatment of PNI.     

In vivo solid-phase microextraction in metabolomics: opportunities for the direct investigation of biological systems

Sample preparation has a strong impact on the quality of metabolomics studies. The use of solid-phase microextraction (SPME), particularly its in vivo format, enables the capture of a more representative metabolome and presents opportunities to detect low-abundance, short-lived, and/or unstable species not easily captured by traditional methods. The technique is ideally suited for temporal, spatial, and longitudinal studies of the same living system, as well as multicompartmental studies of the same organism. SPME is useful for the investigation of biological systems ranging in complexity from cells to mammalian tissues. Selected examples are highlighted in this Minireview in order to place the technique within the context of conventional methods of sample preparation for metabolomics.     

Magnetically induced controlled release from glucose-modified liposomes loaded with Fe3O4 nanoparticles

Journal of Nanoparticle Research - Nd–Fe–B magnetic materials were prepared using the binary alloy method with addition of Ho nanopowder to grain boundaries to improve the magnetic,...     

Dynamic model of methane–water diffusion

This paper presents a mathematical model to describe the time evolution of the diffusion process of methane exchange between liquid and gaseous phases. In order to reach the equilibrium, the distribution of gas in the liquid phase decreases to a constant value over time. Generalized model is analyzed under the assumption that both, reversible and irreversible form of absorption and desorption, occur at the same time. For the application in case of the real system of methane–water, model is developed under the assumption that the processes of absorption and desorption are irreversible. From the experimental data are determined the coefficients of model and their dependence on initial conditions, with constant end conditions. This paper tests the introduced theoretical model on the existing experimental data.     

Half-sandwich ruthenium(II)-arene complexes: synthesis,spectroscopic studies,biological properties,and molecular modeling

In search for antitumor metal-based drugs that would mitigate the severe side-effects of cisplatin, Ru(II) complexes are gaining increasing recent interest. In this work, we report on the synthesis, characterization (¹H- and ¹³C-NMR, FT-IR), and cytotoxicity studies of two new half-sandwich organometallic Ru(II) complexes of the general formula [Ru(η⁶-arene)(XY)Cl](PF₆) where arene?=?benzene or toluene and XY?=?bidentates: dipyrido[3,2-a:2′,3′-c]phenazine (dppz) or 2-(9-anthryl)-1H-imidazo[4,5-f][1,10]phenanthroline (aip), which are bound to Ru(II) via two phenanthroline-N atoms in a characteristic “piano-stool” configuration of Ru(II)-arene complexes—as confirmed by vibrational and NMR spectra. In addition, cytotoxic studies were performed for similar half-sandwich organometallic [Ru(η⁶-p-cymene)(Me₂dppz)Cl]PF₆ complex (Me₂dppz = 11,12-dimethyl-dipyrido[3,2-a:2′,3′-c]phenazine). This study is complemented with elaborate modeling with density functional theory (DFT) calculations, which provided insight into reactive sites of Ru(II) structures, further detailed by molecular docking on the B-DNA dodecamer, which identified binding sites and affinities: most pronounced for the [Ru(η⁶-benzene)(aip)Cl](PF₆) in both A-T and G-C regions of the DNA minor groove. Cytotoxic activity was probed versus tumor cell lines B16, C6, and U251 (B16 mouse melanoma, C6 rat glioma, U251 human glioblastoma) and non-tumor cell line HACAT (HACAT normal human keratinocytes).     

Oxidative transformations of 4‐methylcoumarins using dimethyldioxirane

Efficient regioselective oxidation of the double C? C bond of 4‐methylcoumarins with isolated dimethyldioxirane was performed, and related hydroxy and epoxy derivatives were obtained in good yields. All of obtained epoxides and most of hydroxy derivatives are novel compounds. The position of different electron‐donating groups attached at the aromatic part of molecule shows significant influence on kinetics and course of the reaction. J. Heterocyclic Chem., (2011).     

Binuclear dichlorido(η6‐p‐cymene)ruthenium(II) complexes with bis(nicotinate)‐ and bis(isonicotinate)‐polyethylene glycol ester ligands

Neutral binuclear ruthenium complexes 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 of the general formula [{RuCl₂(η⁶‐p‐cym)}₂ μ‐(N^∩N)] (N^∩N = bis(nicotinate)‐ and bis(isonicotinate)‐polyethylene glycol esters: (3‐py)COO(CH₂CH₂O)_nCO(3‐py) and (4‐py)COO(CH₂CH₂O)_nCO(4‐py), n =1–4), as well as mononuclear [RuCl₂(η⁶‐p‐cym)((3‐py)COO(CH₂CH₂OCH₃)‐κN)], complex 9 , were synthesized and characterized using elemental analysis and electrospray ionization high‐resolution mass spectrometry, infrared, ¹H NMR and ¹³C NMR spectroscopies. Stability of the binuclear complexes in the presence of dimethylsulfoxide was studied. Furthermore, formation of a cationic complex containing bridging pyridine‐based bidentate ligand was monitored using ¹H NMR spectroscopy. Ligand precursors, polyethylene glycol esters of nicotinic ( L1 · 2HCl– L4 · 2HCl and L9 · HCl) and isonicotinic acid dihydrochlorides ( L5 · 2HCl– L8 · 2HCl), binuclear ruthenium(II) complexes 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 and mononuclear complex 9 were tested for in vitro cytotoxicity against 518A2 (melanoma), 8505C (anaplastic thyroid cancer), A253 (head and neck tumour), MCF‐7 (breast tumour) and SW480 (colon carcinoma) cell lines. Copyright © 2014 John Wiley & Sons, Ltd.