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1.
PVP-stabilized tungsten oxide nanoparticles: pH sensitive anti-cancer platform with high cytotoxicity.
Popov, AL, Han, B, Ermakov, AM, Savintseva, IV, Ermakova, ON, Popova, NR, Shcherbakov, AB, Shekunova, TO, Ivanova, OS, Kozlov, DA, et al
Materials science & engineering. C, Materials for biological applications. 2020;:110494
Abstract
Photochromic tungsten oxide (WO3) nanoparticles stabilized by polyvinylpyrrolidone (PVP) were synthesized to evaluate their potential for biomedical applications. PVP-stabilized tungsten oxide nanoparticles demonstrated a highly selective cytotoxic effect on normal and cancer cells in vitro. WO3 nanoparticles were found to induce substantial cell death in osteosarcoma cells (MNNG/HOS cell line) with a half-maximal inhibitory concentration (IC50) of 5 mg/mL, while producing no, or only minor, toxicity in healthy human mesenchymal stem cells (hMSc). WO3 nanoparticles induced intracellular oxidative stress, which led to apoptosis type cell death. The selective anti-cancer effects of WO3 nanoparticles are due to the pH sensitivity of tungsten oxide and its capability of reactive oxygen species (ROS) generation, which is expressed in the modulation of genes involved in reactive oxygen species metabolism, mitochondrial dysfunction, and apoptosis.
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2.
Study on microstructure, microhardness, bioactivity, and biocompatibility of La2 O3 -containing bioceramic coating doping SiO2 fabricated by laser cladding.
Fu, Q, Liu, Q, Li, L, Li, X, Gu, H, Sheng, B, Yang, B
Journal of biomedical materials research. Part B, Applied biomaterials. 2020;(5):2099-2107
Abstract
To solve the lack of strength of calcium phosphate ceramic coatings in load-bearing applications, gradient Ca-P bioceramic coatings doped with La2 O3 and SiO2 are fabricated by laser cladding on Ti-6Al-4 V. The effect of SiO2 on microstructure, microhardness, bioactivity, and biocompatibility of coatings was investigated. The experimental results illustrate that the coating doped with La2 O3 and SiO2 has excellent metallurgical bonding. The XRD analysis confirms that the amount of hydroxyapatite and tricalcium phosphate in the coating reached maximum when doping amount of SiO2 is 10 wt %. SiO2 -doped coatings show a significantly higher bone-like apatite precipitation after immersion in SBF than that of other coatings. in vitro experiment also shows that coating with 10 wt % SiO2 is more suitable for the attachment and proliferation of MG63 cells, indicating that coating with 10 wt % SiO2 exhibits best bioactivity and biocompatibility. These results suggest that the addition of SiO2 improves the bonding strength, bioactivity, and biocompatibility of coatings.
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3.
Rapid fabrication of electrode for the detection of alpha fetoprotein based on MnO2 functionalized mesoporous carbon hollow sphere.
Zhu, X, Dai, Y, Sun, Y, Liu, H, Sun, W, Lin, Y, Gao, D, Han, R, Wang, X, Luo, C
Materials science & engineering. C, Materials for biological applications. 2020;:110206
Abstract
The concentration of alpha-fetoprotein (AFP) rises greatly in patients with liver cancer and it is a challenge to construct a sensitive AFP detection method with wide range. Therefore, an easy and label-free sensing electrochemical platform for AFP detection with wide concentration range had been designed in this work. Firstly, MnO2 functionalized mesoporous carbon hollow sphere (MCHS@MnO2) with optimal performance was synthesized by regulating experimental conditions and characterized by scanning electron microscope (SEM), high resolution transmission electron microscopy (HRTEM), x-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV), etc. Then, it was immobilized on glassy carbon electrode (MCHS@MnO2/GCE) to build an immunosensor for the detection of AFP. The MCHS@MnO2/GCE can catalyze decomposition of H2O2 to generate electrochemical signal, and the signal will decrease after capturing AFP. Due to good electrocatalytic activity of MCHS@MnO2 to H2O2, the immunosensor achieved indirect detection of AFP with wide sensing range from 0.10 ng mL-1 to 420 ng mL-1 and a detection limit of 0.03 ng mL-1. Furthermore, the method had been proven to be satisfactory selectivity and reproducibility, and it was successfully applied to determine the content of AFP in human serum samples with satisfactory results. This method is expected to be used for early diagnosis and prognosis examination of liver cancer patients.
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4.
Understanding the Solution Behavior of Epinephrine in the Presence of Toxic Cations: A Thermodynamic Investigation in Different Experimental Conditions.
Crea, F, De Stefano, C, Irto, A, Lando, G, Materazzi, S, Milea, D, Pettignano, A, Sammartano, S
Molecules (Basel, Switzerland). 2020;(3)
Abstract
The interactions of epinephrine ((R)-(-)-3,4-dihydroxy-α-(methylaminomethyl)benzyl alcohol; Eph-) with different toxic cations (methylmercury(II): CH3Hg+; dimethyltin(IV): (CH3)2Sn2+; dioxouranium(VI): UO22+) were studied in NaClaq at different ionic strengths and at T = 298.15 K (T = 310.15 K for (CH3)2Sn2+). The enthalpy changes for the protonation of epinephrine and its complex formation with UO22+ were also determined using isoperibolic titration calorimetry: HHL = -39 ± 1 kJ mol-1, HH2L = -67 ± 1 kJ mol-1 (overall reaction), HML = -26 ± 4 kJ mol-1, and HM2L2(OH)2 = 39 ± 2 kJ mol-1. The results were that UO22+ complexation by Eph- was an entropy-driven process. The dependence on the ionic strength of protonation and the complex formation constants was modeled using the extended Debye-Hückel, specific ion interaction theory (SIT), and Pitzer approaches. The sequestering ability of adrenaline toward the investigated cations was evaluated using the calculation of pL0.5 parameters. The sequestering ability trend resulted in the following: UO22+ >> (CH3)2Sn2+ > CH3Hg+. For example, at I = 0.15 mol dm-3 and pH = 7.4 (pH = 9.5 for CH3Hg+), pL0.5 = 7.68, 5.64, and 2.40 for UO22+, (CH3)2Sn2+, and CH3Hg+, respectively. Here, the pH is with respect to ionic strength in terms of sequestration.
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5.
Iron-oxide minerals in the human tissues.
Svobodova, H, Kosnáč, D, Tanila, H, Wagner, A, Trnka, M, Vitovič, P, Hlinkova, J, Vavrinsky, E, Ehrlich, H, Polák, Š, et al
Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine. 2020;(1):1-13
Abstract
Iron is critically important and highly regulated trace metal in the human body. However, in its free ion form, it is known to be cytotoxic; therefore, it is bound to iron storing protein, ferritin. Ferritin is a key regulator of body iron homeostasis able to form various types of minerals depending on the tissue environment. Each mineral, e.g. magnetite, maghemite, goethite, akaganeite or hematite, present in the ferritin core carry different characteristics possibly affecting cells in the tissue. In specific cases, it can lead to disease development. Widely studied connection with neurodegenerative conditions is widely studied, including Alzheimer disease. Although the exact ferritin structure and its distribution throughout a human body are still not fully known, many studies have attempted to elucidate the mechanisms involved in its regulation and pathogenesis. In this review, we try to summarize the iron uptake into the body. Next, we discuss the known occurrence of ferritin in human tissues. Lastly, we also examine the formation of iron oxides and their involvement in brain functions.
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6.
Designing an Artificial Pathway for the Biosynthesis of a Novel Phenazine N-Oxide in Pseudomonas chlororaphis HT66.
Guo, S, Liu, R, Wang, W, Hu, H, Li, Z, Zhang, X
ACS synthetic biology. 2020;(4):883-892
Abstract
Aromatic N-oxides are valuable due to their versatile chemical, pharmaceutical, and agricultural applications. Natural phenazine N-oxides possess potent biological activities and can be applied in many ways; however, few N-oxides have been identified. Herein, we developed a microbial system to synthesize phenazine N-oxides via an artificial pathway. First, the N-monooxygenase NaphzNO1 was predicted and screened in Nocardiopsis sp. 13-12-13 through a product comparison and gene sequencing. Subsequently, according to similarities in the chemical structures of substrates, an artificial pathway for the synthesis of a phenazine N-oxide in Pseudomonas chlororaphis HT66 was designed and established using three heterologous enzymes, a monooxygenase (PhzS) from P. aeruginosa PAO1, a monooxygenase (PhzO) from P. chlororaphis GP72, and the N-monooxygenase NaphzNO1. A novel phenazine derivative, 1-hydroxyphenazine N'10-oxide, was obtained in an engineered strain, P. chlororaphis HT66-SN. The phenazine N-monooxygenase NaphzNO1 was identified by metabolically engineering the phenazine-producing platform P. chlororaphis HT66. Moreover, the function of NaphzNO1, which can catalyze the conversion of 1-hydroxyphenazine but not that of 2-hydroxyphenazine, was confirmed in vitro. Additionally, 1-hydroxyphenazine N'10-oxide demonstrated substantial cytotoxic activity against two human cancer cell lines, MCF-7 and HT-29. Furthermore, the highest microbial production of 1-hydroxyphenazine N'10-oxide to date was achieved at 143.4 mg/L in the metabolically engineered strain P3-SN. These findings demonstrate that P. chlororaphis HT66 has the potential to be engineered as a platform for phenazine-modifying gene identification and derivative production. The present study also provides a promising alternative for the sustainable synthesis of aromatic N-oxides with unique chemical structures by N-monooxygenase.
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7.
Mechanisms of mass transfer enhancement by phase-transfer catalysis for permanganate oxidizing dense non-aqueous phase liquid (DNAPL) TCE.
Zhang, M, Dong, J, Cai, P
Chemosphere. 2020;:124867
Abstract
Phase transfer catalysts (PTCs) have been shown to be effective in lowering the limitation of mass transfer between aqueous oxidant MnO4- and NAPLs in in-situ chemical oxidation (ISCO) technologies for remediation of NAPLs. This work researched the effects of pentyltriphenylphosphonium bromide (PTPP, used as the representative PTC) for the enhancement of TCE oxidation, the extent of different treatment effects contributions and generalizability of phase transfer. Experimental results revealed that MnO4- exchanged with Br- in PTPP by ion exchange mechanism and then transferred to NAPL phase due to biphasic nature of PTPP-MnO4-. PTPP enhanced TCE dissolution in aqueous phase but had no significant effect on TCE solubilization. Enhanced TCE dissolution gradually weakened after 2.0 h and disappeared after 5.5 h, while the percentage of MnO4- in phase transfer was 14.8% at 7.5 h, which indicated that dissolution acceleration was only effective at initial stage of reaction (0-2.5 h). Therefore, persistent phase transfer process played the leading role in TCE remediation enhancement. Moreover, for different NAPL phase, more effective phase transfer could be achieved in NAPLs with higher solubility and weaker hydrophobicity. The best-fit polynomial relationship (R2 = 0.992) existed between the percentage amount of MnO4- transferred and the solubility of NAPL.
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8.
Evaluation of Resin-Based Material Containing Copaiba Oleoresin (Copaifera Reticulata Ducke): Biological Effects on the Human Dental Pulp Stem Cells.
Couto, RSD, Rodrigues, MFSD, Ferreira, LS, Diniz, IMA, Silva, FS, Lopez, TCC, Lima, RR, Marques, MM
Biomolecules. 2020;(7)
Abstract
The purpose of this study was to analyze in vitro the biological effects on human dental pulp stem cells triggered in response to substances leached or dissolved from two experimental cements for dental pulp capping. The experimental materials, based on extracts from Copaifera reticulata Ducke (COP), were compared to calcium hydroxide [Ca(OH)2] and mineral trioxide aggregate (MTA), materials commonly used for direct dental pulp capping in restorative dentistry. For this, human dental pulp stem cells were exposed to COP associated or not with Ca(OH)2 or MTA. Cell cytocompatibility, migration, and differentiation (mineralized nodule formation (Alizarin red assay) and gene expression (RT-qPCR) of OCN, DSPP, and HSP-27 (genes regulated in biomineralization events)) were evaluated. The results showed that the association of COP reduced the cytotoxicity of Ca(OH)2. Upregulations of the OCN, DSPP, and HSP-27 genes were observed in response to the association of COP to MTA, and the DSPP and HSP-27 genes were upregulated in the Ca(OH)2 + COP group. In up to 24 h, cell migration was significantly enhanced in the MTA + COP and Ca(OH)2 + COP groups. In conclusion, the combination of COP with the currently used materials for dental pulp capping [Ca(OH)2 and MTA] improved the cell activities related to pulp repair (i.e., cytocompatibility, differentiation, mineralization, and migration) including a protective effect against the cytotoxicity of Ca(OH)2.
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9.
Dechlorination of 2,4,4'-trichlorobiphenyl by magnetoferritin with different loading factors.
Balejcikova, L, Tomasovicova, N, Zakutanska, K, Batkova, M, Kovac, J, Kopcansky, P
Chemosphere. 2020;:127629
Abstract
Polychlorinated biphenyls are synthetic industrial organic substances. These persistent pollutants occur in nature causing high ecological risks and damage to human health. Magnetoferritin nanoparticles composed of apoferritin protein shell surrounding synthetically prepared iron-based nanoparticles seem to be a promising candidate for polychlorinated biphenyls elimination. Properties of magnetoferritin, as a redox activity, a biocompatible character, high application possibilities and a close relationship with the human body promoted ours in vitro investigation of the magnetoferritin catalytic activity in the presence of representative 2,4,4'-trichlorobiphenyl. Basic physico-chemical properties of magnetoferritin were determined by ultraviolet and visible spectrophotometry, dynamic light scattering, zeta potential measurements, superconducting quantum interference device magnetometry and atomic force microscopy. The remediation effect of magnetoferritin on 2,4,4'-trichlorobiphenyl was demonstrated by the use of gas chromatography in combination with infrared spectroscopy.
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10.
Bright Mn-doped carbon dots for the determination of permanganate and L-ascorbic acid by a fluorescence on-off-on strategy.
Chu, X, Ning, G, Zhou, Z, Liu, Y, Xiao, Q, Huang, S
Mikrochimica acta. 2020;(12):659
Abstract
A one-pot hydrothermal synthesis of manganese-doped carbon dots (Mn-CDs) is reported for fluorescent "on-off-on" determination of Mn(VII) and L-ascorbic acid (L-AA) in aqueous solution and living cells. Mn-CDs were prepared by using sulfanilic acid, tetrakis(hydroxymethyl)phosphonium chloride, and Mn(II) chloride as precursors. Mn-CDs were characterized by several spectroscopic methods and microscopic techniques. Mn-CDs show distinctly long fluorescence lifetime (12.39 ± 0.07 ns) and high absolute fluorescence quantum yield (around 37%) with excitation and emission wavelengths of 362 and 500 nm, respectively. Mn-CDs exhibit no significant cytotoxicity to human cervical carcinoma HeLa cells and human embryonic kidney HEK-293T cells at 200 μg mL-1 level after 48 h incubation. The fluorescence of Mn-CDs at 500 nm (excited at 362 nm) is quenched efficiently by Mn(VII) and can be further recovered after the addition of L-AA, resulting in a fluorescent "on-off-on" assay for the determination of Mn(VII) and L-AA. Under optimal experimental conditions, the linear response covers the 3 to 150 μM Mn(VII) concentration range and the 3 to 140 μM L-AA concentration range. This method offers relatively low detection limits of 0.66 μM for Mn(VII) and 0.90 μM for L-AA. This strategy was applied to visual determination of Mn(VII) and L-AA in living HeLa cells with satisfying results. Graphical abstract Schematic presentation of bright Mn-CD-based fluorescence "on-off-on" assay for both Mn(VII) and L-AA. This fluorescent assay possessed low detection limit of 0.66 μM for Mn(VII) and 0.90 μM for L-AA. This strategy was applied for visual determination of Mn(VII) and L-AA in living HeLa cells with satisfying results.