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Wang J, Ottosson J, Tentarelli S. Development of hydrolytic stability screening methods for early drug discovery with high differentiation and predictive power. J Pharm Biomed Anal 2023; 233:115478. [PMID: 37245329 DOI: 10.1016/j.jpba.2023.115478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/06/2023] [Accepted: 05/22/2023] [Indexed: 05/30/2023]
Abstract
In early drug discovery, hydrolytic chemical stability is routinely assessed to ensure future developability of quality compounds and stability in in vitro test environments. When conducting high-throughput hydrolytic stability analyses as part of the compound risk assessment, aggressive conditions are typically applied to allow for faster screening. However, it can be challenging to extrapolate the real stability risk and to rank compounds due to over-estimating risk based on aggressive conditions and the narrow discriminative window. In this study, critical assay parameters including temperature, concentration, and detection technique were systematically assessed using selected model compounds, and the impact and interplay of these parameters on predictive power and prediction quality were evaluated. Improved data quality was achieved using high sample concentration and reduced temperature, combined with ultraviolet (UV) detection, while mass spectrometry (MS) detection was found to be a useful complementary detection technique. Therefore, a highly discriminative stability protocol with optimized assay parameters and experimental data quality is proposed. The optimized assay can provide early guidance on the potential stability risk of a drug molecule as well as enable more confident decision-making in compound design, selection, and development.
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Affiliation(s)
- Jianyan Wang
- Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, Boston, USA.
| | - Jenny Ottosson
- Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, Gothenburg, Sweden
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Afra S, Atai M, Yeganeh H, Ziaee F. Synthesis, characterization, photo-polymerization, hydrolytic stability, and etching behavior of new self-etch adhesive monomers. J Mech Behav Biomed Mater 2023; 139:105693. [PMID: 36731189 DOI: 10.1016/j.jmbbm.2023.105693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 02/03/2023]
Abstract
Considering the poor hydrolytic stability of the most methacrylate-based functional monomers of self-etch dental adhesives in acidic and aqueous conditions, in this study allyl-based photo-polymerizable self-etch monomers was synthesized in order to improve the hydrolytic stability. The new self-etch monomers based on phosphonic acid functional groups were synthesized through a two-step procedure. First, phosphoric anhydride, poly-phosphoric acid, and polyethylene glycol were reacted to produce phosphate ester precursor (P-PEG-P). Next, allyl 2, 3-epoxypropyl ether was reacted with P-PEG-P to synthesize allyl self-etch monomer. Glycidyl methacrylate was also reacted with P-PEG-P to synthesize a methacrylate self-etch analogue monomer. The monomers were characterized using FTIR and 1H-NMR spectroscopy. The viscosities of monomers were measured using a rheometer. The degree photopolymerization conversion of monomers was measured using FTIR spectroscopy. The pH assay was performed by a digital pH-meter. The etching behavior of the monomers on human teeth was studied using scanning electron microscopy (SEM). Thermo-gravimetric analysis (TGA) was performed to evaluate the possible interaction of the monomers with tricalcium phosphate (TCP). The solubility of synthesized monomers was examined in ethanol, acetone, and water. The hydrolytic stability of cured resins in artificial saliva during 4 months was also surveyed. The synthesis of new self-etching monomers was successfully confirmed by spectroscopy analyses. The results represented appropriate viscosity of self-etching monomers around 1 (Pa s). The resin containing methacrylate monomer exhibited its degree of conversion is more than that of allyl monomer (p < 0.05). The allyl and methacrylate self-etch monomers exhibited pH values of 1.2 and 1.3, respectively. SEM micrograph verified that the synthesized monomers were able to suitable etching of the enamel human premolar teeth. The data obtained from TGA tests revealed that thermal stability of (TCP) containing monomers is enhanced. Also, the monomers exhibited an excellent solubility in polar solvents, but when they are mixed with TCP, they are not, anymore, dissolved in these solvents. Furthermore, the allyl monomer showed higher hydrolytic stability than the methacrylate monomer. The new photo-polymerizable acidic monomer based on allyl functionality showed enhanced hydrolytic stability compared to methacrylate-based monomer. It may be considered as a promising monomer for self-etch dental adhesives.
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Mikolaichuk OV, Popova EА, Protas AV, Shemchuk OS, Vasina LV, Pavlyukova YN, Potanin AA, Molchanov OЕ, Maistrenko DN, Semenov KN, Sharoyko VV. Study of biocompatibility, cytotoxic activity in vitro of a tetrazole-containing derivative of 2-amino-4,6-di(aziridin-1-yl)-1,3,5-triazine. Biochem Biophys Res Commun 2022; 629:176-82. [PMID: 36148694 DOI: 10.1016/j.bbrc.2022.08.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/14/2022] [Accepted: 08/24/2022] [Indexed: 11/22/2022]
Abstract
The hydrolytic stability, hemocompatibility, antioxidant properties and in vitro cytotoxic activity of {5-[(4,6-di(aziridin-1-yl)-1,3,5-triazin-2-yl)amino]-2,2-dimethyl-1,3-dioxan-5-yl}methyl 2-(5-phenyl-2H-tetrazol-2-yl)acetate have been studied. 1H NMR spectroscopy showed that this tetrazole-containing derivative of 1,3,5-triazine is stable in neutral (pH 7) and alkaline (pH 10) media; hydrolysis of the dioxane cycle occurs in an acidic environment (pH 3). It has been established that {5-[(4,6-di(aziridin-1-yl)-1,3,5-triazin-2-yl)amino]-2,2-dimethyl-1,3-dioxan-5-yl}methyl-2-(5-phenyl-2H-tetrazol-2-yl)acetate is hemocompatible, exhibits antioxidant properties, but does not show antiradical activity over the entire range of concentrations. In turn, the study of cytotoxic activity in vitro showed that the tetrazole-containing derivative of 1,3,5-triazine has an effect on the cell lines of human alveolar basal epithelium adenocarcinoma A549 (IC50 41.3 μmol l-1), human ovarian teratocarcinoma PA-1 (IC50 10.6 μmol l-1), hepatocarcinoma Huh7 (IC50 19.9 μmol l-1), cervical cancer HeLa (IC50 3.7 μmol l-1), and human embryonic kidney HEK293 (IC50 15.8 μmol l-1). It was suggested one of the possible mechanism of substance 2 cytotoxicity via HIF pathway inhibition.
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Danalev D, Borisova D, Yaneva S, Georgieva M, Balacheva A, Dzimbova T, Iliev I, Pajpanova T, Zaharieva Z, Givechev I, Naydenova E. Synthesis, in vitro biological activity, hydrolytic stability and docking of new analogs of BIM-23052 containing halogenated amino acids. Amino Acids 2020; 52:1581-1592. [PMID: 33215308 DOI: 10.1007/s00726-020-02915-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 11/06/2020] [Indexed: 11/25/2022]
Abstract
One of the potent somatostatin analogs, BIM-23052 (DC-23-99) D-Phe-Phe-Phe-D-Trp-Lys-Thr-Phe-Thr-NH2, has established in vitro growth hormone inhibitory activity in nM concentrations. It is also characterized by high affinity to some somatostatin receptors which are largely distributed in the cell membranes of many tumor cells. Herein, we report the synthesis of a series of analogs of BIM-23052 containing halogenated Phe residues using standard solid-phase peptide method Fmoc/OtBu-strategy. The cytotoxic effects of the compounds were tested in vitro against two human tumor cell lines-breast cancer cell line and hepatocellular cancer cell line, as well as on human non-tumorigenic epithelial cell line. Analogs containing fluoro-phenylalanines are cytotoxic in μM range, as the analog containing Phe (2-F) showed better selectivity against human hepatocellular cancer cell line. The presented study also reveals that accumulation of halogenated Phe residues does not increase the cytotoxicity according to tested cell lines. The calculated selective index reveals different mechanisms of antitumor activity of the parent compound BIM-23052 and target halogenated analogs for examined breast tumor cell lines. All peptides tested have high antitumor activity against the HepG2 cell line (IC50 ≈ 100 μM and SI > 5) compared to breast cells. This is probably due to the high permeability of the cell membrane and the higher metabolic activity of hepatocytes. In silico docking studies confirmed that all obtained analogs bind well with the somatostatin receptors with preference to ssrt3 and ssrt5. All target compounds showed high hydrolytic stability at acid and neutral pH, which mimic physiological condition in stomach and human plasma.
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Affiliation(s)
- Dancho Danalev
- Biotechnology Department, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
| | - Desislava Borisova
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
| | - Spaska Yaneva
- Department of Fundamental of Chemical Technology, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
| | - Maya Georgieva
- Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Anelia Balacheva
- Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Tatyana Dzimbova
- Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, Sofia, Bulgaria.,South-West University "Neofit Rilski", Blagoevgrad, Bulgaria
| | - Ivan Iliev
- Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bl. 25, 1113, Sofia, Bulgaria
| | - Tamara Pajpanova
- Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Zdravka Zaharieva
- Biotechnology Department, University of Chemical Technology and Metallurgy, Sofia, Bulgaria.,Testing Center Global Test Ltd, 31 Krushovski vrah Street, Sofia, Bulgaria
| | - Ivan Givechev
- Biotechnology Department, University of Chemical Technology and Metallurgy, Sofia, Bulgaria.,Testing Center Global Test Ltd, 31 Krushovski vrah Street, Sofia, Bulgaria
| | - Emilia Naydenova
- Department of Organic Chemistry, University of Chemical Technology and Metallurgy, Sofia, Bulgaria.
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Xing DY, Chen Y, Zhu J, Liu T. Fabrication of hydrolytically stable magnetic core-shell aminosilane nanocomposite for the adsorption of PFOS and PFOA. Chemosphere 2020; 251:126384. [PMID: 32143082 DOI: 10.1016/j.chemosphere.2020.126384] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 02/25/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
Aminosilane materials, with their low cost and ease of modification, have exhibited great potential for the adsorption of perfluorinated compounds (PFCs) from water. However, this kind of material may be facing two drawbacks during its application: low resistance to hydrolysis and difficulties in separation from the water matrix. This work proposed a strategy of grafting N-(2-aminoethyl) aminopropyltrimethoxysilane (AE-APTMS) on the surface of magnetic γ-Fe2O3 nanoparticles by full utilization of the sorption sites provided by the aminosilane and the magnetism by γ-Fe2O3. The FTIR and XRD results verified the formation of the magnetic AE-APTMS nanocomposite. The core-shell nanocomposite showed a superparamagnetic property and an isoelectric point at pH = 8.2. Particularly, compared to the aminopropyltriethoxysilane (APTES) nanocomposite, the AE-APTMS nanocomposite exhibited improved hydrolytic stability with 60% less loss of the amine groups during the 48 h adsorption process, as the longer alkyl chain hindered the aminosilane detachment. The AE-APTMS nanocomposite exhibited a rapid adsorption with the removal efficiency of 78% for perfluorooctane sulfonate (PFOS) and 65% for perfluorooctanoate (PFOA) due to the electrostatic interaction and hydrophobic interaction. The regeneration and reuse of the magnetic AE-APTMS nanocomposite were conveniently realized with the removal efficiency higher than 70% for both PFOS and PFOA even after 15 adsorption-desorption cycles. The stable magnetic aminosilane nanocomposite with the ease of separation may provide a new strategy to achieve the economical and effective removal of typical PFCs from water.
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Affiliation(s)
- Ding Yu Xing
- Harbin Institute of Technology, Shenzhen; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen, 518055, PR China
| | - Yihua Chen
- Harbin Institute of Technology, Shenzhen; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen, 518055, PR China
| | - Jiaxin Zhu
- Harbin Institute of Technology, Shenzhen; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen, 518055, PR China
| | - Tongzhou Liu
- Harbin Institute of Technology, Shenzhen; Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen, 518055, PR China.
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Song L, Sarikaya R, Ye Q, Misra A, Tamerler C, Spencer P. Multifunctional monomer acts as co-initiator and crosslinker to provide autonomous strengthening with enhanced hydrolytic stability in dental adhesives. Dent Mater 2020; 36:284-95. [PMID: 31806495 DOI: 10.1016/j.dental.2019.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 10/31/2019] [Accepted: 11/15/2019] [Indexed: 12/23/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate a new synthesized multifunctional monomer, aminosilane functionalized methacrylate (ASMA), containing polymerizable methacrylate, tertiary amine, and methoxysilane functionalities in dental adhesive formulations, and to investigate the polymerization kinetics, leachates, thermal and mechanical properties of copolymers. METHODS Adhesive contained HEMA/BisGMA (45/55, w/w) was used as a control, and mixtures based on HEMA/BisGMA/ASMA at the mass ratio of 45/(55-x)/x were used as experimental adhesive. Adhesives were characterized with regard to water miscibility, photo-polymerization behavior (Fourier transform infrared spectroscopy, FTIR), leached co-monomers (high performance liquid chromatography, HPLC), thermal properties (modulated differential scanning calorimeter, MDSC), and mechanical properties (dynamic mechanical analyzer, DMA). Stress relaxation times and the corresponding moduli, obtained from stress relaxation tests, are used in a simulated linear loading case. RESULTS As compared to the control, ASMA-containing adhesives showed higher water miscibility, lower viscosity, improved monomer-to-polymer conversion, significantly greater Tg and rubbery modulus. HPLC results indicated a substantial reduction of leached HEMA (up to 85wt%) and BisGMA (up to 55wt%) in ethanol. The simulation reveals that the ASMA-containing adhesive becomes substantially stiffer than the control. SIGNIFICANCE ASMA monomer plays multiple roles, i.e. it serves as both a co-initiator and crosslinker while also providing autonomous strengthening and enhanced hydrolytic stability in the adhesive formulations. This multifunctional monomer offers significant promise for improving the durability of the adhesive at the composite/tooth interface.
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Papynov EK, Shichalin OO, Mayorov VY, Kuryavyi VG, Kaidalova TA, Teplukhina LV, Portnyagin AS, Slobodyuk AB, Belov AA, Tananaev IG, Avramenko VA, Sergienko VI. SPS technique for ionizing radiation source fabrication based on dense cesium-containing core. J Hazard Mater 2019; 369:25-30. [PMID: 30763796 DOI: 10.1016/j.jhazmat.2019.02.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/22/2019] [Accepted: 02/04/2019] [Indexed: 06/09/2023]
Abstract
The work presents a novel method for fabrication of the high-quality ionizing radiation source (IRS), which is promising to replace unsafe commercial products based on 137CsCl prohibited by IAEA. Spark plasma sintering (SPS) technique has been applied to produce dense ceramic and glass-ceramic matrixes from Cs-containing (˜13.5 wt.%) zeolite yielding in non-dispersible cores sealed in the container of radiation-resistant steel (J93503, US standard). One-stage SPS regimes to provide high-quality product have been optimized: sintering temperature <1000 °C, heating and holging duration 13 and 5 min, respectively, pressure 24.5 MPa. XRD, SEM, EDX, BET, XFS and solid-state MAS NMR 133Cs methods prove exceptional physico-chemical and mechanical characteristics of the obtained materials, namely: density 99.8% from theoretical, compressive strength ˜477 MPa, leaching rate 10-4-10-6 g cm-2 day-1. Results of the investigation can be promising for fabrication of the IRS cores on a large scale as done for similar Russian products RSL, IGI-C, M37C, GID-C.
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Affiliation(s)
- E K Papynov
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia; Far Eastern Federal University, 8, Sukhanova St., Vladivostok, 690091, Russia
| | - O O Shichalin
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia; Far Eastern Federal University, 8, Sukhanova St., Vladivostok, 690091, Russia
| | - V Yu Mayorov
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia
| | - V G Kuryavyi
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia
| | - T A Kaidalova
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia
| | - L V Teplukhina
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia
| | - A S Portnyagin
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia; Far Eastern Federal University, 8, Sukhanova St., Vladivostok, 690091, Russia.
| | - A B Slobodyuk
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia
| | - A A Belov
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia; Far Eastern Federal University, 8, Sukhanova St., Vladivostok, 690091, Russia
| | - I G Tananaev
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia; Far Eastern Federal University, 8, Sukhanova St., Vladivostok, 690091, Russia; A.N. Frumkin Institute of Physical Chemistry and Electrochemistry of Russian Academy of Sciences, 1, Leninsky prosp., Moscow, 199071, Russia
| | - V A Avramenko
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia
| | - V I Sergienko
- Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, 159, Prosp. 100-letiya Vladivostoka, Vladivostok, 690022, Russia
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Xu P, Trinh MN, Kováč P. Conjugation of carbohydrates to proteins using di(triethylene glycol monomethyl ether) squaric acid ester revisited. Carbohydr Res 2018; 456:24-29. [PMID: 29247910 DOI: 10.1016/j.carres.2017.10.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 10/19/2017] [Accepted: 10/20/2017] [Indexed: 01/21/2023]
Abstract
Properties of di(triethylene glycol monomethyl ether) squarate relevant to conjugation of carbohydrates to proteins have been reinvestigated and compared with those of dimethyl squarate. It is concluded that the commercially available, crystalline dimethyl squarate remains the most convenient and efficient reagent for conjugation of amine-containing carbohydrates to proteins by a two-step or one-pot conjugation protocol.
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Affiliation(s)
- Peng Xu
- NIDDK, LBC, National Institutes of Health, Bethesda, MD 20892-0815, USA
| | - Michael N Trinh
- NIDDK, LBC, National Institutes of Health, Bethesda, MD 20892-0815, USA
| | - Pavol Kováč
- NIDDK, LBC, National Institutes of Health, Bethesda, MD 20892-0815, USA.
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Navarro FH, Gómez JE, Espinal JH, Sandoval JE. Neutral hydrophilic coatings for capillary electrophoresis prepared by controlled radical polymerization. Anal Chim Acta 2016; 948:104-112. [PMID: 27871605 DOI: 10.1016/j.aca.2016.10.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 10/15/2016] [Accepted: 10/16/2016] [Indexed: 11/29/2022]
Abstract
In the present study, porous silica particles as well as impervious fused-silica wafers and capillary tubes were modified with hydrophilic polymers (hydroxylated polyacrylamides and polyacrylates), using a surface-confined grafting procedure based on atom transfer radical polymerization (ATRP) which was also surface-initiated from α-bromoisobutyryl groups. Initiator immobilization was achieved by hydrosilylation of allyl alcohol on hydride silica followed by esterification of the resulting propanol-bonded surface with α-bromoisobutyryl bromide. Elemental analysis, IR and NMR spectroscopies on silica micro-particles, atomic force microscopy, ellipsometry and profilometry on fused-silica wafers, as well as CE on fused-silica tubes were used to characterize the chemically modified silica substrate at different stages. We studied the effect of monomer concentration as well as cross-linker on the ability of the polymer film to reduce electroosmosis and to prevent protein adsorption (i. e., its non-fouling capabilities) and found that the former was rather insensitive to both parameters. Surface deactivation towards adsorption was somewhat more susceptible to monomer concentration and appeared also to be favored by a low concentration of the cross-linker. The results show that hydrophilic polyacrylamide and polyacrylate coatings of controlled thickness can be prepared by ATRP under very mild polymerization conditions (aqueous solvent, room temperature and short reaction times) and that the coated capillary tubes exhibit high efficiencies for protein separations (0.3-0.6 million theoretical plates per meter) as well as long-term hydrolytic stability under the inherently harsh conditions of capillary isoelectric focusing. Additionally, there was no adsorption of lysozyme on the coated surface as indicated by a complete recovery of the basic enzyme. Furthermore, since polymerization is confined to the inner capillary surface, simple precautions (e.g., solution filtration) during the surface modification process are sufficient to prevent capillary clogging.
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Affiliation(s)
| | - Jorge E Gómez
- Department of Chemistry, Universidad del Valle, Cali, Colombia
| | - José H Espinal
- Department of Chemistry, Universidad del Valle, Cali, Colombia
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Abstract
AIMS Resin infiltration is an emerging technique for management of noncavitated lesions. This study evaluated the in vitro hydrolytic and color stability of the ICON® resin infiltration system (IC) in 42 extracted human teeth. MATERIALS AND METHODS ICON® resin infiltration system was compared with dental adhesive (DA) and dental sealant (DS). The products were applied according to manufacturer's instructions. The baseline weight and color of the samples were recorded. Color was recorded by spectoral colorimeter. The samples were subjected to four experimental conditions: (1) group 1: Stored in lactic acid solution (pH 4.9) for 24 hours; (2) group 2: Thermocycled for 100 cycles (temperatures: 5°C, 55°C, and dwell time of 15 seconds); (3) group 3: Stored in 0.1 N sodium hydroxide solution (pH 12.48) for 14 days at 60°C; (4) group 4: Stored in phosphate-buffered saline solution (pH 7.2) at 37°C for 4 months. The weight and color were recorded again after removal of the samples from the experimental conditions. Two-factor analysis of variance models and Tukey's Honestly Significant Difference were performed to assess statistical differences among the groups. Scanning electron microscopy imaging was performed for samples from groups 1, 3, and 4. RESULTS All the samples showed loss of material and change in color. In the demineralizing solution, IC showed significantly greater weight loss (p = 0.032) and color change (p = 0.038) compared with DA. Dental Sealant showed significantly greater weight loss than IC (p = 0.027) after thermocycling. Teeth in group 3 exhibited the greatest weight loss (p < 0.001). Teeth in group 2 exhibited the greatest color change (p < 0.001). CONCLUSION All tested materials showed loss of retention and color change in the experimental conditions. Infiltration system exhibited greatest weight loss and color change in demineralizing solution. Dental sealant exhibited greatest weight loss upon thermocycling. CLINICAL SIGNIFICANCE Clinicians should be cautious about the limitations of retention and color stability when considering resin infiltration for incipient lesions.
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Affiliation(s)
- Priyanshi Ritwik
- Associate Pofessor, Department of Pediatric Dentistry, LSUHSC School of Dentistry, New Orleans, Los Angeles, USA, Phone: +5043528038, e-mail: ,
| | - Christopher M Jones
- Department of Pediatric Dentistry, LSUHSC School of Dentistry, New Orleans, Los Angeles, USA
| | - Yuwei Fan
- Department of Comprehensive Dentistry, LSUHSC School of Dentistry, New Orleans, Los Angeles, USA
| | - Nikhil K Sarkar
- Department of Comprehensive Dentistry, LSUHSC School of Dentistry, New Orleans, Los Angeles, USA
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Maszkowska J, Stolte S, Kumirska J, Łukaszewicz P, Mioduszewska K, Puckowski A, Caban M, Wagil M, Stepnowski P, Białk-Bielińska A. Beta-blockers in the environment: part I. Mobility and hydrolysis study. Sci Total Environ 2014; 493:1112-21. [PMID: 25005235 DOI: 10.1016/j.scitotenv.2014.06.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/09/2014] [Accepted: 06/09/2014] [Indexed: 05/24/2023]
Abstract
Beta-blockers (BB) are one of the most widely used pharmaceuticals whose presence in different environmental compartments has already been proven in concentrations of even up to a few μg L(-1). However, our knowledge of their fate in the environment is still scarce. To obtain a better understanding on the environmental behavior of three selected BB comprehensive laboratory experiments assessing their mobility and hydrolytic stability has been conducted. Propranolol, metoprolol and nadolol--the most commonly consumed and detected in environmental samples--were selected as representatives of this group of pharmaceuticals. The objectives of our research were: (i) evaluation of the sorption potential and an explanation of the sorption mechanisms of these compounds onto soil and clay mineral (kaolinite); and (ii) investigation of the hydrolytic stability of these BB according to OECD 111. This comprehensive study supports the Environmental Risk Assessment of these pharmaceuticals.
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Affiliation(s)
- Joanna Maszkowska
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Stefan Stolte
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland; UFT - Center for Environmental Research and Sustainable Technology, University of Bremen, Leobener Straße, D-28359 Bremen, Germany
| | - Jolanta Kumirska
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
| | - Paulina Łukaszewicz
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Katarzyna Mioduszewska
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Alan Puckowski
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Magda Caban
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Marta Wagil
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Piotr Stepnowski
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Anna Białk-Bielińska
- Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland; UFT - Center for Environmental Research and Sustainable Technology, University of Bremen, Leobener Straße, D-28359 Bremen, Germany
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