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Desai V, Kowshik M. Synthesis and characterization of fumaric acid functionalized AgCl/titania nanocomposite with enhanced antibacterial activity. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2013; 13:2826-2834. [PMID: 23763167 DOI: 10.1166/jnn.2013.7370] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Silver based antimicrobial agents with TiO2 as a host support (AgCl/TiO2) are increasingly being evaluated for disinfection and therapeutic applications. In this work TiO2 supported silver chloride nanocomposites were synthesized and functionalized with fumaric acid. X-ray diffraction results showed that the TiO2 was in anatase phase and AgCI was in the cubic chalcoargyrite phase. The functionalization was confirmed by FTIR analysis. The fumaric acid functionalized AgCl/TiO2 (Fu-AgCl/TiO2) showed uniform particle size distribution in the range of 4-5 nm. The intensity size distribution of Fu-AgCl/TiO2 nanocomposite by DLS showed an average particle diameter of -290 nm with a polydispersity index (P. I.) of 0.47. Further, a high BET surface area of -320.7 m2/g was observed for Fu-AgCl/TiO2 with an average pore size distribution of 3.8 nm. The antimicrobial activity of Fu-AgCl/TiO2 and AgCl/TiO2 was evaluated by determining the MIC and MBC values, and it was observed that Fu-AgCl/TiO2 exhibited better antimicrobial activity as compared to the unfunctionalized nanocomposite. The antimicrobial activity of Fu-AgCl/TiO2 is mainly attributed to its superior physicochemical properties coupled with the synergistic action of both fumaric acid and silver ions. The changes in the cytoplasmic membrane of the cells due to the formation of intracellular ROS were observed by SEM imaging.
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Bongio M, van den Beucken JJJ, Nejadnik MR, Tahmasebi Birgani Z, Habibovic P, Kinard LA, Kasper FK, Mikos AG, Leeuwenburgh SCG, Jansen JA. Subcutaneous tissue response and osteogenic performance of calcium phosphate nanoparticle-enriched hydrogels in the tibial medullary cavity of guinea pigs. Acta Biomater 2013; 9:5464-74. [PMID: 23107797 DOI: 10.1016/j.actbio.2012.10.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 10/12/2012] [Accepted: 10/19/2012] [Indexed: 01/24/2023]
Abstract
In the current study, oligo(poly(ethylene glycol) fumarate) (OPF)-based hydrogels were tested for the first time as injectable bone substitute materials. The primary feature of the material design was the incorporation of calcium phosphate (CaP) nanoparticles within the polymeric matrix in order to compare the soft tissue response and bone-forming capacity of plain OPF hydrogels with CaP-enriched OPF hydrogel composites. To that end, pre-set scaffolds were implanted subcutaneously, whereas flowable polymeric precursor solutions were injected in a tibial ablation model in guinea pigs. After 8 weeks of implantation, histological and histomorphometrical evaluation of the subcutaneous scaffolds confirmed the biocompatibility of both types of hydrogels. Nevertheless, OPF hydrogels presented a loose structure, massive cellular infiltration and extensive material degradation compared to OPF-CaP hydrogels that were more compact. Microcomputed tomography and histological and histomorphometrical analyses showed comparable amounts of new trabecular bone in all tibias and some material remnants in the medial and distal regions. Particularly, highly calcified areas were observed in the distal region of OPF-CaP-treated tibias, which indicate a heterogeneous distribution of the mineral phase throughout the hydrogel matrix. This phenomenon can be attributed to either hindered gelation under highly perfused in vivo conditions or a faster degradation rate of the polymeric hydrogel matrix compared to the nanostructured mineral phase, resulting in loss of entrapment of the CaP nanoparticles and subsequent sedimentation.
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Dadsetan M, Taylor KE, Yong C, Bajzer Ž, Lu L, Yaszemski MJ. Controlled release of doxorubicin from pH-responsive microgels. Acta Biomater 2013; 9:5438-46. [PMID: 23022545 PMCID: PMC3970914 DOI: 10.1016/j.actbio.2012.09.019] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/13/2012] [Accepted: 09/18/2012] [Indexed: 10/27/2022]
Abstract
Stimuli-responsive hydrogels have enormous potential in drug delivery applications. They can be used for site-specific drug delivery due to environmental variables in the body such as pH and temperature. In this study, we have developed pH-responsive microgels for the delivery of doxorubicin (DOX) in order to optimize its anti-tumor activity while minimizing its systemic toxicity. We used a copolymer of oligo(polyethylene glycol) fumarate (OPF) and sodium methacrylate (SMA) to fabricate the pH-responsive microgels. We demonstrated that the microgels were negatively charged, and the amounts of charge on the microgels were correlated with the SMA concentration in their formulation. The resulting microgels exhibited sensitivity to the pH and ionic strength of the surrounding environment. We demonstrated that DOX was efficiently loaded into the microgels and released in a controlled fashion via an ion-exchange mechanism. Our data revealed that the DOX release was influenced by the pH and ionic strength of the solution. Moreover, we designed a phenomenological mathematical model, based on a stretched exponential function, to quantitatively analyze the cumulative release of DOX. We found a linear correlation between the maximum release of DOX calculated from the model and the SMA concentration in the microgel formulation. The anti-tumor activity of the released DOX was assessed using a human chordoma cell line. Our data revealed that OPF-SMA microgels prolonged the cell killing effect of DOX.
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Jiang YR, Zhang ZH, Jia XB. [Preparation and application on compound excipient of sodium stearyl fumarate and plasdone S-630]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 2013; 48:125-130. [PMID: 23600153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The compound excipient containing sodium stearyl fumarate and plasdone S-630 was prepared by applying spray drying method. The basic physical properties of compound excipient were studied by solubility test, scanning electron microscope, differential scanning calorimeter, X-ray diffraction and Fourier transform infra-red spectroscopy. The effect of compound excipient on moisture absorption and ferulic acid in vitro dissolution of spray drying power of angelica were investigated. The results showed that the chemical constituents of compound excipient did not change before and after spray drying. The water soluble compound excipient can improve significantly moisture absorption and has application prospect.
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Dolińska B, Ostróżka-Cieślik A, Caban A, Rimantas K, Leszczyńska L, Ryszka F. Influence of trace elements on stabilization of aqueous solutions of ascorbic acid. Biol Trace Elem Res 2012; 150:509-12. [PMID: 23099563 PMCID: PMC3510389 DOI: 10.1007/s12011-012-9524-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 10/05/2012] [Indexed: 01/31/2023]
Abstract
Together with vitamin C, zinc, selenium, manganese, and magnesium play a vital role in the preservation of organs scheduled for transplantation. In the present study, it is shown that addition of 1 mg/l of these elements influences the stability of 0.3 mM ascorbic acid solutions. The solution's stability was estimated using an accelerated stability test. The concentration of vitamin C was measured using a validated spectrophotometric method, which uses the reduction of 2,6-dichlorophenoloindophenol by ascorbic acid. Elevated temperatures, the factor accelerating substances' decomposition reaction rate, were used in the tests. The research was conducted at two temperatures at intervals of 10 °C: 80 ± 0.1 and 90 ± 0.1 °C. It was stated that the studied substances' decomposition occurred in accordance with the equation for first-order reactions. The function of the logarithmic concentration (log%C) over time was revealed to be rectilinear. This dependence was used to determine the kinetics of decomposition reaction rate parameters. The stabilization of vitamin C solutions was measured as the time in which 10 % of the substance decomposed at 20 and 0 °C. Addition of Se(IV) or Mg(II) ions significantly increase the stability of ascorbic acid solution (∼34 and ∼16 %, respectively), but Zn(II) causes a significant decrease in stability by ∼23 %. Addition of Mn(II) has no significant influence on vitamin C stability.
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Zakikhani M, Bazile M, Hashemi S, Javeshghani S, Avizonis D, Pierre JS, Pollak MN. Alterations in cellular energy metabolism associated with the antiproliferative effects of the ATM inhibitor KU-55933 and with metformin. PLoS One 2012. [PMID: 23185347 PMCID: PMC3504012 DOI: 10.1371/journal.pone.0049513] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
KU-55933 is a specific inhibitor of the kinase activity of the protein encoded by Ataxia telangiectasia mutated (ATM), an important tumor suppressor gene with key roles in DNA repair. Unexpectedly for an inhibitor of a tumor suppressor gene, KU-55933 reduces proliferation. In view of prior preliminary evidence suggesting defective mitochondrial function in cells of patients with Ataxia Telangiectasia (AT), we examined energy metabolism of cells treated with KU-55933. The compound increased AMPK activation, glucose uptake and lactate production while reducing mitochondrial membrane potential and coupled respiration. The stimulation of glycolysis by KU-55933 did not fully compensate for the reduction in mitochondrial functions, leading to decreased cellular ATP levels and energy stress. These actions are similar to those previously described for the biguanide metformin, a partial inhibitor of respiratory complex I. Both compounds decreased mitochondrial coupled respiration and reduced cellular concentrations of fumarate, malate, citrate, and alpha-ketogluterate. Succinate levels were increased by KU-55933 levels and decreased by metformin, indicating that the effects of ATM inhibition and metformin are not identical. These observations suggest a role for ATM in mitochondrial function and show that both KU-55933 and metformin perturb the TCA cycle as well as oxidative phosphorylation.
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Antony Joseph A, Ramachandra Raja C. Studies on growth and spectral characterization of diglycine fumarate monohydrate single crystals. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 97:1120-1124. [PMID: 22935641 DOI: 10.1016/j.saa.2012.07.134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 07/19/2012] [Accepted: 07/26/2012] [Indexed: 06/01/2023]
Abstract
Single crystals of organic optical material, diglycine fumarate monohydrate (DGFM) has been synthesized and grown from solution by slow evaporation solution growth method. Purity of synthesized materials was increased by continuous recrystallization. The lattice parameters of the grown crystals are observed by X-ray diffraction method and the crystal system of grown crystal is identified as monoclinic. The optical transparency range has been investigated by UV-Vis-NIR spectroscopy method in the range between 190 and 1,100 nm. The presence of different modes of vibrations is analyzed using FT-IR technique. The carbon and hydrogen atmosphere in molecular structure of DGFM is investigated using FT-NMR method. The thermogravimetrrc analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC) analysis shows that the grown crystal has very good thermal stability up to 263°C. The Kurtz-Perry powder SHG test has done for grown crystals.
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Xiong JF, Xu H, Yan N, Zhang YM. [Leaves of Platanus orientalis as the carbon source for denitrification]. HUAN JING KE XUE= HUANJING KEXUE 2012; 33:4057-4061. [PMID: 23323446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Leaching solution from Platanus orientalis fallen leaves was used as the carbon source for denitrification, and organic acid releasing regularity and influencing factors during the dipping process were discussed. The main organic acid was fumarate, and others were citric acid, oxalic acid and malic acid according to the analysis by HPLC. The average nitrate removal rate was 2.19 mg x h(-1), when the leaching solution was used as the carbon source during denitrification, while the rates were 2.29, 2.26 and 1.87 mg x h(-1) respectively with methanol, acetic acid and glucose as the carbon source. The rate with the leaching solution was slightly lower than those with methanol and acetic acid, but higher than that with glucose. The experimental results indicated that 7.5 mg equivalent of COD from the leaching solution of Platanus orientalis fallen leaves were met for 1 mg nitrate reduction and there was no nitrite accumulation during the denitrification.
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Vehring R, Lechuga-Ballesteros D, Joshi V, Noga B, Dwivedi SK. Cosuspensions of microcrystals and engineered microparticles for uniform and efficient delivery of respiratory therapeutics from pressurized metered dose inhalers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15015-15023. [PMID: 22985189 DOI: 10.1021/la302281n] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Engineered porous phospholipid microparticles with aerodynamic diameters in the respirable range of 1-2 μm were cosuspended in 1,1,1,2-tetrafluoroethane, a propellant, with microcrystals of glycopyrrolate, formoterol fumarate dihydrate, or Mometasone furoate-three drugs with different solubilities in the propellant, and different physical, chemical, and pharmacological attributes. The drug microcrystals were added individually, in pairs, or all three together to prepare different cosuspensions, contained in a pressurized metered dose inhaler (pMDI). The drug microcrystals irreversibly associated with the porous particles, and the resultant cosuspensions possessed greatly improved suspension stability compared with suspensions of drug microcrystals alone. In general, all cosuspensions showed efficient dose delivery of the drugs, with fine particle fractions of more than 60% for a wide range of doses, including those as low as 300 ng per inhaler actuation. In the cosuspension pMDIs, comparable fine particle fractions were delivered for all tested drugs, whether or not they were emitted from an inhaler containing one, two, or three drugs. We demonstrate that the cosuspension approach solves at least three long-standing problems in the clinical development of pMDI-based products: (1) dose and drug dependent delivery efficiency, (2) inability to formulate dose strengths below 1 μg to fully explore drug efficacy and safety, and (3) combination suspensions delivering a different fine particle fraction than individual drug suspensions.
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Fong EL, Watson BM, Kasper FK, Mikos AG. Building bridges: leveraging interdisciplinary collaborations in the development of biomaterials to meet clinical needs. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:4995-5013. [PMID: 22821772 PMCID: PMC3706713 DOI: 10.1002/adma.201201762] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 06/28/2012] [Indexed: 05/22/2023]
Abstract
Our laboratory at Rice University has forged numerous collaborations with clinicians and basic scientists over the years to advance the development of novel biomaterials and the modification of existing materials to meet clinical needs. This review highlights collaborative advances in biomaterials research from our laboratory in the areas of scaffold development, drug delivery, and gene therapy, especially as related to applications in bone and cartilage tissue engineering.
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Beasley KK, Nanny MA. Potential energy surface for anaerobic oxidation of methane via fumarate addition. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:8244-8252. [PMID: 22703611 DOI: 10.1021/es3009503] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Microbially mediated anaerobic oxidation of methane (AOM) is an important sink in the global methane cycle, but the mechanism and microorganisms responsible for this oxidation are not fully known. Using quantum chemical calculations, fumarate addition to methane was examined to determine if it could be an energetically feasible mechanism for AOM. A potential energy surface (PES) for the initial reaction was created and the results suggest the reaction is exothermic, with a calculated overall energy change between -9.8 and -11.2 kcal/mol. The addition of methane to fumarate is calculated to be the highest point on the surface, 25.0-25.3 kcal/mol above the reactants. Of the three possible molecular configurations of fumarate considered, the one that presents the least steric obstacles to the addition reaction with methane yields the greatest energy gain. While 11.2 kcal/mol may support growth under energy limited conditions it is unknown if enzymes can mediate an energetic barrier of 25 kcal/mol. These calculated energies provide values for what could be one of the least reactive substrates to undergo fumarate addition, making methane a model substrate in defining the limits of energy barriers and minimal energy requirements for growth in reactions activated by glycyl radical-containing enzymes.
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Jing T, Feng J, Zuo Y, Ran B, Liu J, He G. Exploring the substructural space of indole-3-carboxamide derivatives binding to renin: a novel active-site spatial partitioning approach. J Mol Model 2012; 18:4417-26. [PMID: 22588582 DOI: 10.1007/s00894-012-1434-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 04/16/2012] [Indexed: 12/11/2022]
Abstract
Renin has recently attracted much attention in the antihypertensive community, since this enzyme starts the angiotensin-converting cascade and forms the rate-limiting step in this cascade. In the present study, we describe a new method called active-site spatial partitioning (ASSP) for quantitatively characterizing the nonbonding interaction profile between renin and the substructures of indole-3-carboxamide derivatives-a novel class of achiral renin inhibitors that exhibit both high affinity and strong specificity for renin, thus blocking its active state-on the basis of structural models of protein-ligand complexes. It is shown that the ASSP-derived potential parameters are highly correlated with the experimentally measured activities of indole-3-carboxamides; the statistical models linking the parameters and activities using a sophisticated partial least squares regression technique show much promise as an effective and powerful tool for generalizing and predicting the pharmaceutical potencies and the physicochemical properties of other modified derivatives. Furthermore, by visually examining substructure-color plots generated by the ASSP procedure, it is found that the relative importance of nonbonding contributions to the recognition and binding of a ligand by renin is as follows: steric < hydrophobic < electrostatic. The polar and charged moieties that float on the surface of the ligand molecule play a critical role in conferring electrostatic stability and specificity to renin-ligand complexes, whereas the aromatic rings embedded in the core region of the ligand are the main source of hydrophobic and steric potentials that lead to substantial stabilization of the complex architecture.
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Gupta VP, Tandon P. Conformational and vibrational studies of isomeric hydrogen cyanide tetramers by quantum chemical methods. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 89:55-66. [PMID: 22245939 DOI: 10.1016/j.saa.2011.12.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 11/18/2011] [Accepted: 12/15/2011] [Indexed: 05/31/2023]
Abstract
The results of structural studies and detailed harmonic and anharmonic vibrational analysis on two hydrogen cyanide (HCN) tetramers diaminomaleonitrile (DAMN) and diaminofumaronitrile (DAFN), which are important molecules for understanding the chemistry of interstellar space and nitrile rich environments, are being reported on the basis of density functional theory using second-order perturbation theory. Both the molecules are found to have C1 symmetry. While all the heavy atoms of DAMN lie in the same plane (maximum deviation 6°), the two nitrogen atoms in DAFN are out of plane by about 15°. The two amino groups are tetrahedral and do not have significant bond angle anisotropy. Detailed conformational studies are reported on the two molecules and their possible rotational isomers are identified. Complete vibrational analysis based on harmonic and anharmonic frequencies, intensity of infrared and activity of Raman bands and potential energy distribution over the internal coordinates has been provided for the two molecules. Affect of hydrogen bonding on molecular geometry and frequencies of the NH stretch modes has been studied by calculations on the dimers of the two molecules. A close agreement has been observed between the experimental and calculated frequencies. Vibrational-rotational constants such as rotational constants in the ground vibrational state (A0, B0, C0) and the effective rotational constants (Ae, Be and Ce), including terms due to quartic centrifugal distortion constants, rotation-vibration coupling constants, Wilson and Nielsen's centrifugal distortion constants have been calculated using B3LYP and B97-1 functionals and 6-31G**, 6-311+G** and TZVP basis sets.
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Malík I, Mitterová L, Andriamainty F, Mokrý P, Lukác M, Csöllei J, Galisinová J, Karlovská J. [Analytical profile of mono[{3-[4-(2-ethoxyethoxy)-benzoyloxy]-2-hydroxypropyl}-tert-butylammonium] fumarate]. CESKA A SLOVENSKA FARMACIE : CASOPIS CESKE FARMACEUTICKE SPOLECNOSTI A SLOVENSKE FARMACEUTICKE SPOLECNOSTI 2012; 61:44-52. [PMID: 22536653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The present paper aims at a complex spectral and physicochemical evaluation of mono[{3-[4-(2-eth-oxyethoxy)-benzoyloxy]-2-hydroxypropyl)-tert-butyl-ammonium] fumarate, the potential ultra-short acting blocker of beta1-adrenergic receptors. The identity of the evaluated compound (labelled as UPB-2) was confirmed by 1H-, 13C-NMR and IR spectral data as well. The estimated physicochemical parameters included melting point data, solubility in various media, purity checking (adsorption thin-layer chromatography), surface activity determination (non-direct Traube stalagmometric method), acidobasic characteristics (pKa value determination by alkalimetric titration), log epsilon values estimation (spectrophotometrically in UV/VIS region) and a study of the influence of acidic and alkaline media towards the stability of UPB-2. Other experimentally estimated values were lipohydrophilic descriptors using RP-HPLC (log k') and the log PexpS in various lipohydrophilic media by the shake flask method. Based on the log Pexp readouts, the ability to permeate across the brain-blood barrier was predicted. For the content determination of UBP-2 the RP-HPLC (reversed-phase HPLC), the method of an internal standard and UV/VIS spectrophotometry at the wavelength of 260 nm (aqueous medium) and at 258 nm (methanolic medium) was applied.
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Erythropel HC, Maric M, Cooper DG. Designing green plasticizers: influence of molecular geometry on biodegradation and plasticization properties. CHEMOSPHERE 2012; 86:759-766. [PMID: 22113055 DOI: 10.1016/j.chemosphere.2011.10.054] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 10/23/2011] [Accepted: 10/24/2011] [Indexed: 05/31/2023]
Abstract
The plasticizer di (2-ethylhexyl) phthalate (DEHP) and its metabolites are considered ubiquitous contaminants, which have a range of implications on the environment and human health. This work considered several alternative compounds with structural features similar to DEHP. This added to the understanding of why DEHP is so poorly biodegraded once it enters the environment. These alternative compounds were based on 2-ethylhexyl diesters of maleic acid (cis-isomer), fumaric acid (trans-isomer) and succinic acid (saturated analogue). The rates of biodegradation by the common soil bacterium Rhodococcus rhodocrous were shown to be dependent on the structure of the central unit derived from the diacid used to make the ester. The diacid components of DEHP and the maleate both had a cis orientation and they were the two that were slow to biodegrade. Plasticizing properties were also compared and, because the ester of the saturated succinic acid was degraded quickly and also had good plasticizing properties, it was concluded that the succinic esters of straight chain alcohols would make the best green plasticizers. The maleate ester had excellent plasticizing properties but this is mitigated by a significant resistance to biodegradation.
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Zhang Y, Huang B, Zhao Z, Zhou Y. [Study on the chemical constituents from the ethyl acetate extracts of Cremastra appendiculata]. ZHONG YAO CAI = ZHONGYAOCAI = JOURNAL OF CHINESE MEDICINAL MATERIALS 2011; 34:1882-1883. [PMID: 22500423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To study the chemical constituents from the ethyl acetate extracts of Cremastra appendiculata. METHODS The compounds from the ethyl acetate extracts were isolated by the silica gel column and Sephadex LH-20 column chromatography, their structures were elucidated by the spectral analysis and chemical evidence. RESULTS Seven componds were separated and identified as fumaric acid (1), dimethylhexyl phthalate (2), L-pyroglutamic acid (3), 2-furoic acid (4), vanillic acid (5), p-coumaric acid (6), protocatechuic acid (7). CONCLUSIONS Compounds 1 to 6 are obtained from this plant for the first time.
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Lee Y, Park KH, Seong MH, Kyong JB, Kevill DN. Correlation of the rates of solvolysis of i-butyl fluoroformate and a consideration of leaving-group effects. Int J Mol Sci 2011; 12:7806-17. [PMID: 22174633 PMCID: PMC3233439 DOI: 10.3390/ijms12117806] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 10/21/2011] [Accepted: 10/31/2011] [Indexed: 11/17/2022] Open
Abstract
The specific rates of solvolysis of isobutyl fluoroformate (1) have been measured at 40.0 °C in 22 pure and binary solvents. These results correlated well with the extended Grunwald-Winstein (G-W) equation, which incorporated the N(T) solvent nucleophilicity scale and the Y(Cl) solvent ionizing power scale. The sensitivities (l and m-values) to changes in solvent nucleophilicity and solvent ionizing power, and the k(F)/k(Cl) values are very similar to those observed previously for solvolyses of n-octyl fluoroformate, consistent with the additional step of an addition-elimination pathway being rate-determining. The solvent deuterium isotope effect value (k(MeOH)/k(MeOD)) for methanolysis of 1 was determined, and for solvolyses in ethanol, methanol, 80% ethanol, and 70% TFE, the values of the enthalpy and the entropy of activation for the solvolysis of 1 were also determined. The results are compared with those reported earlier for isobutyl chloroformate (2) and other alkyl haloformate esters and mechanistic conclusions are drawn.
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Moglia RS, Holm JL, Sears NA, Wilson CJ, Harrison DM, Cosgriff-Hernandez E. Injectable polyHIPEs as high-porosity bone grafts. Biomacromolecules 2011; 12:3621-8. [PMID: 21861465 PMCID: PMC3190649 DOI: 10.1021/bm2008839] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polymerization of high internal phase emulsions (polyHIPEs) is a relatively new method for the production of high-porosity scaffolds. The tunable architecture of these polyHIPE foams makes them attractive candidates for tissue engineered bone grafts. Previously studied polyHIPE systems require either toxic diluents or high cure temperatures which prohibit their use as an injectable bone graft. In contrast, we have developed an injectable polyHIPE that cures at physiological temperatures to a rigid, high-porosity foam. First, a biodegradable macromer, propylene fumarate dimethacrylate (PFDMA), was synthesized that has appropriate viscosity and hydrophobicity for emulsification. The process of surfactant selection is detailed with particular focus on the key structural features of both polymer (logP values, hydrogen bond acceptor sites) and surfactant (HLB values, hydrogen bond donor sites) that enable stable HIPE formation. Incubation of HIPEs at 37 °C was used to initiate radical cross-linking of the unsaturated double bond of the methacrylate groups to polymerize the continuous phase and lock in the emulsion geometry. The resulting polyHIPEs exhibited ~75% porosity, pore sizes ranging from 4 to 29 μm, and an average compressive modulus and strength of 33 and 5 MPa, respectively. These findings highlight the great potential of these scaffolds as injectable, tissue engineered bone grafts.
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Choi J, Kim K, Kim T, Liu G, Bar-Shir A, Hyeon T, McMahon MT, Bulte JWM, Fisher JP, Gilad AA. Multimodal imaging of sustained drug release from 3-D poly(propylene fumarate) (PPF) scaffolds. J Control Release 2011; 156:239-45. [PMID: 21763735 DOI: 10.1016/j.jconrel.2011.06.035] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 06/07/2011] [Accepted: 06/24/2011] [Indexed: 12/30/2022]
Abstract
The potential of poly(propylene fumarate) (PPF) scaffolds as drug carriers was investigated and the kinetics of the drug release quantified using magnetic resonance imaging (MRI) and optical imaging. Three different MR contrast agents were used for coating PPF scaffolds. Initially, iron oxide (IONP) or manganese oxide nanoparticles (MONP) carrying the anti-cancer drug doxorubicin were absorbed or mixed with the scaffold and their release into solution at physiological conditions was measured with MRI and optical imaging. A slow (hours to days) and functional release of the drug molecules into the surrounding solution was observed. In order to examine the release properties of proteins and polypeptides, protamine sulfate, a chemical exchange saturation transfer (CEST) MR contrast agent, was attached to the scaffold. Protamine sulfate showed a steady release rate for the first 24h. Due to its biocompatibility, versatile drug-loading capability and constant release rate, the porous PPF scaffold has potential in various biomedical applications, including MR-guided implantation of drug-dispensing materials, development of drug carrying vehicles, and drug delivery for tumor treatment.
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70
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In brief: Another three-drug combination for hypertension. THE MEDICAL LETTER ON DRUGS AND THERAPEUTICS 2011; 53:28. [PMID: 21464804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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71
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Amiri H, Mahmoudi M, Lascialfari A. Superparamagnetic colloidal nanocrystal clusters coated with polyethylene glycol fumarate: a possible novel theranostic agent. NANOSCALE 2011; 3:1022-1030. [PMID: 21152576 DOI: 10.1039/c0nr00603c] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report cell endocytosis, drug release, NMR relaxometry and in vitro MRI studies on a novel class of superparamagnetic colloidal nanocrystal clusters (CNCs) with various biocompatible coatings. It is shown that the transverse relaxivity r2, the parameter representing the MRI efficiency in negative contrast agents, for the PVA-coated, PEGF-coated, and crosslinked PEGF-coated CNCs, is high enough to contrast suitably the magnetic resonance images. The same samples have shown a good ability also in drug releasing (particularly the crosslinked PEGF-coated compound), thus finally allowing us to propose this class of compounds for future applications in theranostics.
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72
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Giménez-Arnau A. Dimethyl fumarate: a human health hazard. Dermatitis 2011; 22:47-49. [PMID: 21291643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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73
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Aboutorabi L, Morsali A. Sonochemical syntheses and characterization of nano-structured three-dimensional lead(II) coordination polymer constructed of fumaric acid. ULTRASONICS SONOCHEMISTRY 2011; 18:407-411. [PMID: 20708955 DOI: 10.1016/j.ultsonch.2010.07.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2010] [Revised: 07/13/2010] [Accepted: 07/19/2010] [Indexed: 05/29/2023]
Abstract
Nano-structured three-dimensional lead(II) coordination polymer, [Pb(μ(6)-Fum)](n) (1); {Fum=Fumarate}, has been synthesized by sonochemical method and characterized by scanning electron microscopy, X-ray powder diffraction, elemental analyses and IR spectroscopy. Solvent effects on size and morphology of nano-structured compound 1 have been studied. Calcination of the nano-sized compound 1 at 600°C under air atmosphere yields PbO nanoparticles. The thermal stability of compound 1 both its bulk and nano-size has been studied by thermal gravimetric (TG) and differential thermal (DTA) analyses and compared each other.
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74
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Imanzadeh G, Ahmadi F, Zamanloo M, Mansoori Y. Tetrabutylammonium bromide media aza-Michael addition of 1,2,3,6-tetrahydrophthalimide to symmetrical fumaric esters and acrylic esters under solvent-free conditions. Molecules 2010; 15:7353-62. [PMID: 20966877 PMCID: PMC6259228 DOI: 10.3390/molecules15107353] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Revised: 10/11/2010] [Accepted: 10/11/2010] [Indexed: 11/17/2022] Open
Abstract
The aza-Michael addition of 1,2,3,6-tetrahydrophthalimide with symmetrical fumaric esters has been performed efficiently in a solvent-free system at 100 °C and using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a base in the presence of tetrabutylammonium bromide (TBAB). The products were obtained in good to high yields within 2.5-7.0 h. This reaction worked well on linear alkyl fumarates and was not effective with nonlinear alkyl fumarates. Although the reaction was also applicable to acrylates such as n-butyl acrylate, methacrylates and crotonates were not suitable Michael acceptors for this reaction.
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75
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Lee JW, Kang KS, Lee SH, Kim JY, Lee BK, Cho DW. Bone regeneration using a microstereolithography-produced customized poly(propylene fumarate)/diethyl fumarate photopolymer 3D scaffold incorporating BMP-2 loaded PLGA microspheres. Biomaterials 2010; 32:744-52. [PMID: 20933279 DOI: 10.1016/j.biomaterials.2010.09.035] [Citation(s) in RCA: 162] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2010] [Accepted: 09/14/2010] [Indexed: 11/19/2022]
Abstract
Bony defects have been three-dimensionally (3D) created in many clinical circumstances; however, many defects cannot be reconstructed because most of the current bony substitutes cannot provide the necessary exact 3D structure. Therefore, to overcome this limitation, a 3D scaffold with embedded growth factor-delivering microspheres was developed by solid free-form fabrication (SFF) technology using computer-aided design/manufacturing (CAD/CAM). In this study, BMP-2-loaded poly(DL-lactic-co-glycolic acid) (PLGA) microspheres were incorporated into a 3D scaffold that was fabricated using a microstereolithography (MSTL) system with a suspension of microspheres and a poly(propylene fumarate) (PPF)/diethyl fumarate (DEF) photopolymer. By measuring release profiles in vitro, we verified that the fabricated microsphere-containing 3D scaffold could gradually release growth factor. The effects of BMP-2 were also assessed in vitro by observing cell differentiation using MC3T3-E1 pre-osteoblasts. Finally, we confirmed that SFF scaffolds created by MSTL were superior to traditional scaffolds produced using a particulate leaching/gas foaming method. In addition, based on in vivo tests, the scaffolds that released BMP-2 promoted bone formation. Based on these results, we concluded that our 3D scaffold might be a useful tool for enhancing reconstruction quality in many complex bony defects that should be reconstructed using a customized 3D scaffold.
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