scholarly journals In Vitro Evaluation of Curcumin- and Quercetin-Loaded Nanoemulsions for Intranasal Administration: Effect of Surface Charge and Viscosity

Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 194
Author(s):  
Gustavo Vaz ◽  
Adryana Clementino ◽  
Evgenia Mitsou ◽  
Elena Ferrari ◽  
Francesca Buttini ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Water Solubility ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Drug Uptake ◽  
Chemical Degradation ◽  
Nasal Administration ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Cytotoxicity Studies

The nose-to-brain delivery of neuroprotective natural compounds is an appealing approach for the treatment of neurodegenerative diseases. Nanoemulsions containing curcumin (CUR) and quercetin (QU) were prepared by high-pressure homogenization and characterized physicochemically and structurally. A negative (CQ_NE−), a positive (CQ_NE+), and a gel (CQ_NEgel) formulation were developed. The mean particle size of the CQ_NE− and CQ_NE+ was below 120 nm, while this increased to 240 nm for the CQ_NEgel. The formulations showed high encapsulation efficiency and protected the CUR/QU from biological/chemical degradation. Electron paramagnetic resonance spectroscopy showed that the CUR/QU were located at the interface of the oil phase in the proximity of the surfactant layer. The cytotoxicity studies showed that the formulations containing CUR/QU protected human nasal cells from the toxicity evidenced for blank NEs. No permeation across an in vitro model nasal epithelium was evidenced for CUR/QU, probably due to their poor water-solubility and instability in physiological buffers. However, the nasal cells’ drug uptake showed that the total amount of CUR/QU in the cells was related to the NE characteristics (CQ_NE− > CQ_NE+ > CQ_NEgel). The method used allowed the obtainment of nanocarriers of an appropriate size for nasal administration. The treatment of the cells showed the protection of cellular viability, holding promise as an anti-inflammatory treatment able to prevent neurodegenerative diseases.

scholarly journals Nitric oxide interactions with cobalamins: biochemical and functional consequences

Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1857-1864 ◽  
Author(s):  
M Brouwer ◽  
W Chamulitrat ◽  
G Ferruzzi ◽  
DL Sauls ◽  
JB Weinberg
Keyword(s):  
Nitric Oxide ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
No Formation ◽  
Iron Nitrosyl ◽  
Wide Range ◽  
Functional Consequences

Abstract Nitric oxide (NO) is a paramagnetic gas that has been implicated in a wide range of biologic functions. The common pathway to evoke the functional response frequently involves the formation of an iron- nitrosyl complex in a target (heme) protein. In this study, we report on the interactions between NO and cobalt-containing vitamin B12 derivatives. Absorption spectroscopy showed that of the four Co(III) derivatives (cyanocobalamin [CN-Cbl], aquocobalamin [H2O-Cbl], adenosylcobalamin [Ado-Cbl], and methylcobalamin [MeCbl]), only the H2O- Cbl combined with NO. In addition, electron paramagnetic resonance spectroscopy of H2O-Cbl preparations showed the presence of a small amount of Cob-(II)alamin that was capable of combining with NO. The Co(III)-NO complex was very stable, but could transfer its NO moiety to hemoglobin (Hb). The transfer was accompanied by a reduction of the Co(III) to Co(II), indicating that NO+ (nitrosonium) was the leaving group. In accordance with this, the NO did not combine with the Hb Fe(II)-heme, but most likely with the Hb cysteine-thiolate. Similarly, the Co(III)-NO complex was capable of transferring its NO to glutathione. Ado-Cbl and Me-Cbl were susceptible to photolysis, but CN- Cbl and H2O-Cbl were not. The homolytic cleavage of the Co(III)-Ado or Co(III)-Me bond resulted in the reduction of the metal. When photolysis was performed in the presence of NO, formation of NO-Co(II) was observed. Co(II)-nitrosyl oxidized slowly to form Co(III)-nitrosyl. The capability of aquocobalamin to combine with NO had functional consequences. We found that nitrosylcobalamin had diminished ability to serve as a cofactor for the enzyme methionine synthase, and that aquocobalamin could quench NO-mediated inhibition of cell proliferation. Our in vitro studies therefore suggest that interactions between NO and cobalamins may have important consequences in vivo.

Estradiol replacement reverses ovariectomy-induced muscle contractile and myosin dysfunction in mature female mice

2007 ◽  
Vol 102 (4) ◽  
pp. 1387-1393 ◽  
Author(s):  
Amy L. Moran ◽  
Steven A. Nelson ◽  
Rachel M. Landisch ◽  
Gordon L. Warren ◽  
Dawn A. Lowe
Keyword(s):  
Skeletal Muscle ◽  
Contractile Function ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Eccentric Contraction ◽  
Mature Female ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Tetanic Force ◽  
Female Mice

Skeletal muscle contractility and myosin function decline following ovariectomy in mature female mice. In the present study we tested the hypothesis that estradiol replacement can reverse those declines. Four-month-old female C57BL/6 mice ( n = 69) were ovariectomized (OVX) or sham operated. Some mice were treated immediately with placebo or 17β-estradiol (OVX + E2) while other mice were treated 30 days postsurgery. Thirty or sixty days postsurgery, soleus muscles were assessed in vitro for contractile function and susceptibility to eccentric contraction-induced injury. Myosin structural dynamics was analyzed in extensor digitorum longus (EDL) muscles by electron paramagnetic resonance spectroscopy. Maximal isometric tetanic force was affected by estradiol status ( P < 0.001) being ∼10% less in soleus muscles from OVX compared with sham-operated mice [168 mN (SD 16.7) vs. 180 mN (SD 14.4)] and was restored in OVX + E2 mice [187 mN (SD 17.6)]. The fraction of strong-binding myosin during contraction was also affected ( P = 0.045) and was ∼15% lower in EDL muscles from OVX compared with OVX + E2 mice [0.263 (SD 0.034) vs. 0.311 (SD 0.022)]. Plasma estradiol levels were correlated with maximal isometric tetanic force ( r = 0.458; P < 0.001) and active stiffness ( r = 0.329; P = 0.044), indicating that circulating estradiol influenced muscle and myosin function. Estradiol was not effective in protecting muscle against an acute eccentric contraction-induced injury ( P ≥ 0.401) but did restore ovariectomy-induced increases in muscle wet mass caused by fluid accumulation. Collectively, estradiol had a beneficial effect on female mouse skeletal muscle.

scholarly journals Besifloxacin liposomes with positively charged additives for an improved topical ocular delivery

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Giselly Almeida dos Santos ◽  
Ricardo Ferreira-Nunes ◽  
Luciana Facco Dalmolin ◽  
Ana Carolina dos Santos Ré ◽  
Jorge Luiz Vieira Anjos ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Defense Mechanisms ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Drug Penetration ◽  
Current Application ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic ◽  
Positively Charged

Abstract Topical ophthalmic antibiotics show low efficacy due to the well-known physiological defense mechanisms of the eye, which prevents the penetration of exogenous substances. Here, we aimed to incorporate besifloxacin into liposomes containing amines as positively charged additives and to evaluate the influence of this charge on drug delivery in two situations: (i) iontophoretic and (ii) passive treatments. Hypothesis are (i) charge might enhance the electromigration component upon current application improving penetration efficiency for a burst drug delivery, and (ii) positive charge might prolong formulation residence time, hence drug penetration. Liposomes elaborated with phosphatidylcholine (LP PC) or phosphatidylcholine and spermine (LP PC: SPM) were stable under storage at 6 ºC for 30 days, showed mucoadhesive characteristics, and were non-irritant, according to HET-CAM tests. Electron paramagnetic resonance spectroscopy measurements showed that neither the drug nor spermine incorporations produced evident alterations in the fluidity of the liposome's membranes, which retained their structural stability even under iontophoretic conditions. Mean diameter and zeta potential were 177.2 ± 2.7 nm and − 5.7 ± 0.3 mV, respectively, for LP PC; and 175.4 ± 1.9 nm and + 19.5 ± 1.0 mV, respectively, for LP PC:SPM. The minimal inhibitory concentration (MIC) and the minimal bactericide concentration (MBC) of the liposomes for P. aeruginosa showed values lower than the commercial formulation (Besivance). Nevertheless, both formulations presented a similar increase in permeability upon the electric current application. Hence, liposome charge incorporation did not prove to be additionally advantageous for iontophoretic therapy. Passive drug penetration was evaluated through a novel in vitro ocular model that simulates the lacrimal flow and challenges the formulation resistance in the passive delivery situation. As expected, LP PC: SPM showed higher permeation than the control (Besivance). In conclusion, besifloxacin incorporation into positively charged liposomes improved passive topical delivery and can be a good strategy to improve topical ophthalmic treatments.

scholarly journals Tabotamp®, Respectively, Surgicel®, Increases the Cell Death of Neuronal and Glial Cells In Vitro

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2453
Author(s):  
Sandra Leisz ◽  
Marie-Luise Trutschel ◽  
Karsten Mäder ◽  
Christian Scheller ◽  
Christian Strauss ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Schwann Cells ◽  
Cell Lines ◽  
Ph Value ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Regenerated Cellulose ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Eloquent Areas

Oxidized regenerated cellulose (ORC) is an approved absorbable hemostat in neurosurgery, and contains 18–21% carboxylic acid groups. This modification leads to a low pH in aqueous solutions. Therefore, the aim of study was to analyze the pH-dependent effects of the ORC Tabotamp® on astrocytes, Schwann cells, and neuronal cells in vitro to investigate whether Tabotamp® is a suitable hemostat in cerebral eloquent areas. The ORC-dependent pH value changes were measured with (i) a pH meter, (ii) electron paramagnetic resonance spectroscopy, using pH-sensitive spin probes, and (iii) with fluorescence microscopy. Cell lines from neurons, astrocytes, and Schwann cells, as well as primary astrocytes were incubated with increasing areas of Tabotamp®. Cytotoxicity was detected using a fluorescence labeled DNA-binding dye. In addition, the wounding extent was analyzed via crystal violet staining of cell layers. The strongest pH reduction (to 2.2) was shown in phosphate buffered saline, whereas culture medium and cerebrospinal fluid demonstrated a higher buffer capacity during Tabotamp® incubation. In addition, we could detect a distance-dependent pH gradient by fluorescence microscopy. Incubation of Tabotamp® on cell monolayers led to detachment of covered cells and showed increased cytotoxicity in all tested cell lines and primary cells depending on the covered area. These in vitro results indicate that Tabotamp® may not be a suitable hemostat in cerebral eloquent areas.

scholarly journals The structure and reactivity of the HoxEFU complex from the cyanobacterium Synechocystis sp. PCC 6803

2020 ◽  
Vol 295 (28) ◽  
pp. 9445-9454
Author(s):  
Jacob H. Artz ◽  
Monika Tokmina-Lukaszewska ◽  
David W. Mulder ◽  
Carolyn E. Lubner ◽  
Kirstin Gutekunst ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Electron Flow ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Cellular Components ◽  
Electron Carriers ◽  
Electron Paramagnetic ◽  
Photosynthetic Electron Transfer

Cyanobacterial Hox is a [NiFe] hydrogenase that consists of the hydrogen (H2)-activating subunits HoxYH, which form a complex with the HoxEFU assembly to mediate reactions with soluble electron carriers like NAD(P)H and ferredoxin (Fdx), thereby coupling photosynthetic electron transfer to energy-transforming catalytic reactions. Researchers studying the HoxEFUYH complex have observed that HoxEFU can be isolated independently of HoxYH, leading to the hypothesis that HoxEFU is a distinct functional subcomplex rather than an artifact of Hox complex isolation. Moreover, outstanding questions about the reactivity of Hox with natural substrates and the site(s) of substrate interactions and coupling of H2, NAD(P)H, and Fdx remain to be resolved. To address these questions, here we analyzed recombinantly produced HoxEFU by electron paramagnetic resonance spectroscopy and kinetic assays with natural substrates. The purified HoxEFU subcomplex catalyzed electron transfer reactions among NAD(P)H, flavodoxin, and several ferredoxins, thus functioning in vitro as a shuttle among different cyanobacterial pools of reducing equivalents. Both Fdx1-dependent reductions of NAD+ and NADP+ were cooperative. HoxEFU also catalyzed the flavodoxin-dependent reduction of NAD(P)+, Fdx2-dependent oxidation of NADH and Fdx4- and Fdx11-dependent reduction of NAD+. MS-based mapping identified an Fdx1-binding site at the junction of HoxE and HoxF, adjacent to iron-sulfur (FeS) clusters in both subunits. Overall, the reactivity of HoxEFU observed here suggests that it functions in managing peripheral electron flow from photosynthetic electron transfer, findings that reveal detailed insights into how ubiquitous cellular components may be used to allocate energy flow into specific bioenergetic products.

scholarly journals A Second [2Fe-2S] Ferredoxin from Sphingomonas sp. Strain RW1 Can Function as an Electron Donor for the Dioxin Dioxygenase

2000 ◽  
Vol 182 (8) ◽  
pp. 2238-2244 ◽  
Author(s):  
Jean Armengaud ◽  
Jacques Gaillard ◽  
Kenneth N. Timmis
Keyword(s):  
Electron Donor ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
In Vitro Assays ◽  
Resonance Spectroscopy ◽  
Hydrogen Electrode ◽  
Visible Absorption ◽  
Paramagnetic Resonance ◽  
Reading Frame

ABSTRACT The first step in the degradation of dibenzofuran and dibenzo-p-dioxin by Sphingomonas sp. strain RW1 is carried out by dioxin dioxygenase (DxnA1A2), a ring-dihydroxylating enzyme. An open reading frame (fdx3) that could potentially specify a new ferredoxin has been identified downstream ofdxnA1A2, a two-cistron gene (J. Armengaud, B. Happe, and K. N. Timmis, J. Bacteriol. 180:3954–3966, 1998). In the present study, we report a biochemical analysis of Fdx3 produced inEscherichia coli. This third ferredoxin thus far identified in Sphingomonas sp. strain RW1 contained a putidaredoxin-type [2Fe-2S] cluster which was characterized by UV-visible absorption spectrophotometry and electron paramagnetic resonance spectroscopy. The midpoint redox potential of this ferredoxin (E′0 = −247 ± 10 mV versus normal hydrogen electrode at pH 8.0) is similar to that exhibited by Fdx1 (−245 mV), a homologous ferredoxin previously characterized inSphingomonas sp. strain RW1. In in vitro assays, Fdx3 can be reduced by RedA2 (a reductase similar to class I cytochrome P-450 reductases), previously isolated from Sphingomonas sp. strain RW1. RedA2 exhibits a Km value of 3.2 ± 0.3 μM for Fdx3. In vivo coexpression of fdx3and redA2 with dxnA1A2 confirmed that Fdx3 can serve as an electron donor for the dioxin dioxygenase.

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