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Bassler MC, Rammler T, Wackenhut F, Zur Oven-Krockhaus S, Secic I, Ritz R, Meixner AJ, Brecht M. Accumulation and penetration behavior of hypericin in glioma tumor spheroids studied by fluorescence microscopy and confocal fluorescence lifetime imaging microscopy. Anal Bioanal Chem 2022; 414:4849-4860. [PMID: 35538227 PMCID: PMC9234035 DOI: 10.1007/s00216-022-04107-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/14/2022] [Accepted: 04/28/2022] [Indexed: 12/17/2022]
Abstract
Glioblastoma WHO IV belongs to a group of brain tumors that are still incurable. A promising treatment approach applies photodynamic therapy (PDT) with hypericin as a photosensitizer. To generate a comprehensive understanding of the photosensitizer-tumor interactions, the first part of our study is focused on investigating the distribution and penetration behavior of hypericin in glioma cell spheroids by fluorescence microscopy. In the second part, fluorescence lifetime imaging microscopy (FLIM) was used to correlate fluorescence lifetime (FLT) changes of hypericin to environmental effects inside the spheroids. In this context, 3D tumor spheroids are an excellent model system since they consider 3D cell-cell interactions and the extracellular matrix is similar to tumors in vivo. Our analytical approach considers hypericin as probe molecule for FLIM and as photosensitizer for PDT at the same time, making it possible to directly draw conclusions of the state and location of the drug in a biological system. The knowledge of both state and location of hypericin makes a fundamental understanding of the impact of hypericin PDT in brain tumors possible. Following different incubation conditions, the hypericin distribution in peripheral and central cryosections of the spheroids were analyzed. Both fluorescence microscopy and FLIM revealed a hypericin gradient towards the spheroid core for short incubation periods or small concentrations. On the other hand, a homogeneous hypericin distribution is observed for long incubation times and high concentrations. Especially, the observed FLT change is crucial for the PDT efficiency, since the triplet yield, and hence the O2 activation, is directly proportional to the FLT. Based on the FLT increase inside spheroids, an incubation time > 30 min is required to achieve most suitable conditions for an effective PDT.
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Affiliation(s)
- Miriam C Bassler
- Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstr. 150, 72762, Reutlingen, Germany.,Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Tim Rammler
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Frank Wackenhut
- Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstr. 150, 72762, Reutlingen, Germany.
| | - Sven Zur Oven-Krockhaus
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Ivona Secic
- Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstr. 150, 72762, Reutlingen, Germany
| | - Rainer Ritz
- Department of Neurosurgery, Schwarzwald-Baar Clinic, Klinikstr. 11, 78052, Villingen-Schwenningen, Germany
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Marc Brecht
- Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstr. 150, 72762, Reutlingen, Germany. .,Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.
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2
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Keša P, Antalík M. Determination of p K a constants of hypericin in aqueous solution of the anti-allergic hydrotropic drug Cromolyn disodium salt. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.03.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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3
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Maslaňáková M, Balogová L, Miškovský P, Tkáčová R, Štroffeková K. Anti- and Pro-apoptotic Bcl2 Proteins Distribution and Metabolic Profile in Human Coronary Aorta Endothelial Cells Before and After HypPDT. Cell Biochem Biophys 2016; 74:435-47. [PMID: 27314518 DOI: 10.1007/s12013-016-0740-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 06/09/2016] [Indexed: 11/24/2022]
Abstract
Understanding apoptosis regulatory mechanisms in endothelial cells (ECs) has great importance for the development of novel therapy strategies for cancer and cardiovascular pathologies. An oxidative stress with the generation of reactive oxygen species (ROS) is a common mechanism causing ECs' dysfunction and apoptosis. The generation of ROS can be triggered by various stimuli including photodynamic therapy (PDT). In most PDT treatments, photosensitizer (PS) is administered systemically, and thus, possibility of high exposure to PS in the ECs remains high. PS accumulation in ECs may be clinically relevant even without PDT, if PS molecules affect the pro-apoptotic cascade without illumination. In the present work, we focused on Hypericin (Hyp) and HypPDT effects on the cell viability, oxidative stress, and the distribution of Bcl2 family members in human coronary artery endothelial (HCAEC) cells. Our findings show that the presence of Hyp itself has an effect on cell viability, oxidative stress, and the distribution of Bcl2 family members, without affecting the mitochondria function. In contrast, HypPDT resulted in mitochondria dysfunction, further increase of oxidative stress and effect on the distribution of Bcl2 family members, and in primarily necrotic type of death in HCAEC cells.
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Affiliation(s)
- Mária Maslaňáková
- Department of Biophysics, Faculty of Natural Sciences, PJ Safarik University, Jesenna 5, Kosice, Slovakia
| | - Lucia Balogová
- Department of Biophysics, Faculty of Natural Sciences, PJ Safarik University, Jesenna 5, Kosice, Slovakia
| | - Pavol Miškovský
- Department of Biophysics, Faculty of Natural Sciences, PJ Safarik University, Jesenna 5, Kosice, Slovakia.,Center of Interdisciplinary Biosciences, Faculty of Natural Sciences, PJ Safarik University, Kosice, Slovakia
| | - Ružena Tkáčová
- Department of Respiratory Medicine, Faculty of Medicine, P.J. Safarik University, Kosice, Slovakia
| | - Katarína Štroffeková
- Department of Biophysics, Faculty of Natural Sciences, PJ Safarik University, Jesenna 5, Kosice, Slovakia.
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4
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Sánchez-Lombardo I, Baruah B, Alvarez S, Werst KR, Segaline NA, Levinger NE, Crans DC. Size and shape trump charge in interactions of oxovanadates with self-assembled interfaces: application of continuous shape measure analysis to the decavanadate anion. NEW J CHEM 2016. [DOI: 10.1039/c5nj01788b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using 51V NMR spectroscopy, dynamic light scattering and continuous shape analysis to characterize two polyoxometalate-encapsulation in reverse micelles.
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Affiliation(s)
| | - Bharat Baruah
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
- Department of Chemistry
| | - Santiago Alvarez
- Departament de Química Inorganica
- Institut de Química Teorica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
| | - Katarina R. Werst
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
| | | | - Nancy E. Levinger
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
| | - Debbie C. Crans
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
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5
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Lomovskii IO, Politov AA. Mechanochemical Neutralization of Hypericin in Hypericum perforatum Studied by Spectroluminescence. Chem Nat Compd 2014. [DOI: 10.1007/s10600-014-0923-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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6
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Chatkon A, Chatterjee PB, Sedgwick MA, Haller KJ, Crans DC. Counterion Affects Interaction with Interfaces: The Antidiabetic Drugs Metformin and Decavanadate. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201201345] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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7
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Johnson MD, Lorenz BB, Wilkins PC, Lemons BG, Baruah B, Lamborn N, Stahla M, Chatterjee PB, Richens DT, Crans DC. Switching Off Electron Transfer Reactions in Confined Media: Reduction of [Co(dipic)2]− and [Co(edta)]− by Hexacyanoferrate(II). Inorg Chem 2012; 51:2757-65. [DOI: 10.1021/ic201247v] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael D. Johnson
- Department
of Chemistry and
Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003-8001, United States
| | - Bret B. Lorenz
- Department
of Chemistry and
Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003-8001, United States
| | - Patricia C. Wilkins
- Department
of Chemistry and
Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003-8001, United States
| | - Brant G. Lemons
- Department
of Chemistry and
Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003-8001, United States
| | - Bharat Baruah
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
| | - Nathan Lamborn
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
| | - Michelle Stahla
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
| | - Pabitra B. Chatterjee
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
| | - David T. Richens
- Department
of Chemistry and
Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003-8001, United States
| | - Debbie C. Crans
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872,
United States
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Shrestha R, Choi TY, Chang W, Kim D. A high-precision micropipette sensor for cellular-level real-time thermal characterization. SENSORS 2011; 11:8826-35. [PMID: 22164108 PMCID: PMC3231465 DOI: 10.3390/s110908826] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 09/07/2011] [Accepted: 09/07/2011] [Indexed: 11/16/2022]
Abstract
We report herein development of a novel glass micropipette thermal sensor fabricated in a cost-effective manner, which is capable of measuring steady thermal fluctuation at spatial resolution of ∼2 μm with an accuracy of ±0.01 °C. We produced and tested various micrometer-sized sensors, ranging from 2 μm to 30 μm. The sensor comprises unleaded low-melting-point solder alloy (Sn-based) as a core metal inside a pulled borosilicate glass pipette and a thin film of nickel coating outside, creating a thermocouple junction at the tip. The sensor was calibrated using a thermally insulated calibration chamber, the temperature of which can be controlled with an accuracy of ±0.01 °C, and the thermoelectric power (Seebeck coefficient) of the sensor was recorded from 8.46 to 8.86 μV/°C. We have demonstrated the capability of measuring temperatures at a cellular level by inserting our temperature sensor into the membrane of a live retinal pigment epithelium cell subjected to a laser beam with a focal spot of 6 μm. We measured transient temperature profiles and the maximum temperatures were in the range of 38-55 ± 0.5 °C.
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Affiliation(s)
- Ramesh Shrestha
- Department of Mechanical and Energy Engineering, University of North Texas, 3940 N. Elm St, Denton, TX 76207, USA; E-Mail: E-Mail:
| | - Tae-Youl Choi
- Department of Mechanical and Energy Engineering, University of North Texas, 3940 N. Elm St, Denton, TX 76207, USA; E-Mail: E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-940-565-2198; Fax: +1-940-369-8675
| | - Wonseok Chang
- Department of Nanomechanical Systems, Korea Institute of Machinery and Materials, 156 Gajungbukno, Yuseong-gu, Daejeon 305-343, Korea; E-Mail:
| | - Donsik Kim
- Department of Mechanical Engineering, POSTECH, San 31 Hyoja-Dong, Nam-Gu, Pohang, Gyungbuk 790-784, Korea; E-Mail:
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9
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McPhee JT, Scott E, Levinger NE, Van Orden A. Cy3 in AOT Reverse Micelles I. Dimer Formation Revealed through Steady-State and Time-Resolved Spectroscopy. J Phys Chem B 2011; 115:9576-84. [DOI: 10.1021/jp200126f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Jeffrey T. McPhee
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Eric Scott
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Nancy E. Levinger
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Alan Van Orden
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
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10
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McPhee JT, Scott E, Levinger NE, Van Orden A. Cy3 in AOT Reverse Micelles II. Probing Intermicellar Interactions Using Fluorescence Correlation Spectroscopy. J Phys Chem B 2011; 115:9585-92. [DOI: 10.1021/jp2001282] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jeffrey T McPhee
- Colorado State University, Department of Chemistry, Fort Collins, Colorado 80523, USA
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11
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Levinger NE, Rubenstrunk LC, Baruah B, Crans DC. Acidification of reverse micellar nanodroplets by atmospheric pressure CO2. J Am Chem Soc 2011; 133:7205-14. [PMID: 21506532 DOI: 10.1021/ja2011737] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Water absorption of atmospheric carbon dioxide lowers the solution pH due to carbonic acid formation. Bulk water acidification by CO(2) is well documented, but significantly less is known about its effect on water in confined spaces. Considering its prominence as a greenhouse gas, the importance of aerosols in acid rain, and CO(2)-buffering in cellular systems, surprisingly little information exists about the absorption of CO(2) by nanosized water droplets. The fundamental interactions of CO(2) with water, particularly in nanosized structures, may influence a wide range of processes in our technological society. Here results from experiments investigating the uptake of gaseous CO(2) by water pools in reverse micelles are presented. Despite the small number of water molecules in each droplet, changes in vanadium probes within the water pools, measured using vanadium-51 NMR spectroscopy, indicate a significant drop in pH after CO(2) introduction. Collectively, the pH-dependent vanadium probes show CO(2) dissolves in the nanowater droplets, causing the reverse micelle acidity to increase.
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Affiliation(s)
- Nancy E Levinger
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA.
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12
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Gbur P, Dedic R, Chorvat Jr D, Miskovsky P, Hala J, Jancura D. Time-resolved Luminescence and Singlet Oxygen Formation After Illumination of the Hypericin-Low-density Lipoprotein Complex. Photochem Photobiol 2009; 85:816-23. [DOI: 10.1111/j.1751-1097.2008.00483.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Baruah B, Swafford LA, Crans DC, Levinger NE. Do Probe Molecules Influence Water in Confinement? J Phys Chem B 2008; 112:10158-64. [DOI: 10.1021/jp800390t] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Bharat Baruah
- Department of Chemistry, Colorado State University, Colorado 80523-1872
| | - Laura A. Swafford
- Department of Chemistry, Colorado State University, Colorado 80523-1872
| | - Debbie C. Crans
- Department of Chemistry, Colorado State University, Colorado 80523-1872
| | - Nancy E. Levinger
- Department of Chemistry, Colorado State University, Colorado 80523-1872
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14
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Stahla ML, Baruah B, James DM, Johnson MD, Levinger NE, Crans DC. 1H NMR studies of aerosol-OT reverse micelles with alkali and magnesium counterions: preparation and analysis of MAOTs. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:6027-6035. [PMID: 18484757 DOI: 10.1021/la8002965] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Simple procedures and characterization of a series of well-defined precursors are described for preparation of a unique microenvironment in nanoreactors, reverse micelles. The Na(+), K(+), Rb(+), Cs(+), and Mg(2+) surfactants were prepared using liquid-liquid ion exchange using chloride and nitrate salts. The surfactants were characterized using (1)H NMR spectroscopy and a variety of other techniques. (1)H NMR spectroscopy was found to be a sensitive probe for characterization of the size of the nanoreactor as well as its water content. (1)H NMR spectra can be used for detailed characterization of reactions in confined environments when counterion effects are likely to be important. (1)H NMR spectroscopy revealed two separate peaks corresponding to water in Mg(AOT)2 samples; one peak arises from water coordinated to the Mg(2+) ion while the other peak arises from bulk water. The two water signals arise directly from the slow exchange of the water coordinated to Mg(2+) in these microemulsions with water in the water pool, and provide an opportunity to study hydration of Mg(2+). This work thus extends the potential use of MAOT microemulsions for applications such as in green chemistry.
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Affiliation(s)
- Michelle L Stahla
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
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15
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Impairment of ascorbic acid’s anti-oxidant properties in confined media: Inter and intramolecular reactions with air and vanadate at acidic pH. J Inorg Biochem 2008; 102:1334-47. [DOI: 10.1016/j.jinorgbio.2008.01.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 01/04/2008] [Accepted: 01/10/2008] [Indexed: 11/22/2022]
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16
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Mallick A, Purkayastha P, Chattopadhyay N. Photoprocesses of excited molecules in confined liquid environments: An overview. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2007. [DOI: 10.1016/j.jphotochemrev.2007.06.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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Mukherjee S, Chowdhury P, Gai F. Tuning the cooperativity of the helix-coil transition by aqueous reverse micelles. J Phys Chem B 2007; 110:11615-9. [PMID: 16800453 DOI: 10.1021/jp062362k] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We show in this letter that the thermodynamic properties of helical peptides can be tuned by varying the degrees of backbone hydration. The latter was achieved by solubilizing peptides in the water pool of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles with different water contents or w0 values. Far-UV circular dichroism measurements on a series of alanine-rich peptides indicate that the helicity of shorter peptides is significantly increased in AOT reverse micelles at low w0 values, as compared to the corresponding helical content in buffer. This result therefore corroborates the previous simulation studies suggesting that desolvation of backbone CO and NH groups increases the stability of monomeric helices. In addition, it was found that the thermal unfolding transition of these peptides can either be very noncooperative or very cooperative, depending on w0 and peptide chain length. A simple model, which considers the heterogeneous distribution of the water molecules inside the polar core of AOT reverse micelles as well as the geometric confinement effect exerted on the peptide by the reverse micelles, was used to interpret these results.
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18
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Baruah B, Crans DC, Levinger NE. Simple oxovanadates as multiparameter probes of reverse micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:6510-8. [PMID: 17489609 DOI: 10.1021/la063072y] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Using a wide range of different methods, researchers have found that the environment inside reverse micelles differs from bulk aqueous solution in many ways. Here, we present a new tool, a series of aqueous oxovanadium(V) reactions, to probe pH, viscosity, and ionic strength in the aqueous interior of reverse micelles. In addition to their potential as anionic probe analogues to phosphates, simple oxovanadium(V) compounds have equilibrium characteristics in aqueous media exquisitely sensitive to their environment. Therefore, the speciation of vanadate equilibria can be used as a parameter to characterize the intramicellar medium. Vanadate speciation is monitored through 51V NMR spectroscopy, which also yields information through chemical shifts and linewidths of spectral features. The speciation observed suggests that the relative acidity of a basic vanadate stock solution is slightly reduced in large, w0 >or= 12, reverse micelles, but that for smaller reverse micelles, speciation reflects the strong interaction of these negatively charged oxometalates with the reverse micelle and suggest an increased solution viscosity in the reverse micelles. This interpretation is obtained through different responses closely linked to the reverse micellar size and the specific conditions in the stock solutions used to form reverse micelles.
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Affiliation(s)
- Bharat Baruah
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
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19
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Mukherjee S, Chowdhury P, Gai F. Infrared Study of the Effect of Hydration on the Amide I Band and Aggregation Properties of Helical Peptides. J Phys Chem B 2007; 111:4596-602. [PMID: 17419612 DOI: 10.1021/jp0689060] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The amide I' band of a polypeptide is sensitive not only to its secondary structure content but also to its environment. In this study we show how degrees of hydration affect the underlying spectral features of the amide I' band of two alanine-based helical peptides. This is achieved by solubilizing these peptides in the water pool of sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles with different water contents or w0 values. In agreement with several earlier studies, our results show that the amide I' band arising from a group of dehydrated helical amides is centered at approximately 1650 cm-1, whereas hydration shifts this frequency toward lower wavenumbers. More importantly, temperature-dependent infrared studies further show that these helical peptides undergo a thermally induced conformational transition in reverse micelles of low w0 values (e.g., w0=6), resulting in soluble peptide aggregates rich in antiparallel beta-sheets. Interestingly, however, increasing w0 or water content leads to an increase in the onset temperature at which such beta-aggregates begin to form. Therefore, these results provide strong evidence suggesting that dehydration facilitates aggregate formation and that removal of water imposes a free energy barrier to peptide association and aggregation, a feature that has been suggested in recent simulation studies focusing on the mechanism of beta-amyloid formation.
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Affiliation(s)
- Smita Mukherjee
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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20
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Miskovsky P, Hritz J, Sanchez-Cortes S, Fabriciova G, Ulicny J, Chinsky L. Interaction of Hypericin with Serum Albumins: Surface-enhanced Raman Spectroscopy, Resonance Raman Spectroscopy and Molecular Modeling Study¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2001)0740172iohwsa2.0.co2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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Park J, Datta A, Chowdhury PK, Petrich JW. Is the Excited-State H-atom Transfer in Hypericin Concerted?¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2001)0730105itesha2.0.co2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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22
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Douhal A, Angulo G, Gil M, Organero JA, Sanz M, Tormo L. Observation of Three Behaviors in Confined Liquid Water within a Nanopool Hosting Proton-Transfer Reactions. J Phys Chem B 2007; 111:5487-93. [PMID: 17451268 DOI: 10.1021/jp068764+] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this contribution, we report on studies of rotational and diffusional dynamics of 7-hydroxyquinoline (7HQ) within a reverse micelle (RM) containing different amounts of water. Analyzed in terms of the wobbling-in-a-cone model, the data reveal structural and dynamical properties of the nanopool. We clearly observed three regions in the behavior of confined water molecules within the RM hosting a double proton-transfer reaction between the probe and water. This observation remarkably reproduces the change of calculated water density within this life-mimicking medium. The number of water molecules per AOT head in the transition regions changes from 2 to 5, the latter being very near to the full solvation number (6) of the RM heads. Moreover, the H-bonds breaking and making within the RM to give new structures of the probe strongly affect the environment fluidization in different extents, reflected in different relaxation times of these structures; however, they are of similar sizes. We discuss the role of RM confinement and the proton-transfer dynamics on the behavior of water and their relationships to the packing of water molecules in the studied range of concentrations.
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Affiliation(s)
- Abderrazzak Douhal
- Departamento de Química Física, Sección de Químicas, Facultad de Ciencias del Medio Ambiente, Universidad de Castilla-La Mancha, Avenida Carlos III, S.N., 45071 Toledo, Spain.
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23
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Baruah B, Roden JM, Sedgwick M, Correa NM, Crans DC, Levinger NE. When Is Water Not Water? Exploring Water Confined in Large Reverse Micelles Using a Highly Charged Inorganic Molecular Probe. J Am Chem Soc 2006; 128:12758-65. [PMID: 17002370 DOI: 10.1021/ja0624319] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The interior water pool of aerosol OT (AOT) reverse micelles tends toward bulk water properties as the micelle size increases. Thus, deviations from bulk water behavior in large reverse micelles are less expected than in small reverse micelles. Probing the interior water pool of AOT reverse micelles with a highly charged decavanadate (V(10)) oligomer using (51)V NMR spectroscopy shows distinct changes in solute environment. For example, when an acidic stock solution of protonated V(10) is placed in a reverse micelle, the (51)V chemical shifts show that the V(10) is deprotonated consistent with a decreased proton concentration in the intramicellar water pool. Results indicate that a proton gradient exists inside the reverse micelles, leaving the interior neutral while the interfacial region is acidic.
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Affiliation(s)
- Bharat Baruah
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA
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Crans DC, Rithner CD, Baruah B, Gourley BL, Levinger NE. Molecular probe location in reverse micelles determined by NMR dipolar interactions. J Am Chem Soc 2006; 128:4437-45. [PMID: 16569021 DOI: 10.1021/ja0583721] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The location and interactions of solutes in microheterogeneous environments, such as reverse micelles, critically influence understanding of many phenomena that utilize probe molecules to characterize properties in chemical, biological, and physical systems. The information gained in such studies depends substantially on the location of the probe used. Often, intuition leads to the assumption that ionic probe molecules reside in the polar water pool of a system. In this work, the location of a charged polar transition metal coordination complex in a reverse micellar system is determined using NMR spectroscopy. Despite the expected Coulomb repulsion between the surfactant headgroups and the negatively charged complex, the complex spends significant time penetrating into the hydrophobic portion of the reverse micellar interface. These results challenge the assumption that ionic probe molecules reside solvated by water in microheterogeneous environments and suggest that probe molecule location be carefully considered before interpreting data from similar systems.
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Affiliation(s)
- Debbie C Crans
- Department of Chemistry, Colorado State University, Fort Collins, 80523-1872, USA.
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Crans DC, Baruah B, Levinger NE. Oxovanadates: a novel probe for studying lipid–water interfaces. Biomed Pharmacother 2006; 60:174-81. [PMID: 16600566 DOI: 10.1016/j.biopha.2006.02.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Accepted: 02/13/2006] [Indexed: 11/24/2022] Open
Abstract
How water, metabolites and proteins associate and traverse the lipid interface is generally investigated by using probes with spectroscopic handles. Cellular confinement limits the tools of investigation to indirect approaches. Studies of a variety of different probes become important to understand the effects of confinement on chemical reactions and biological function. Confinement of water affects the properties of water and this effect is important for cellular systems. A versatile model system for studying the effect of water confinement on biological processes uses reverse micelles (RMs). Molecular probes are also used to investigate environments that are not readily accessible to direct measurements. Most of the dyes in use contain large hydrophobic chromophores and do not have size and structural flexibility to probe a surface that is both hydrophobic and hydrophilic as common in biological systems. We present the use of vanadium-containing probes for exploration of the fundamental properties of restricted water and lipid interfaces in RMs. The presence of a vanadium atom in these probes provides multiple handles such as chemical shifts, signal linewidth and lifetime experiments in the quadrupolar 51V nuclei as well in 1H and 13C nuclei for investigations. The quadrupolar nuclei have a greater battery of useful spectroscopic parameters and combined with the conventional methods provide multiple handles in one probe. Furthermore, the vanadium-containing probe structure, charge and polarity can be modified for use in various biological settings. Here we introduce the concept and describe a few applications of this approach.
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Affiliation(s)
- Debbie C Crans
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA.
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Williams FB, Sander LC, Wise SA, Girard J. Development and evaluation of methods for determination of naphthodianthrones and flavonoids in St. John's wort. J Chromatogr A 2006; 1115:93-102. [PMID: 16554056 DOI: 10.1016/j.chroma.2006.02.078] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2005] [Revised: 02/18/2006] [Accepted: 02/24/2006] [Indexed: 11/25/2022]
Abstract
Several major constituents in St. John's wort were determined for a homogenized plant sample. Three extraction techniques were evaluated: Soxhlet extraction, pressurized-fluid extraction (PFE), and sonication extraction. Levels of nine constituents (chlorogenic acid, rutin, hyperoside, isoquercitrin, quercitrin, quercetin, amentoflavone, pseudohypericin, and hypericin) were measured using liquid chromatography with ultraviolet/visible absorbance, mass spectrometric, and fluorescence detection. Levels of total naphthodianthrones determined by liquid chromatography (LC) with absorbance detection at 590 nm were compared with levels determined by direct spectrophotometry at the same wavelength. Additionally, the methods described in this paper were applied to several brands of St. John's wort finished products.
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Affiliation(s)
- Felicia B Williams
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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27
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Skalkos D, Gioti E, Stalikas CD, Meyer H, Papazoglou TG, Filippidis G. Photophysical properties of Hypericum perforatum L. extracts--novel photosensitizers for PDT. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2006; 82:146-51. [PMID: 16388961 DOI: 10.1016/j.jphotobiol.2005.11.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Revised: 08/22/2005] [Accepted: 11/01/2005] [Indexed: 11/29/2022]
Abstract
We report the preparation of the methanolic extract (ME), and polar methanolic fraction (PMF) from the plant Hypericum perforatum L. The extracts contain various photosensitizing constituents such as naphthodianthrone derivatives (in 1.37% w/w), and chlorophylls (in 0.08% w/w). Upon light emission these constituents can be activated, providing photodynamic properties to the extracts, and making them a potent, new class, natural photosensitizers for use in photodynamic therapy (PDT), and photodynamic diagnosis (PDD). The absorbance spectra of the extracts are similar to the spectrum of hypericin, the main naphthodianthrone identified within, with two major bands at 548 and 590 nm. The fluorescence spectra in ethanol exhibit two main bands around 595 and 640 nm, in accordance with the spectrum of pure hypericin. The fluorescence intensity of PMF at 595 nm is only eight times less than the intensity of pure hypericin at the same wavelength, even though its hypericin concentration is only 0.57% w/w. The dependence of the PMF fluorescence signal on the pH of the medium, alone and in comparison with the signal of hypericin, has been investigated. PMF signal fades steadily, and smoothly both in acidic, and basic environment.
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Affiliation(s)
- D Skalkos
- Department of Materials Science and Engineering, University of Ioannina, Ioannina GR-45110, Greece.
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Plaza P, Mahet M, Tchaikovskaya ON, Martin MM. Excitation energy effect on the early photophysics of hypericin in solution. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Chowdhury P, Das K, Datta A, Liu WZ, Zhang HY, Petrich J. A comparison of the excited-state processes of nearly symmetrical perylene quinones: hypocrellin A and hypomycin B. J Photochem Photobiol A Chem 2002. [DOI: 10.1016/s1010-6030(02)00309-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Miskovsky P, Hritz J, Sanchez-Cortes S, Fabriciova G, Ulicny J, Chinsky L. Interaction of hypericin with serum albumins: surface-enhanced Raman spectroscopy, resonance Raman spectroscopy and molecular modeling study. Photochem Photobiol 2001; 74:172-83. [PMID: 11547551 DOI: 10.1562/0031-8655(2001)074<0172:iohwsa>2.0.co;2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Surface-enhanced Raman spectroscopy, resonance Raman spectroscopy and molecular modeling were employed to study the interaction of hypericin (Hyp) with human (HSA), rat (RSA) and bovine (BSA) serum albumins. The identification of the binding site of Hyp in serum albumins as well as the structural model for Hyp/HSA complex are presented. The interactions mainly reflect: (1) a change of the strength of H bonding at the N1-H site of Trp; (2) a change of the Trp side-chain conformation; (3) a change of the hydrophobicity of the Trp environment; and (4) a formation of an H-bond between the carbonyl group of Hyp and a proton donor in HSA and RSA which leads to a protonated-like carbonyl in Hyp. Our results indicate that Hyp is rigidly bound in IIA subdomain of HSA close to Trp214 (distance 5.12 A between the centers of masses). In the model presented the carbonyl group of Hyp is hydrogen bonded to Asn458. Two other candidates for hydrogen bonds have been identified between the bay-region hydroxyl group of Hyp and the carbonyl group of the Trp214 peptidic link and between the peri-region hydroxyl group of Hyp and the Asn458 carbonyl group. It is shown that the structures of the Hyp/HSA and Hyp/RSA complexes are similar to, and in some aspects different from, those found for the Hyp/BSA complex. The role of aminoacid sequence in the IIA subdomains of HSA, RSA and BSA is discussed to explain the observed differences.
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Affiliation(s)
- P Miskovsky
- Department of Biophysics, P. J. Safarik University, Jesenna, Kosice, Slovak Republic.
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Abstract
The excited-state intramolecular H-atom transfer of hypericin (Hyp) was investigated as a function of pH in monodispersed reverse micelles formed by sodium bis(2-ethylhexyl)sulfosuccinate/heptane/water and in complexes with Tb3+ under conditions in which one of the two carbonyl groups of Hyp is incapable of accepting a hydrogen atom. The results of pump-probe transient absorption experiments provide no evidence for a concerted H-atom transfer mechanism.
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Affiliation(s)
- J Park
- Department of Chemistry, Iowa State University, Ames 50011, USA
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