Water soluble cationic porphyrin showing pH-dependent optical responses to G-quadruplexes: Applications in pH-sensing and DNA logic gate

2016 ◽  
Vol 237 ◽  
pp. 179-189 ◽  
Author(s):  
Yan-Fang Huo ◽  
Li-Na Zhu ◽  
Xiao-Yu Li ◽  
Gui-Mei Han ◽  
De-Ming Kong
Keyword(s):  
Logic Gate ◽  
Water Soluble ◽  
Ph Sensing ◽  
Cationic Porphyrin ◽  
Optical Responses ◽  
Ph Dependent

A water-soluble cationic porphyrin showing pH-dependent G-quadruplex recognition specificity and DNA photocleavage activity

RSC Advances ◽  
2015 ◽  
Vol 5 (59) ◽  
pp. 47709-47717 ◽  
Author(s):  
Ting Zhao ◽  
Ya-Ling Wang ◽  
Li-Na Zhu ◽  
Yan-Fang Huo ◽  
Yong-Jian Wang ◽  
...  
Keyword(s):  
Water Soluble ◽  
Duplex Dna ◽  
Dna Photocleavage ◽  
Cationic Porphyrin ◽  
Recognition Specificity ◽  
G Quadruplex ◽  
Ph Dependent

A new water-soluble cationic porphyrin was synthesized. It shows pH-dependent G-quadruplex recognition specificity against duplex DNA, pH-dependent photocleavage activity towards duplex DNA and pH-dependent phototoxicity to cells.

scholarly journals Mechanistic Basis of pH-Dependent 5-Flucytosine Resistance inAspergillus fumigatus

2018 ◽  
Vol 62 (6) ◽  
Author(s):  
Fabio Gsaller ◽  
Takanori Furukawa ◽  
Paul D. Carr ◽  
Bharat Rash ◽  
Christoph Jöchl ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Fungal Pathogens ◽  
Regulatory Protein ◽  
Transcriptional Regulators ◽  
Primary Factor ◽  
Ph Sensing ◽  
Content Type ◽  
Ph Dependent ◽  
Mechanistic Basis

ABSTRACTThe antifungal drug 5-flucytosine (5FC), a derivative of the nucleobase cytosine, is licensed for the treatment of fungal diseases; however, it is rarely used as a monotherapeutic to treatAspergillusinfection. Despite being potent against other fungal pathogens, 5FC has limited activity againstAspergillus fumigatuswhen standardin vitroassays are used to determine susceptibility. However, in modifiedin vitroassays where the pH is set to pH 5, the activity of 5FC increases significantly. Here we provide evidence thatfcyB, a gene that encodes a purine-cytosine permease orthologous to known 5FC importers, is downregulated at pH 7 and is the primary factor responsible for the low efficacy of 5FC at pH 7. We also uncover two transcriptional regulators that are responsible for the repression offcyBand, consequently, mediators of 5FC resistance, the CCAAT binding complex (CBC) and the pH regulatory protein PacC. We propose that the activity of 5FC might be enhanced by the perturbation of factors that repressfcyBexpression, such as PacC or other components of the pH-sensing machinery.

scholarly journals Ratiometric pH Sensing and Imaging in Living Cells with Dual-Emission Semiconductor Polymer Dots

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2923
Author(s):  
Piaopiao Chen ◽  
Iqra Ilyas ◽  
Su He ◽  
Yichen Xing ◽  
Zhigang Jin ◽  
...  
Keyword(s):  
Fluorescent Dyes ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Fluorescein Isothiocyanate ◽  
Water Soluble ◽  
Ph Sensing ◽  
Dual Emission ◽  
Polymer Dots ◽  
Ratiometric Ph Sensing

Polymer dots (Pdots) represent newly developed semiconductor polymer nanoparticles and exhibit excellent characteristics as fluorescent probes. To improve the sensitivity and biocompatibility of Pdots ratiometric pH biosensors, we synthesized 3 types of water-soluble Pdots: Pdots-PF, Pdots-PP, and Pdots-PPF by different combinations of fluorescent dyes poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO), poly[(9,9-dioctyl-fluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1′,3}-thiadazole)] (PFBT), and fluorescein isothiocyanate (FITC). We found that Pdots-PPF exhibits optimal performance on pH sensing. PFO and FITC in Pdots-PPF produce pH-insensitive (λ = 439 nm) and pH-sensitive (λ = 517 nm) fluorescence respectively upon a single excitation at 380 nm wavelength, which enables Pdots-PPF ratiometric pH sensing ability. Förster resonance energy transfer (FRET) together with the use of PFBT amplify the FITC signal, which enables Pdots-PPF robust sensitivity to pH. The emission intensity ratio (I517/I439) of Pdots-PPF changes linearly as a function of pH within the range of pH 3.0 to 8.0. Pdots-PPF also possesses desirable reversibility and stability in pH measurement. More importantly, Pdots-PPF was successfully used for cell imaging in Hela cells, exhibiting effective cellular uptake and low cytotoxicity. Our study suggests the promising potential of Pdots-PPF as an in vivo biomarker.

scholarly journals Nanoparticle-Mediated Dual Targeting: An Approach for Enhanced Baicalin Delivery to the Liver

Pharmaceutics ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 107 ◽  
Author(s):  
Iman Saad Ahmed ◽  
Hassan Medhat Rashed ◽  
Hend Fayez ◽  
Faten Farouk ◽  
Rehab Nabil Shamma
Keyword(s):  
Oral Administration ◽  
Water Solubility ◽  
Area Under The Curve ◽  
Oral Solution ◽  
Water Soluble ◽  
Spherical Particles ◽  
Therapeutic Molecules ◽  
Ph Dependent ◽  
Full Factorial

In this study, water-soluble chitosan lactate (CL) was reacted with lactobionic acid (LA), a disaccharide with remarkable affinity to hepatic asialoglycoprotein (ASGP) receptors, to form dual liver-targeting LA-modified-CL polymer for site-specific drug delivery to the liver. The synthesized polymer was used to encapsulate baicalin (BA), a promising bioactive flavonoid with pH-dependent solubility, into ultrahigh drug-loaded nanoparticles (NPs) via the ionic gelation method. The successful chemical conjugation of LA with CL was tested and the formulated drug-loaded LA-modified-CL-NPs were assessed in terms of particle size (PS), encapsulation efficiency (EE) and zeta potential (ZP) using full factorial design. The in vivo biodistribution and pharmacokinetics of the designed NPs were assessed using 99mTc-radiolabeled BA following oral administration to mice and results were compared to 99mTc-BA-loaded-LA-free-NPs and 99mTc-BA solution as controls. Results showed that the chemical modification of CL with LA was successfully achieved and the method of preparation of the optimized NPs was very efficient in encapsulating BA into nearly spherical particles with an extremely high EE exceeding 90%. The optimized BA-loaded-LA-modified-CL-NPs showed an average PS of 490 nm, EE of 93.7% and ZP of 48.1 mV. Oral administration of 99mTc-BA-loaded-LA-modified-CL-NPs showed a remarkable increase in BA delivery to the liver over 99mTc-BA-loaded-LA-free-CL-NPs and 99mTc-BA oral solution. The mean area under the curve (AUC0–24) estimates from liver data were determined to be 11-fold and 26-fold higher from 99mTc-BA-loaded-LA-modified-CL-NPs relative to 99mTc-BA-loaded-LA-free-CL-NPs and 99mTc-BA solution respectively. In conclusion, the outcome of this study highlights the great potential of using LA-modified-CL-NPs for the ultrahigh encapsulation of therapeutic molecules with pH-dependent/poor water-solubility and for targeting the liver.

Solvent-controlled and solvent-dependent strategies for the synthesis of multicolor carbon dots for pH sensing and cell imaging

2019 ◽  
Vol 7 (31) ◽  
pp. 9709-9718 ◽  
Author(s):  
Jianliang Bai ◽  
Yusha Ma ◽  
Guojun Yuan ◽  
Xu Chen ◽  
Jing Mei ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Cell Imaging ◽  
Ph Sensing ◽  
Ph Dependent

Solvent-controlled, pH-dependent and solvent-dependent strategies are proposed to obtain multicolor carbon dots using the same precursor.

Synthesis, selective pH-sensing activity and logic behavior of highly water-soluble 1,8-naphthalimide and dihydroimidazonaphthalimide derivatives

2014 ◽  
Vol 149 ◽  
pp. 325-332 ◽  
Author(s):  
Nikolai I. Georgiev ◽  
Stefan M. Dimov ◽  
Abdullah M. Asiri ◽  
Khalid A. Alamry ◽  
Abdullah Y. Obaid ◽  
...  
Keyword(s):  
Water Soluble ◽  
Ph Sensing
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