scholarly journals Terbium(III)-thiacalix[4]arene nanosensor for highly sensitive intracellular monitoring of temperature changes within the 303–313 K range

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rustem R. Zairov ◽  
Alexey P. Dovzhenko ◽  
Anastasiia S. Sapunova ◽  
Alexandra D. Voloshina ◽  
Kirill A. Sarkanich ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Energy Gap ◽  
Narrow Range ◽  
Temperature Changes ◽  
Cell Internalization ◽  
Highly Sensitive ◽  
Low Cytotoxicity ◽  
Upper Rim ◽  
Back Energy Transfer

AbstractThe work introduces hydrophilic PSS-[Tb2(TCAn)2] nanoparticles to be applied as highly sensitive intracellular temperature nanosensors. The nanoparticles are synthesized by solvent-induced nanoprecipitation of [Tb2(TCAn)2] complexes (TCAn - thiacalix[4]arenes bearing different upper-rim substituents: unsubstituted TCA1, tert-buthyl-substituted TCA2, di- and tetra-brominated TCA3 and TCA4) with the use of polystyrenesulfonate (PSS) as stabilizer. The temperature responsive luminescence behavior of PSS-[Tb2(TCAn)2] within 293–333 K range in water is modulated by reversible changes derived from the back energy transfer from metal to ligand (M* → T1) correlating with the energy gap between the triplet levels of ligands and resonant 5D4 level of Tb3+ ion. The lowering of the triplet level (T1) energies going from TCA1 and TCA2 to their brominated counterparts TCA3 and TCA4 facilitates the back energy transfer. The highest ever reported temperature sensitivity for intracellular temperature nanosensors is obtained for PSS-[Tb2(TCA4)2] (SI = 5.25% K−1), while PSS-[Tb2(TCA3)2] is characterized by a moderate one (SI = 2.96% K−1). The insignificant release of toxic Tb3+ ions from PSS-[Tb2(TCAn)2] within heating/cooling cycle and the low cytotoxicity of the colloids point to their applicability in intracellular temperature monitoring. The cell internalization of PSS-[Tb2(TCAn)2] (n = 3, 4) marks the cell cytoplasm by green Tb3+-luminescence, which exhibits detectable quenching when the cell samples are heated from 303 to 313 K. The colloids hold unprecedented potential for in vivo intracellular monitoring of temperature changes induced by hyperthermia or pathological processes in narrow range of physiological temperatures.

Detecting and imaging of SO2 derivatives in living cells with zero cross-talk colorimetric mitochondria-targeted fluorescent probe

2020 ◽  
Vol 98 (1) ◽  
pp. 1-6
Author(s):  
Dan Wu ◽  
Shiqi Rong ◽  
Yi Liu ◽  
Fei Zheng ◽  
Yankun Zhao ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Talk ◽  
High Sensitivity ◽  
Living Cells ◽  
High Resolution Imaging ◽  
Biochemical Processes ◽  
Highly Sensitive ◽  
Resolution Imaging ◽  
Low Cytotoxicity

It is well known that excessive levels of sulfur dioxide and its derivatives are connected to diverse diseases. Therefore, developing highly sensitive probes to detect and monitor sulfite in living cells is important for the diagnosis of disease and the study of biochemical processes in vivo. In this report, two zero cross-talk ratiometric fluorescent probes were synthesized (CA-ID-MC and CA-BI-MC), which were derived from carbazole-indolenine π-conjugated system for effective detection of sulfite in living cells. Observably, CA-BI-MC exhibited the largest emission shift of 157 nm from 617 to 460 nm with the addition of various concentrations of sulfite, which is beneficial for high-resolution imaging of the sulfite. CA-BI-MC also exhibits high sensitivity and low cytotoxicity. More importantly, this probe successfully located mitochondria and sensed the sulfite in HeLa cells caused by exogenous stimulation.

Synthesis and 31 P NMR characterization of new low toxic highly sensitive pH probes designed for in vivo acidic pH studies

2002 ◽  
Vol 10 (5) ◽  
pp. 1451-1458 ◽  
Author(s):  
Sophie Martel ◽  
Jean-Louis Clément ◽  
Agnès Muller ◽  
Marcel Culcasi ◽  
Sylvia Pietri
Keyword(s):  
Acidic Ph ◽  
Highly Sensitive ◽  
Nmr Characterization ◽  
Low Toxic ◽  
Ph Probes

scholarly journals Antimicrobial Activity of Curcumin in Nanoformulations: A Comprehensive Review

2021 ◽  
Vol 22 (13) ◽  
pp. 7130
Author(s):  
Jeffersson Krishan Trigo-Gutierrez ◽  
Yuliana Vega-Chacón ◽  
Amanda Brandão Soares ◽  
Ewerton Garcia de Oliveira Mima
Keyword(s):  
Polymeric Nanoparticles ◽  
Graphene Quantum Dots ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Clinical Scenarios ◽  
Low Cytotoxicity ◽  
Bacteria And Fungi ◽  
Drug Resistant Strains

Curcumin (CUR) is a natural substance extracted from turmeric that has antimicrobial properties. Due to its ability to absorb light in the blue spectrum, CUR is also used as a photosensitizer (PS) in antimicrobial Photodynamic Therapy (aPDT). However, CUR is hydrophobic, unstable in solutions, and has low bioavailability, which hinders its clinical use. To circumvent these drawbacks, drug delivery systems (DDSs) have been used. In this review, we summarize the DDSs used to carry CUR and their antimicrobial effect against viruses, bacteria, and fungi, including drug-resistant strains and emergent pathogens such as SARS-CoV-2. The reviewed DDSs include colloidal (micelles, liposomes, nanoemulsions, cyclodextrins, chitosan, and other polymeric nanoparticles), metallic, and mesoporous particles, as well as graphene, quantum dots, and hybrid nanosystems such as films and hydrogels. Free (non-encapsulated) CUR and CUR loaded in DDSs have a broad-spectrum antimicrobial action when used alone or as a PS in aPDT. They also show low cytotoxicity, in vivo biocompatibility, and improved wound healing. Although there are several in vitro and some in vivo investigations describing the nanotechnological aspects and the potential antimicrobial application of CUR-loaded DDSs, clinical trials are not reported and further studies should translate this evidence to the clinical scenarios of infections.

Optically pumped magnetometers enable a new level of biomagnetic measurements

2020 ◽  
Vol 9 (5) ◽  
pp. 247-251
Author(s):  
Tilmann Sander ◽  
Anna Jodko-Władzińska ◽  
Stefan Hartwig ◽  
Rüdiger Brühl ◽  
Thomas Middelmann
Keyword(s):  
Quantum Interference ◽  
High Sensitivity ◽  
High Temporal Resolution ◽  
Optically Pumped ◽  
New Class ◽  
Magnetic Shields ◽  
Highly Sensitive ◽  
Electric And Magnetic Fields ◽  
Auditory Evoked Fields

AbstractThe electrophysiological activities in the human body generate electric and magnetic fields that can be measured noninvasively by electrodes on the skin, or even, not requiring any contact, by magnetometers. This includes the measurement of electrical activity of brain, heart, muscles and nerves that can be measured in vivo and allows to analyze functional processes with high temporal resolution. To measure these extremely small magnetic biosignals, traditionally highly sensitive superconducting quantum-interference devices have been used, together with advanced magnetic shields. Recently, they have been complemented in usability by a new class of sensors, optically pumped magnetometers (OPMs). These quantum sensors offer a high sensitivity without requiring cryogenic temperatures, allowing the design of small and flexible sensors for clinical applications. In this letter, we describe the advantages of these upcoming OPMs in two exemplary applications that were recently carried out at Physikalisch-Technische Bundesanstalt (PTB): (1) magnetocardiography (MCG) recorded during exercise and (2) auditory-evoked fields registered by magnetoencephalography.

Photon upconversion in multicomponent systems: Role of back energy transfer

2020 ◽  
Vol 153 (11) ◽  
pp. 114302
Author(s):  
Diletta Meroni ◽  
Angelo Monguzzi ◽  
Francesco Meinardi
Keyword(s):  
Energy Transfer ◽  
Multicomponent Systems ◽  
Back Energy Transfer

scholarly journals Real-Time In Vivo Bioluminescent Imaging for Evaluating the Efficacy of Antibiotics in a Rat Staphylococcus aureus Endocarditis Model

2005 ◽  
Vol 49 (1) ◽  
pp. 380-387 ◽  
Author(s):  
Yan Q. Xiong ◽  
Julie Willard ◽  
Jagath L. Kadurugamuwa ◽  
Jun Yu ◽  
Kevin P. Francis ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Imaging System ◽  
Bioluminescent Imaging ◽  
Vancomycin Therapy ◽  
Treatment Groups ◽  
Highly Sensitive ◽  
Relevant Animal Model ◽  
And Control

ABSTRACT Therapeutic options for invasive Staphylococcus aureus infections have become limited due to rising antimicrobial resistance, making relevant animal model testing of new candidate agents more crucial than ever. In the present studies, a rat model of aortic infective endocarditis (IE) caused by a bioluminescently engineered, biofilm-positive S. aureus strain was used to evaluate real-time antibiotic efficacy directly. This strain was vancomycin and cefazolin susceptible but gentamicin resistant. Bioluminescence was detected and quantified daily in antibiotic-treated and control animals with IE, using a highly sensitive in vivo imaging system (IVIS). Persistent and increasing cardiac bioluminescent signals (BLS) were observed in untreated animals. Three days of vancomycin therapy caused significant reductions in both cardiac BLS (>10-fold versus control) and S. aureus densities in cardiac vegetations (P < 0.005 versus control). However, 3 days after discontinuation of vancomycin therapy, a greater than threefold increase in cardiac BLS was observed, indicating relapsing IE (which was confirmed by quantitative culture). Cefazolin resulted in modest decreases in cardiac BLS and bacterial densities. These microbiologic and cardiac BLS differences during therapy correlated with a longer time-above-MIC for vancomycin (>12 h) than for cefazolin (∼4 h). Gentamicin caused neither a reduction in cardiac S. aureus densities nor a reduction in BLS. There were significant correlations between cardiac BLS and S. aureus densities in vegetations in all treatment groups. These data suggest that bioluminescent imaging provides a substantial advance in the real-time monitoring of the efficacy of therapy of invasive S. aureus infections in live animals.

scholarly journals Measuring ligand-dependent and ligand-independent interactions between nuclear receptors and associated proteins using Bioluminescence Resonance Energy Transfer (BRET2)

2006 ◽  
Vol 4 (1) ◽  
pp. nrs.04021 ◽  
Author(s):  
Kristen L. Koterba ◽  
Brian G. Rowan
Keyword(s):  
Energy Transfer ◽  
Protein Interactions ◽  
Fusion Proteins ◽  
Fluorescent Protein ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Renilla Luciferase ◽  
Receptor Protein ◽  
Protein Protein Interactions

Bioluminescent resonance energy transfer (BRET2) is a recently developed technology for the measurement of protein-protein interactions in a live, cell-based system. BRET2 is characterized by the efficient transfer of excited energy between a bioluminescent donor molecule (Renilla luciferase) and a fluorescent acceptor molecule (a mutant of Green Fluorescent Protein (GFP2)). The BRET2 assay offers advantages over fluorescence resonance energy transfer (FRET) because it does not require an external light source thereby eliminating problems of photobleaching and autoflourescence. The absence of contamination by light results in low background that permits detection of very small changes in the BRET2 signal. BRET2 is dependent on the orientation and distance between two fusion proteins and therefore requires extensive preliminary standardization experiments to conclude a positive BRET2 signal independent of variations in protein titrations and arrangement in tertiary structures. Estrogen receptor (ER) signaling is modulated by steroid receptor coactivator 1 (SRC-1). To establish BRET2 in a ligand inducible system we used SRC-1 as the donor moiety and ER as the acceptor moiety. Expression and functionality of the fusion proteins were assessed by transient transfection in HEK-293 cells followed by Western blot analysis and measurement of ER-dependent reporter gene activity. These preliminary determinations are required prior to measuring nuclear receptor protein-protein interactions by BRET2. This article describes in detail the BRET2 methodology for measuring interaction between full-length ER and coregulator proteins in real-time, in an in vivo environment.

scholarly journals Simulation and Analysis of Highly Sensitive MEMS Cantilever Designs for “in vivo Label Free” Biosensing

2014 ◽  
Vol 14 ◽  
pp. 85-92 ◽  
Author(s):  
Deep Kishore Parsediya ◽  
Jawar Singh ◽  
Pavan Kumar Kankar
Keyword(s):  
Label Free ◽  
Highly Sensitive

scholarly journals Selective treatment and monitoring of disseminated cancer micrometastases in vivo using dual-function, activatable immunoconjugates

2014 ◽  
Vol 111 (10) ◽  
pp. E933-E942 ◽  
Author(s):  
Bryan Q. Spring ◽  
Adnan O. Abu-Yousif ◽  
Akilan Palanisami ◽  
Imran Rizvi ◽  
Xiang Zheng ◽  
...  
Keyword(s):  
Cancer Cell ◽  
Near Infrared ◽  
Dual Function ◽  
Imaging Method ◽  
Drug Resistant ◽  
Micrometastatic Disease ◽  
Selective Treatment ◽  
Cell Internalization ◽  
Occult Disease

Drug-resistant micrometastases that escape standard therapies often go undetected until the emergence of lethal recurrent disease. Here, we show that it is possible to treat microscopic tumors selectively using an activatable immunoconjugate. The immunoconjugate is composed of self-quenching, near-infrared chromophores loaded onto a cancer cell-targeting antibody. Chromophore phototoxicity and fluorescence are activated by lysosomal proteolysis, and light, after cancer cell internalization, enabling tumor-confined photocytotoxicity and resolution of individual micrometastases. This unique approach not only introduces a therapeutic strategy to help destroy residual drug-resistant cells but also provides a sensitive imaging method to monitor micrometastatic disease in common sites of recurrence. Using fluorescence microendoscopy to monitor immunoconjugate activation and micrometastatic disease, we demonstrate these concepts of “tumor-targeted, activatable photoimmunotherapy” in a mouse model of peritoneal carcinomatosis. By introducing targeted activation to enhance tumor selectively in complex anatomical sites, this study offers prospects for catching early recurrent micrometastases and for treating occult disease.

Role of ion transfer processes in acid-base regulation with temperature changes in fish

1984 ◽  
Vol 246 (4) ◽  
pp. R441-R451 ◽  
Author(s):  
N. Heisler
Keyword(s):  
Ion Transfer ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Fish Tissues ◽  
Model Calculations ◽  
Temperature Changes ◽  
Transfer Processes ◽  
Transfer Mechanisms

The contributions of transmembrane and transepithelial ion transfer processes and of nonbicarbonate buffering to the in vivo acid-base regulation have been evaluated. Model calculations were performed utilizing experimental data on transepithelial transfer of ions relevant for the acid-base regulation, the intracellular buffering properties of fish tissues, and the behavior of intracellular and extracellular pH and bicarbonate concentration with changes of temperature. The results of these studies indicate that the changes in the pK values of physiological nonbicarbonate buffers with changes in temperature support the adjustment of pH to lower values with rising temperature; however, transmembrane and transepithelial ion transfer mechanisms determine the acid-base regulation of intracellular and extracellular compartments.

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