Cellular Stress Assay in Peripheral Blood Mononuclear Cells: Factors Influencing Its Results.

Cellular stress is central to the understanding of pathological mechanisms and the development of new therapeutic strategies and serves as a biomarker for disease progression in neurodegeneration, diabetes, cancer, cardiovascular and other chronic diseases. The common cellular stress assay (CSA) based on Seahorse technology in peripheral blood mononuclear cells (PBMCs) shows inconsistent results, which prevents its use as a biomarker for the progression of chronic diseases. Therefore, the aim of this study was to investigate potential factors that affect the CSA in PBMCs.

Na Selective Fluorescent Tools Based on Fluorescence Intensity Enhancements, Lifetime Changes, and on a Ratiometric Response.

Over the years, we developed highly selective fluorescent probes for K in water, which show K -induced fluorescence intensity enhancements, lifetime changes, or a ratiometric behavior at two emission wavelengths (cf. Scheme 1, K1-K4). In this paper, we introduce selective fluorescent probes for Na in water, which also show Na induced signal changes, which are analyzed by diverse fluorescence techniques.

A Ratiometric Fluorescent Probe for K in Water Based on a Phenylaza-18-Crown-6 Lariat Ether.

This work presents two molecular fluorescent probes 1 and 2 for the selective determination of physiologically relevant K levels in water based on a highly K /Na selective building block, the o-(2-methoxyethoxy)phenylaza-18-crown-6 lariat ether unit. Fluorescent probe 1 showed a high K -induced fluorescence enhancement (FE) by a factor of 7.7 of the anthracenic emission and a dissociation constant (K ) value of 38 mm in water.

Highly K -Selective Fluorescent Probes for Lifetime Sensing of K in Living Cells.

The new K -selective fluorescent probes 1 and 2 were obtained by Cu -catalyzed 1,3-dipolar azide alkyne cycloaddition (CuAAC) reactions of an alkyne-substituted [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD) ester fluorophore with azido-functionalized N-phenylaza-18-crown-6 ether and N-(o-isopropoxy) phenylaza-18-crown-6 ether, respectively. Probes 1 and 2 allow the detection of K in the presence of Na in water by fluorescence enhancement (2.2 for 1 at 2000 mm K and 2.

Design of Na -Selective Fluorescent Probes: A Systematic Study of the Na -Complex Stability and the Na /K Selectivity in Acetonitrile and Water.

There is a tremendous demand for highly Na -selective fluoroionophores to monitor the top analyte Na in life science. Here, we report a systematic route to develop highly Na /K selective fluorescent probes. Thus, we synthesized a set of fluoroionophores 1, 3, 4, 5, 8 and 9 (see Scheme ) to investigate the Na /K selectivity and Na - complex stability in CH CN and H O.

A Highly K(+) -Selective Fluorescent Probe - Tuning the K(+) -Complex Stability and the K(+) /Na(+) Selectivity by Varying the Lariat-Alkoxy Unit of a Phenylaza[18]crown-6 Ionophore.

A desirable goal is to synthesize easily accessible and highly K(+) /Na(+) -selective fluoroionophores to monitor physiological K(+) levels in vitro and in vivo. Therefore, highly K(+) /Na(+) -selective ionophores have to be developed. Herein, we obtained in a sequence of only four synthetic steps a set of K(+) -responsive fluorescent probes 4, 5 and 6.

A Highly K(+)-Selective Two-Photon Fluorescent Probe.

A highly K(+)-selective two-photon fluorescent probe for the in vitro monitoring of physiological K(+) levels in the range of 1-100 mM is reported. The two-photon excited fluorescence (TPEF) probe shows a fluorescence enhancement (FE) by a factor of about three in the presence of 160 mM K(+), independently of one-photon (OP, 430 nm) or two-photon (TP, 860 nm) excitation and comparable K(+)-induced FEs in the presence of competitive Na(+) ions. The estimated dissociation constant (Kd ) values in Na(+)-free solutions (Kd (OP) =(28±5) mM and Kd (TP)=(36±6) mM) and in combined K(+)/Na(+) solutions (Kd (OP) =(38±8) mM and Kd (TP)=(46±25) mM) reflecting the high K(+)/Na(+) selectivity of the fluorescent probe.