Rational design of pH-responsive near-infrared spirocyclic cyanines: the effects of substituents and the external environment.

pH-responsive spirocyclic cyanine dyes were designed and synthesized. The equilibrium constant for cyclization (p) could be rationally controlled by changing the nucleophilic moiety and the side chains. Encapsulation in polymeric micelles inhibited the H-aggregation of the dye, and the p could be shifted according to the amphiphilic polymer employed.

Treatment with hepatocyte transplantation in a novel mouse model of persistent liver failure.

Background And Aim: Cell-based transplantation therapy using hepatocytes, hepatic stem cells, hepatocyte-like cells induced from stem cells, etc. is thought to be an attractive alternative to liver transplantation, and have been studied to date. For its clinical application, however, it is extremely important to develop a model that reproduces the pathological conditions with indication for treatment and enables the study for the ideal treatment strategy.

The Short-term Outcomes of Physiotherapy for Patients with Acetabular Labral Tears: An Analysis according to Severity of Injury in Magnetic Resonance Imaging.

Purpose: The aim of this study was to evaluate the short-term outcome of physiotherapy in patients with acetabular labral tears and to assess the effectiveness of physiotherapy according to the severity of the labral tear.

Materials And Methods: Thirty-five patients who underwent physiotherapy for treatment of symptomatic acetabular labral tears were enrolled. We evaluated the severity of the acetabular labral tears, which were classified based on the Czerny classification system using 3-T MRI.

A Series of Furimazine Derivatives for Sustained Live-Cell Bioluminescence Imaging and Application to the Monitoring of Myogenesis at the Single-Cell Level.

Bioluminescence (BL) imaging, which utilizes light emitted through the enzymatic reaction of luciferase oxidizing its substrate luciferin, enables sensitive and noninvasive monitoring of life phenomena. Herein, we developed a series of caged furimazine (FMZ) derivatives by introducing a protective group at the C-3 position and a hydroxy group at the C-6 phenyl ring to realize long-term live-cell BL imaging based on the NanoLuc (NLuc)/NanoKAZ (NKAZ)-FMZ system. The membrane permeability and cytotoxicity of the substrates were evaluated and related to their hydrophobicity.

Differential Effect of Azetidine Substitution in Firefly Luciferin Analogues.

Replacing an N,N-dimethylamino group in a classical fluorophore with a four membered azetidine ring provides an improved luminescence quantum yield. Herein, we extended this strategy to bioluminescent firefly luciferin analogues and evaluated its general validity. For this purpose, four types of luciferin cores were employed, and a total of eight analogues were evaluated.

Development of Near-Infrared Fluorescent Mg Probe and Application to Multicolor Imaging of Intracellular Signals.

Recent extensive studies revealed that the intracellular concentration of magnesium ions (Mg) is one of the important factors to regulate cellular functions. To evaluate the impact of Mg concentration changes on intracellular signals or events, simultaneous imaging of Mg with those phenomena is a powerful technique. The present protocol describes the synthesis and evaluation of near-infrared (NIR) fluorescent Mg-selective probes, named KMG-500 series, and the application to simultaneous imaging of the corresponding intracellular signal transductions and molecular events.

Quantitative Evaluation of Ankle Instability Using a Capacitance-Type Strain Sensor.

Background: Manual evaluation is an important method for assessing ankle instability, but it is not quantitative. Capacitance-type sensors can be used to measure the distance on the basis of the capacitance value. We applied the sensor to the noninvasive device for measuring ankle instability and showed its utility.

Long-term single cell bioluminescence imaging with C-3 position protected coelenterazine analogues.

Bioluminescence is a powerful imaging modality for monitoring biological phenomena both in vitro and in vivo. Bioluminescence imagin (BLI) is becoming a seamless imaging technology covering the range from cells to organs of small animals. Long-term imaging at the single cell level would lead to a true understanding of the dynamics of life phenomena.

Ring-Fused Firefly Luciferins: Expanded Palette of Near-Infrared Emitting Bioluminescent Substrates.

Firefly bioluminescence is broadly applied as a noninvasive imaging modality in the biomedical research field. One limitation in firefly bioluminescence imaging is the limited variety of luciferins emitting in the near-infrared (NIR) region (650-900 nm), where tissue penetration is high. Herein, we describe a series of structure-inherent NIR emitting firefly luciferin analogues, , designed through a ring fusion strategy.

Inkjet-printed pH-independent paper-based calcium sensor with fluorescence signal readout relying on a solvatochromic dye.

A challenge for paper-based cation sensors relying on classical carrier-based ion-selective optodes (ISOs) is their pH-cross response caused by the use of H-sensitive chromoionophores as optical signal transducers. This work demonstrates fully pH-independent fluorescence-based calcium detection with a paper-based plasticizer-free ISO. To achieve a pH-independent assay, a solvatochromic dye (SD) instead of a traditional H-sensitive chromoionophore has been applied to the paper-based ISO by means of inkjet printing technology.

Near-Infrared Fluorescent Probes for Imaging of Intracellular Mg and Application to Multi-Color Imaging of Mg, ATP, and Mitochondrial Membrane Potential.

The magnesium ion (Mg) is an essential cation to maintain proper cellular activities. To visualize the dynamics and functions of Mg, there is a great need for the development of Mg-selective fluorescent probes. However, conventional Mg fluorescent probes are falling behind in low selectivity and poor fluorescence color variation.

Inkjet-Printed Colorimetric Paper-Based Gas Sensor Arrays for the Discrimination of Volatile Primary Amines with Amine-Responsive Dye-Encapsulating Polymer Nanoparticles.

Arrays of gas sensors are of high interest for "electronic nose" applications. Here, we describe the fabrication of a colorimetric single-use gas sensor array made of paper allowing the discrimination of volatile primary amines based on their polarity. For this purpose, polymeric nanoparticles with different polarities containing an amine-sensitive chromogenic dye are deposited onto paper substrates by means of inkjet printing.

Effect of hip angle on neuromuscular activation of the adductor longus and adductor magnus muscles during isometric hip flexion and extension.

Purpose: Neuromuscular activation of the adductor longus (AL) and adductor magnus (AM) muscles at different hip flexion angles during hip flexion and extension has not been clarified. This study aimed to compare the relationship between hip flexion angle and the electromyogram of the AL muscle with that of the AM muscle during isometric hip flexion and extension.

Methods: Fifteen healthy young men were included in this study.

Near-Infrared Bioluminescence Imaging with a through-Bond Energy Transfer Cassette.

A coelenterazine (CTZ) analogue emitting near-infrared (NIR) bioluminescence was synthesized for through-bond energy transfer (TBET)-based imaging modalities. The analogue, named Cy5-CTZ, was prepared by conjugating cyanine-5 (Cy5) dye to CTZ through an acetylene linker. This novel derivative is intrinsically fluorescent and emits NIR-shifted luminescence upon reacting with an appropriate luciferase, the Renilla luciferase.

An allylated firefly luciferin analogue with luciferase specific response in living cells.

An allylated firefly luciferin was successfully synthesized and its bioluminescence properties were evaluated. When applied to cellular imaging in combination with Eluc, which is one of the commercially available luciferases, this analogue displayed a luciferase-specific bioluminescence signal with prolonged emission (>100 min).

Highly Sensitive Bioluminescent Probe for Thiol Detection in Living Cells.

The sensitive detection of thiols including glutathione and cysteine is desirable owing to their roles as indispensable biomolecules in maintaining intracellular biological redox homeostasis. Herein, we report the design and synthesis of SEluc-1 (sulfinate ester luciferin), a chemoselective probe exhibiting a ratiometric and turn-on response towards thiols selectively in fluorescence and bioluminescence, respectively. The probe, which was designed based on the "caged" luciferin strategy, displays excellent selectivity, high signal/noise ratio (>240 in the case of bioluminescence), and a biologically relevant limit of detection (LOD, 80 nm for cysteine), which are all desirable traits for a sensitive bioluminescent sensor.