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Covalent organic frameworks (COFs) with ordered π structures are very promising in porous light‐emitting materials. However, most of these COFs are either poor in luminescence or lack of water‐stability. Herein, a series of isostructural D−A vinylene‐linked COFs were constructed based a new D2h symmetric linker 1,4‐bis(4,6‐dimethyl‐1,3,5‐triazin‐2‐yl)benzene (TMTA) with high crystallinity, comparative high surface area and excellent chemical/thermal stability. Impressively, their adsorption and luminescence wavelength vary with respect to the density of π‐systems in the electron‐donating group, which constitute the foundation for molecular engineering the luminescent properties of vinylene‐linked COFs. The DFT calculations further established the relationship between the luminescence properties and the donor electronic structure. Moreover, one of representative COF named FZU‐203 showed inspiring applications in bioimaging, which may further provide strategic guidance for the use of vinylene‐linked COFs as fluorescent nanoprobes in non‐invasive medical diagnosis and visualization therapy of tumors. [ABSTRACT FROM AUTHOR]

To fill the need for environmentally sensitive fluorescent unnatural amino acids able to operate in the red region of the spectrum, we have designed and synthesized Alared, a red solvatochromic and fluorogenic amino acid derived from the Nile Red chromophore. The new unnatural amino acid can be easily integrated into bioactive peptides using classical solid‐phase peptide synthesis. The fluorescence quantum yield and the emission maximum of Alared‐labeled peptides vary in a broad range depending on the peptide's environment, making Alared a powerful reporter of biomolecular interactions. Due to its red‐shifted absorption and emission spectra, Alared‐labeled peptides could be followed in living cells with minimal interference from cellular autofluorescence. Using ratiometric fluorescence microscopy, we were able to track the fate of the Alared‐labeled peptide agonists of the apelin G protein‐coupled receptor upon receptor activation and internalization. Due to its color‐shifting environmentally sensitive emission, Alared allowed for distinguishing the fractions of peptides that are specifically bound to the receptor or unspecifically bound to different cellular membranes. [ABSTRACT FROM AUTHOR]

Polymorphism‐dependent cytotoxicity and cellular uptake of drug molecules have been studied for the past two decades. However, the visualization of polymorph‐dependent cellular uptake and cytotoxicity using microscopy imaging techniques has not yet been reported. The luminescent polymorph is an ideal candidate to validate the above hypothesis. Herein, we report the polymorph‐dependent cellular uptake, cytotoxicity, and bio‐imaging functions of polymorphs 1Y and 1R of a naphthalimide‐phenothiazine dyad. These polymorphs show different luminescence colors in the solid state and exhibit aggregation‐induced enhanced emission (AIEE) in the DMSO‐Water mixture. Bioimaging, cytotoxicity assay, and fluorescence‐activated cell sorting (FACS) studies revealed that these polymorphs show different levels of cytotoxicity, cellular uptake, localization, and imaging potential. Detailed photophysical, morphological, and biological studies revealed that the difference in molecular conformation in these polymorphs enables them to form aggregates of different sizes and morphology, which leads to the differential uptake of these into the cells and consequently shows different cytotoxicity and imaging potentials. [ABSTRACT FROM AUTHOR]

Discovering new modifications for oligonucleotide therapeutics is essential for expanding its application to new targets and diseases. In this project, we focus on conjugating metaled ligands to short interfering RNAs (siRNAs) to investigate robust and simple conjugation methods for adding new properties such as real‐time imaging to the siRNA. Here we report the chemical synthesis of novel Ga‐(III)‐corroles for their direct conjugation to siRNAs. Ga‐(III)‐corrole‐siRNAs showed promising results when evaluated for gene silencing and live cell imaging. The knockdown activity of the firefly luciferase reporter gene was measured to evaluate gene silencing activity. Gene silencing studies from two 5'‐Ga‐(III)‐labeled‐siRNAs exhibited dose‐dependent knockdown with IC50s of 812.7 and 451.4 pM, which is comparable to wild‐type (IC50=439.7 pM) in the absence of red light, and IC50s of 562.9 and 354.5 pM, which is also comparable to wild‐type (IC50=337.4 pM), in the presence of red light. In addition, imaging studies with Ga‐(III)‐corrole‐modified siRNAs showed intense fluorescence in HeLa cells, highlighting that the Ga‐(III)‐corrole modification is an effective fluorophore for siRNA tracing and imaging. Moreover, the photodynamic activity of free base corrole vs the Ga‐(III)‐corrole was evaluated. Results show an increase of light cytotoxicity of the corrole ligand upon the addition of Ga‐(III); however, no phototoxicity was observed when Ga‐(III) ligands were linked to siRNA. In conclusion, Ga‐(III)‐corrole‐siRNAs show promising results for applications in simultaneous real‐time imaging and gene silencing. [ABSTRACT FROM AUTHOR]

Organic and polymer fluorescent nanomaterials are a frontier research focus. Here in this work, a series of fluorinated zwitterionic random copolymers end‐attached with a quasi‐chromophoric group of pyrene or tetraphenylethylene (TPE) are well synthesized via atom transfer radical polymerization with activators regenerated by electron transfer (ARGET ATRP). Those random copolymers with total degree of polymerization 100 or 200 are able to produce fluorescent single‐chain nanoparticles (SCNPs) through intra‐chain self‐folding assembly with quite uniform diameters in the range of 10–20 nm as characterized by dynamic light scattering and transmission electron microscopy. By virtue of the segregation or confinement effect, both SCNPs functionalized with pyrene or TPE group are capable of emitting fluorescence, with pyrene tethered SCNPs exhibiting stronger fluorescence emission reaching the highest quantum yield ≈20%. Moreover, such kind of fluorescent SCNPs manifest low cytotoxicity and good cell imaging performance for Hela cells. The creation of fluorescent SCNPs through covalently attached one quasi‐chromophore to the end of one fluorinated zwitterionic random copolymer provides an alternative strategy for preparing polymeric luminescence nanomaterials, promisingly serving as a new type of fluorescent nanoprobes for biological imaging applications. [ABSTRACT FROM AUTHOR]

SUMMARY: Capturing images of the nuclear dynamics within live cells is an essential technique for comprehending the intricate biological processes inherent to plant cell nuclei. While various methods exist for imaging nuclei, including combining fluorescent proteins and dyes with microscopy, there is a dearth of commercially available dyes for live‐cell imaging. In Arabidopsis thaliana, we discovered that nuclei emit autofluorescence in the near‐infrared (NIR) range of the spectrum and devised a non‐invasive technique for the visualization of live cell nuclei using this inherent NIR autofluorescence. Our studies demonstrated the capability of the NIR imaging technique to visualize the dynamic behavior of nuclei within primary roots, root hairs, and pollen tubes, which are tissues that harbor a limited number of other organelles displaying autofluorescence. We further demonstrated the applicability of NIR autofluorescence imaging in various other tissues by incorporating fluorescence lifetime imaging techniques. Nuclear autofluorescence was also detected across a wide range of plant species, enabling analyses without the need for transformation. The nuclear autofluorescence in the NIR wavelength range was not observed in animal or yeast cells. Genetic analysis revealed that this autofluorescence was caused by the phytochrome protein. Our studies demonstrated that nuclear autofluorescence imaging can be effectively employed not only in model plants but also for studying nuclei in non‐model plant species. [ABSTRACT FROM AUTHOR]

SUMMARY: Plant cell walls are essential for defining plant growth and development, providing structural support to the main body and responding to abiotic and biotic cues. Cellulose, the main structural polymer of plant cell walls, is synthesized at the plasma membrane by cellulose synthase complexes (CSCs). The construction and transport of CSCs to and from the plasma membrane is poorly understood but is known to rely on the coordinated activity of cellulose synthase‐interactive protein 1 (CSI1), a key regulator of CSC trafficking. In this study, we found that Trs85, a TRAPPIII complex subunit, interacted with CSI1 in vitro. Using functional genetics and live‐cell imaging, we have shown that trs85‐1 mutants have reduced cellulose content, stimulated CSC delivery, an increased population of static CSCs and deficient clathrin‐mediated endocytosis in the primary cell wall. Overall, our findings suggest that Trs85 has a dual role in the trafficking of CSCs, by negatively regulating the exocytosis and clathrin‐mediated endocytosis of CSCs. Significance Statement: The synthesis of cellulose requires the transportation of cellulose synthase complexes (CSCs) to and from the plasma membrane. Our study has identified that Trs85, a TRAPPIII subunit, is important in both the delivery and endocytosis of CSCs at the plasma membrane in Arabidopsis. [ABSTRACT FROM AUTHOR]

SUMMARY: Confocal microscopy has greatly aided our understanding of the major cellular processes and trafficking pathways responsible for plant growth and development. However, a drawback of these studies is that they often rely on the manual analysis of a vast number of images, which is time‐consuming, error‐prone, and subject to bias. To overcome these limitations, we developed Dot Scanner, a Python program for analyzing the densities, lifetimes, and displacements of fluorescently tagged particles in an unbiased, automated, and efficient manner. Dot Scanner was validated by performing side‐by‐side analysis in Fiji‐ImageJ of particles involved in cellulose biosynthesis. We found that the particle densities and lifetimes were comparable in both Dot Scanner and Fiji‐ImageJ, verifying the accuracy of Dot Scanner. Dot Scanner largely outperforms Fiji‐ImageJ, since it suffers far less selection bias when calculating particle lifetimes and is much more efficient at distinguishing between weak signals and background signal caused by bleaching. Not only does Dot Scanner obtain much more robust results, but it is a highly efficient program, since it automates much of the analyses, shortening workflow durations from weeks to minutes. This free and accessible program will be a highly advantageous tool for analyzing live‐cell imaging in plants. Significance Statement: Live‐cell imaging analyses of fluorescently tagged particles in biological systems often require significant manual input that is time‐consuming and subject to bias. We have developed a free Python program, Dot Scanner, to allow users without any programming experience to analyze large datasets rapidly, efficiently, and with reduced bias. [ABSTRACT FROM AUTHOR]

In recent years, near‐infrared quantum dots (NIR QDs) have emerged as a promising candidate for biological imaging owing to their strong fluorescence penetrating into biological tissues and high imaging signal‐to‐noise ratio. Among various materials, InP QDs are environmentally friendly and have a relatively narrow bandgap of 1.35 eV, which provides a possibility for their emission wavelength to extend to the near‐infrared region. However, the strong reactivity of the precursor of phosphorus makes it challenging to synthesize NIR InP QDs, as it leads to rapid nucleation of the InP core. Herein, a method of epitaxial growth is reported to synthesize NIR InP QDs. Through high‐temperature nucleation and low‐temperature epitaxial growth, NIR InP QDs larger than 15 nm in size and with an emission wavelength of 807 nm are successfully synthesized. Furthermore, by removing InPOx defects on the surface of the core through HF etching, the quantum yield (QY) is increased from 6% to 12%. Ligand exchange successfully converted oil‐soluble ligands into water‐soluble ones, leading to excellent performance in cell imaging. The study provides a promising approach to the synthesis of desirable NIR InP QDs for use in biomedical imaging applications. [ABSTRACT FROM AUTHOR]

Most animal cell types are classified as non‐excitable because they do not generate action potentials observed in excitable cells, such as neurons and muscle cells. Thus, resolving voltage signals in non‐excitable cells demands sensors with exceptionally high voltage sensitivity. In this study, the ultrabright, ultrasensitive, and calibratable genetically encoded voltage sensor rEstus is developed using structure‐guided engineering. rEstus is most sensitive in the resting voltage range of non‐excitable cells and offers a 3.6‐fold improvement in brightness change for fast voltage spikes over its precursor ASAP3. Using rEstus, it is uncovered that the membrane voltage in several non‐excitable cell lines (A375, HEK293T, MCF7) undergoes spontaneous endogenous alterations on a second to millisecond timescale. Correlation analysis of these optically recorded voltage alterations provides a direct, real‐time readout of electrical cell–cell coupling, showing that visually connected A375 and HEK293T cells are also largely electrically connected, while MCF7 cells are only weakly coupled. The presented work provides enhanced tools and methods for non‐invasive voltage imaging in living cells and demonstrates that spontaneous endogenous membrane voltage alterations are not limited to excitable cells but also occur in a variety of non‐excitable cell types. [ABSTRACT FROM AUTHOR]

Controlling the efficient emission of organic luminogens in both monomeric and various aggregated states remains a challenging task. In this work, the motion of an organic luminophores is synergistically regulated by introducing side alkyl chains with appropriate length and the aromatic rotor triphenylamine. This study finds that the incorporation of alkyl chains not only increased the rotational barriers in the molecule, but also influenced the packing modes. The as‐prepared organic luminogen, FIMPA‐C6, exhibited bright emissions in solution, polymorph, and amorphous states. Furthermore, the emission of FIMPA‐C6 can be widely tuned from yellow to deep red in different aggregated states. The exceptional luminescent properties of FIMPA‐C6 make it a promising functional dye for cellular imaging applications. [ABSTRACT FROM AUTHOR]

Synthesis and photophysical properties of a fluorescent probe HBD is described. Probe upon interaction with metal ions, anions and nucleoside pyrophosphates (NPPs) showed fluorescence quenching with Cu2+ due to chelation enhanced quenching effect (CHEQ). Moreover, interaction of ensemble HBD.Cu2+ with anions and NPPs showed fluorescence “turn‐On” response with ATP selectively. “On‐Off‐On” responses observed with Cu2+ and ATP is attributed to an interplay between ESIPT and TICT processes. Cyclic voltammogram of probe exhibited quasi‐reversible redox behaviour with three oxidation and two reduction potentials and the change in band gaps of probe suggested the interaction with Cu2+ and ATP. The 2 : 1 and 1 : 1 binding stoichiometry for an interaction between probe and Cu2+ (LOD, 62 nM) and ensemble, HBD.Cu2+ with ATP (LOD, 0.4 μM) respectively are realised by Job's plot and HRMS data. Cell imaging studies carried out to detect Cu2+ and ATP in HeLa cells. Also, the output emission observed with Cu2+ and ATP is utilized to construct an implication (IMP) logic gate. Test paper strips showed naked‐eye visible color responses to detect Cu2+ and ATP. In real water samples probe successfully detected copper (0.03 μM) between 5–6.5 ppb level (ICP‐MS method). [ABSTRACT FROM AUTHOR]

Many clinical procedures and biomedical research workflows rely on microscopy, including diagnosis of cancer, genetic disorders, autoimmune diseases, infections, and quantification of cell culture. Despite its widespread use, traditional image acquisition and review by trained microscopists is often lengthy and expensive, limited to large hospitals or laboratories, precluding use in point‐of‐care settings. In contrast, lensless or lensfree holographic microscopy (LHM) is inexpensive and widely deployable because it can achieve performance comparable to expensive and bulky objective‐based benchtop microscopes while relying on components that cost only a few hundred dollars or less. Lab‐on‐a‐chip integration is practical and enables LHM to be combined with single‐cell isolation, sample mixing, and in‐incubator imaging. Additionally, many manual tasks in conventional microscopy are instead computational in LHM, including image focusing, stitching, and classification. Furthermore, LHM offers a field of view hundreds of times greater than that of conventional microscopy without sacrificing resolution. Here, the basic LHM principles are summarized, as well as recent advances in artificial intelligence integration and enhanced resolution. How LHM is applied to the above clinical and biomedical applications is discussed in detail. Finally, emerging clinical applications, high‐impact areas for future research, and some current challenges facing widespread adoption are identified. [ABSTRACT FROM AUTHOR]

The deployment of small‐molecule fluorescent agents plays an ever‐growing role in medicine and drug development. Herein, we complement the portfolio of powerful fluorophores, reporting the serendipitous discovery and development of a novel class with an imidazo[1,2‐a]pyridinium triflate core, which we term PyrAtes. These fluorophores are synthesized in a single step from readily available materials (>60 examples) and display Stokes shifts as large as 240 nm, while also reaching NIR−I emissions at λmax as long as 720 nm. Computational studies allow the development of a platform for the prediction of λmax and λEm. Furthermore, we demonstrate the compatibility of these novel fluorophores with live cell imaging in HEK293 cells, suggesting PyrAtes as potent intracellular markers. [ABSTRACT FROM AUTHOR]

Anthracene carboximides (ACIs) conjugated with gluco‐, galacto‐ and mannopyranosides are synthesized, by glycosylation of N‐hydroxyethylanthracene carboximide acceptor with glycosyl donors. Glycoconjugation of anthracene carboximide increases the aq. solubility by more than 3‐fold. The glycoconjugates display red‐shifted absorption and emission, as compared to anthracene. Large Stokes shift (λabs/λem=445/525 nm) and high fluorescence quantum yields (Φ) of 0.86 and 0.5 occur in THF and water, respectively. The ACI‐glycosides undergo facile photodimerization in aqueous solutions, leading to the formation of the head‐to‐tail dimer, as a mixture of syn and anti‐isomers. Solution phase and solid‐state characterizations by dynamic light scattering (DLS), microscopic imaging by atomic force (AFM) and transmission electron (TEM) microscopies reveal self‐assembled vesicle structures of ACI glycosides. These self‐assembled structures act as multivalent glycoclusters for ligand‐specific lectin binding, as evidenced by the binding of Man‐ACI to Con A, by fluorescence and turbidity assays. The conjugates do not show cellular cytotoxicity (IC50) till concentrations of 50 μM with HeLa and HepG2 cell lines and are cell‐permeable, showing strong fluorescence inside the cells. These properties enable the glycoconjugates to be used in cell imaging. The non‐selective cellular uptake of the glycoconjugates suggests a passive diffusion through the membrane. [ABSTRACT FROM AUTHOR]

Molecular beacons (MBs) have been used on surfaces for detecting oligonucleotides. Attempts to use them intracellularly for monitoring mRNA content have been made, however, without any clear conclusion regarding the reliability of the method, mainly due to false positive signals. To reach an understanding of the intracellular fate of MBs, a critical question remains: how long after MB delivery and where in the cell does a false positive signal appear? To answer that question, the MB delivery method should allow for a time‐stamped synchronized delivery of MBs to multiple cells, resulting in MBs being distributed in the cytosol immediately after delivery. Herein, nanostraws are used to inject MBs targeting insulin (Ins1) mRNA directly in the cytosol of clonal beta‐cells, and the evolution of the MB fluorescence in time and space is monitored. The results show an MB translocation to the nucleus, where MBs are degraded or where they open nonspecifically, before the fluorophore alone is expelled back from the nucleus to the cytosol. The signal translocation to the nucleus and back to the cytosol is faster when scrambled MBs are used. The results shed light on the intracellular fate of MBs and highlight the short time scales before false positive signals become predominant. [ABSTRACT FROM AUTHOR]

Fluorescence microscopy is a powerful tool used in scientific and medical research, but it is inextricably linked to phototoxicity. Neglecting phototoxicity can lead to erroneous or inconclusive results. Recently, several reports have addressed this issue, but it is still underestimated by many researchers, even though it can lead to cell death. Phototoxicity can be reduced by appropriate microscopic techniques and carefully designed experiments. This review focuses on recent strategies to reduce phototoxicity in microscopic imaging of living cells and tissues. We describe digital image processing and new hardware solutions. We point out new modifications of microscopy methods and hope that this review will interest microscopy hardware engineers. Our aim is to underscore the challenges and potential solutions integral to the design of microscopy systems. Simultaneously, we intend to engage biologists, offering insight into the latest technological advancements in imaging that can enhance their understanding and practice. [ABSTRACT FROM AUTHOR]

High‐resolution spatio‐temporal monitoring of the cell membrane lipid order provides visual insights into the complex and sophisticated systems that control cellular physiological functions. Solvatochromic fluorescent probes are highly promising noninvasive visualization tools for identifying the ordering of the microenvironment of plasma membrane microdomains. However, conventional probes, although capable of structural analysis, lack the necessary long‐term photostability required for live imaging at the cellular level. Here, an ultra‐high‐light‐resistant solvatochromic fluorescence probe, 2‐N,N‐diethylamino‐7‐(4‐methoxycarbonylphenyl)‐9,9‐dimethylfluorene (FπCM) is reported, which enables live lipid order imaging of cell division. This probe and its derivatives exhibit sufficient fluorescence wavelengths, brightness, polarity responsiveness, low phototoxicity, and remarkable photostability under physiological conditions compared to conventional solvatochromic probes. Therefore, these probes have the potential to overcome the limitations of fluorescence microscopy, particularly those associated with photobleaching. FπCM probes can serve as valuable tools for elucidating mechanisms of cellular processes at the bio‐membrane level. [ABSTRACT FROM AUTHOR]

In this study, a novel, high content technique using a cylindrical acoustic transducer, stroboscopic fast imaging, and homodyne detection to recover the mechanical properties (dynamic shear modulus) of living adherent cells at low ultrasonic frequencies is presented. By analyzing the micro‐oscillations of cells, whole populations are simultaneously mechanotyped with sub‐cellular resolution. The technique can be combined with standard fluorescence imaging allowing to further cross‐correlate biological and mechanical information. The potential of the technique is demonstrated by mechanotyping co‐cultures of different cell types with significantly different mechanical properties. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Autophagy is a multi‐step cell metabolism process in which cells remove damaged and unwanted materials. During autophagy, autophagosomes fuse with lysosomes to form autophagosomes. Autophagosomal membrane components are recycled from autolysosomes through the autophagosomal components recycling (ACR), while lysosomal components circulate on the autolysosomal surface through the autophagic lysosome reformation (ALR) process. Autolysosomes contain components from autophagosomes and lysosomes. However, whether there is a fusion between autolysosome and autophagosome or lysosome at the organelle level remains unknown. In this study, a pH and viscosity dual‐controlled mitochondria‐targeting fluorescent probe Mito‐Q was designed based on an asymmetric norcyanine to achieve the high‐contrast imaging of mitochondria‐containing autolysosomes. Mito‐Q not only effectively detected mitochondrial viscosity changes and mitophagy with high sensitivity, but more importantly, the fusion of mitochondria‐containing autolysosomes and autophagosomes (FMAA) was observed during autophagy by the real‐time confocal imaging of HeLa cells. [ABSTRACT FROM AUTHOR]

The N1,N2‐diphenyloxalohydrazide OX(HA)2 chemosensor was synthesized and used as a colorimetric and fluorescent receptor to detect Cu2+ and Fe3+ ions in the presence of other metal ions. A range of physicochemical approaches were utilized to characterize the symmetrical oxalohydrazide‐based receptor, including FT‐IR, 1H and 13C NMR, TGA, and mass spectrometry. According to single crystal X‐ray diffraction investigation, OX(HA)2 crystallizes in monoclinic with space group C2/c. UV‐Vis and fluorescence spectroscopy were used to thoroughly explore OX(HA)2's sensing capabilities towards diverse cations. Using measurements of fluorescence intensity, the binding constant for OX(HA)2 with Cu2+/Fe3+ ions was calculated to be 2.78×103 M−1 and 1.12×103 M−1 with the lower detection limit of 0.43 μM and 0.2 μM respectively. With a 1 : 1 binding mechanism validated by Job's plot, mass spectral analysis, FT‐IR spectra, and density functional theory, the dual‐sensing receptor exhibits remarkable selectivity and sensitivity towards Cu2+ and Fe3+ ions. The average fluorescence lifetimes of OX(HA)2, OX(HA)2+Cu2+, and OX(HA)2+Fe3+ were calculated to be 2.19 ns, 1.73 ns, and 1.26 ns, respectively. This fluorescence lifetime measurement results strongly support the complexation of Cu2+ and Fe3+. When Cu2+ and Fe3+ ions bind with OX(HA)2, they induce the 'Turn‐Off' signal. Then, fluorescence imaging of the OX(HA)2 receptor in MDA‐MB‐231 demonstrated that the receptor holds a lot of promise for usage in bioimaging and their IC50 value for cytotoxicity is 96.96 μg. Furthermore, fluorescence microscopy experiments demonstrate that OX(HA)2 can be utilized as a fluorescent probe for detecting Cu2+ and Fe3+ ions in living cells, making it potentially helpful as an anticancer medication. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) pathology is characterized by amyloid beta (Aβ) plaques and dysfunctional autophagy. Aβ is generated by sequential proteolytic cleavage of amyloid precursor protein (APP), and the site of intracellular APP processing is highly debated, which may include autophagosomes. Here, we investigated the involvement of autophagy, including the role of ATG9 in APP intracellular trafficking and processing by applying the RUSH system, which allows studying the transport of fluorescently labeled mCherry‐APP‐EGFP in a systematic way, starting from the endoplasmic reticulum. HeLa cells, expressing the RUSH mCherry‐APP‐EGFP system, were investigated by live cell imaging, immunofluorescence, and Western blot. We found that mCherry‐APP‐EGFP passed through the Golgi faster in ATG9 knockout cells. Furthermore, ATG9 deletion shifted mCherry‐APP‐EGFP from early endosomes and lysosomes toward the plasma membrane concomitant with reduced endocytosis. Importantly, this alteration in mCherry‐APP‐EGFP transport resulted in increased secreted mCherry‐soluble APP and C‐terminal fragment‐EGFP. These effects were also phenocopied by pharmacological inhibition of ULK1, indicating that autophagy is regulating the intracellular trafficking and processing of APP. These findings contribute to the understanding of the role of autophagy in APP metabolism and could potentially have implications for new therapeutic approaches for AD. [ABSTRACT FROM AUTHOR]

The Compact Morpho‐Molecular Microscopy (CM3) is proposed and demonstrated for multi‐functional imaging and characterization of living cells and material structures by simultaneously offering quantitative phase imaging (QPI), dispersion characterization, and fluorescence imaging. The compactness and stability of CM3 are realized by propagating lasers of different wavelengths in specially treated optical fibers and fiber‐based beam splitters and wavelength division multiplexers, as well as simplifying the detection scheme through Fourier‐space multiplexing and implementing a single camera for both QPI and fluorescence imaging. Quantitative phase maps of two wavelengths are retrieved from a multiplexed interferogram, and a synthesized wavelength phase map is derived to guide the height profiling of samples with extended depth. With the wavelength resolved phase maps, a physical model is derived to obtain sample dispersion parameters, which further enables us to quantify the hemoglobin concentration of red blood cells in real time. By inserting an appropriate emission color filter, fluorescence imaging is realized using the same camera, which significantly broadens the cell imaging applications of CM3. As a cost‐effective and multifaceted imaging method, CM3 may find many promising applications in live‐cell imaging and material characterization. [ABSTRACT FROM AUTHOR]

Standing wave (SW) microscopy is a method that uses an interference pattern to excite fluorescence from labelled cellular structures and produces high‐resolution images of three‐dimensional objects in a two‐dimensional dataset. SW microscopy is performed with high‐magnification, high‐numerical aperture objective lenses, and while this results in high‐resolution images, the field of view is very small. Here we report upscaling of this interference imaging method from the microscale to the mesoscale using the Mesolens, which has the unusual combination of a low‐magnification and high‐numerical aperture. With this method, we produce SW images within a field of view of 4.4 mm × 3.0 mm that can readily accommodate over 16,000 cells in a single dataset. We demonstrate the method using both single‐wavelength excitation and the multi‐wavelength SW method TartanSW. We show application of the method for imaging of fixed and living cells specimens, with the first application of SW imaging to study cells under flow conditions. LAY DESCRIPTION: With a standard microscope, it is possible to interfere two or more beams of light and produce a contour map of cell structures using a technique known as standing wave microscopy. This method is usually applied with high power objective lenses, and only a tiny area can be studied, usually showing structural detail from one or two cells at most. The Mesolens is a unique objective lens that has been designed and manufactured to image large populations of cells in a single image. Two‐dimensional images of cells can be obtained with the Mesolens using regular illumination methods, but the cell topography is lost. Here we have combined standing wave illumination with the Mesolens to perform topographical imaging of large numbers of cells in a single image. We first proved the method with a non‐biological specimen comprised of a glass lens, and then we applied the technique to imaging of fixed and living cells: in the case of red blood cells, we showed that we can study the topography of more than 16,000 cells in a single image. With the much larger area of study afforded by the Mesolens, we also used standing wave illumination for the first time monitor red blood cell topography when the cells are subject to flow environment. This new application of standing wave imaging at unusually large spatial scales may prove useful for studying behaviour in the circulatory system. [ABSTRACT FROM AUTHOR]

A series of functional glycopolymer nanoparticles with 1,8‐naphthalimide motif was designed, synthesized and applied for tumor cell imaging. With the pH‐sensitive and aggregation‐induced emission (AIE) effect of the 1,8‐naphthalimide fluorescent probe, the presence of glucose‐based glycopolymers enhanced its water‐solubility and biocompatibility. Owing to the dual tumor‐targeting effects of the dense glucose part and the boronic ester modification, the obtained glycopolymers showed high affinity to tumor cells, with a much faster staining rate than normal cells, indicating a great potential for diagnosis and treatments of cancers. [ABSTRACT FROM AUTHOR]

Pyrediyne, a recent addition to the 2D organic nanomaterials family, is known for its improved electrical conductivity, which can have potential applications in the performance of thin film transistors, field effect transistors, and charge storage devices. It has been shown that similar to carbon quantum dots, pyrediyne quantum dots (PDYQDs) can also be generated from 2D pyrediyne nanosheets and can be utilized for imaging cancer cells. In this context, it is highly desirable to enhance the photoluminescence properties of PDYQDs in order to improve the quality of quantum dots‐based cell imaging techniques. Herein, PDYQDs are effectively functionalized using aqueous functionalization agents such as NH3, PEG200, and PEG20000 via a simple and cost‐effective methodology, which resulted in a significant enhancement in the emission quantum yield (QY) (up to 30.2 %) through effectively reducing the non‐radiative recombination centers. After confirming their cytocompatibility using in vitro studies, the amine‐functionalized PDYQDs were utilized for imaging L929 mouse fibroblast cells. The findings in the present study suggest that it is worth exploring various surface functionalization techniques to enhance the applications of novel carbon‐based nano‐structures in various biological and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Summary: The nuclear TIR1/AFB‐Aux/IAA auxin pathway plays a crucial role in regulating plant growth and development. Specifically, the IAA17/AXR3 protein participates in Arabidopsis thaliana root development, response to auxin and gravitropism. However, the mechanism by which AXR3 regulates cell elongation is not fully understood.We combined genetical and cell biological tools with transcriptomics and determination of auxin levels and employed live cell imaging and image analysis to address how the auxin response pathways influence the dynamics of root growth.We revealed that manipulations of the TIR1/AFB‐Aux/IAA pathway rapidly modulate root cell elongation. While inducible overexpression of the AXR3‐1 transcriptional inhibitor accelerated growth, overexpression of the dominant activator form of ARF5/MONOPTEROS inhibited growth. In parallel, AXR3‐1 expression caused loss of auxin sensitivity, leading to transcriptional reprogramming, phytohormone signaling imbalance and increased levels of auxin. Furthermore, we demonstrated that AXR3‐1 specifically perturbs nuclear auxin signaling, while the rapid auxin response remains functional.Our results shed light on the interplay between the nuclear and cytoplasmic auxin pathways in roots, revealing their partial independence but also the dominant role of the nuclear auxin pathway during the gravitropic response of Arabidopsis thaliana roots. [ABSTRACT FROM AUTHOR]

This article examines the relationship between sunflower plants and the parasitic plant broomrape. The study reveals that broomrape infiltrates sunflower roots by entering the host cells, creating a new compartment. The researchers also observed cell divisions in the sunflower roots near the attachment sites, potentially leading to root enlargement. The study suggests that the parasitic plant damages the host cell walls with enzymes, but the host plants only exhibit minimal defense responses. These findings contribute to our understanding of parasitic plant interactions and may aid in the development of resistance strategies. [Extracted from the article]

A water‐soluble polymeric pyrene‐based polythioacetal (PTA‐Py) with thioacetal units in the main chain is simply synthesized by direct polycondensation of 3, 6‐dioxa‐1, 8‐octanedithiol, 1‐pyrene formaldehyde, and mPEG2k‐SH. The probe PTA‐Py shows a good fluorescence response to Hg2+ ions due to the Hg2+‐promoted deprotection reaction of thioacetal groups to regenerate the original 1‐pyrene formaldehyde compound. After adding Hg2+ to the PTA‐Py solution, the fluorescence intensity (FI) gradually increases with increasing concentrations of Hg2+. Compared with other metal ions, the probe exhibits high sensitivity, good selectivity, and rapid response to Hg2+. The low detection limits are 12.3 nm in ethanol‐PBS buffer and 13.3 nm in water, respectively. The results imply that the simply synthesized water‐soluble polymeric probe had potential applications in the rapid detection of Hg2+ ions in aqueous solutions. Moreover, the polymeric PTA‐Py shows high sensitivity for CH3Hg+ with detection limits of 26.5 nm in ethanol/PBS buffer. In addition, PTA‐Py can efficiently detect Hg2+ ions in HeLa cells. The results demonstrate that a valuable method is developed for biocompatible polymeric sensors for Hg2+ ions in biological and environmental samples. [ABSTRACT FROM AUTHOR]

Biologically‐active near‐ultraviolet emitting spirooxindole‐pyrrolidine/pyrrolothiazole‐β‐ketothiolester have been synthesised via Chemo‐/regio‐/stereoselective manner. Excited‐state intramolecular proton transfer (ESIPT) of β‐ketothiolester exhibits excitation‐dependent emission with intermolecular hydrogen bonding ability with solvents. The emission could be tunable between 330 nm to 460 nm. Selected fluorescent compounds 4{4,2,1}, 4{12,2,2}, 5{4,2,1} and 5{12,2,2} shows cytotoxicity effect on PC3 cells, where the highest IC50 value (6 μM) was found for the probe 5{12,2,2}. The fluorescent behavior of 5{4,2,1} and 5{12,2,2} acted as an imaging molecule against cancer cells. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) with tunable photoluminescence was successfully prepared via selective co‐doping of three elements, including nitrogen, phosphorus and sulfur element by green one‐step hydrothermal method. Nitrogen‐sulfur‐doped CDs (red NS‐CDs), which emitted red fluorescence under UV excitation, were used to detect iron ions in the linear range 1–50 μM, yielding detectable limits as low as 94 nM. The nitrogen‐phosphorus‐doped CDs (blue NP‐CDs) exhibited blue fluorescence with quantum yields up to 34.5 %. When the concentration is 800 μg/mL, it showed excellent anticancer effect in vitro. The nitrogen‐sulfur‐phosphorus‐doped CDs (green NPS‐CDs) emitting green fluorescence showed a low cytotoxicity at a high concentration of 800 μg/mL and were used for intracelluar imaging of NCl−H292 cells. This study demonstrated the photoluminescent characteristics of carbon dots (CDs) and highlighted the ability to modify their peak fluorescence emission wavelengths through the flexible combination of specific reagents under comparable hydrothermal conditions. Additionally, it provided valuable insights into the efficient methodologies for synthesizing CDs suitable for various application scenarios. [ABSTRACT FROM AUTHOR]

A promising new field of genetically encoded ultrasound contrast agents in the form of gas vesicles has recently emerged, which could extend the specificity of medical ultrasound imaging. However, given the delicate genetic nature of how these genes are integrated and expressed, current methods of producing gas vesicle-expressing mammalian cell lines requires significant cell processing time to establish a clonal/polyclonal line that robustly expresses the gas vesicles sufficiently enough for ultrasound contrast. Here, we describe an inducible and drug-selectable acoustic reporter gene system that can enable gas vesicle expression in mammalian cell lines, which we demonstrate using HEK293T cells. Our drug-selectable construct design increases the stability and proportion of cells that successfully integrate all plasmids into their genome, thus reducing the amount of cell processing time required. Additionally, we demonstrate that our drug-selectable strategy forgoes the need for single-cell cloning and fluorescence-activated cell sorting, and that a drug-selected mixed population is sufficient to generate robust ultrasound contrast. Successful gas vesicle expression was optically and ultrasonically verified, with cells expressing gas vesicles exhibiting an 80% greater signal-to-noise ratio compared to negative controls and a 500% greater signal-to-noise ratio compared to wild-type HEK293T cells. This technology presents a new reporter gene paradigm by which ultrasound can be harnessed to visualize specific cell types for applications including cellular reporting and cell therapies. [ABSTRACT FROM AUTHOR]

Developing a simple, selective, and rapid reliable method to monitor hypochlorous acid (HClO) in vivo is very meaningful due to its important physiological and pathological functions. In this research, a novel AIE based fluorescent probe for ratiometric detection of HClO was fabricated by a simple one‐step synthesis, in which the methyl sulfide group and salicylaldehyde azine serve as the recognition unit and fluorophore, respectively. This probe was visible‐light‐excitable, and showed a palpable aggregation‐induced emission into the red region with high stability to Cu2+ and pH. Oxidation of the methyl sulfide group can be achieved rapidly and specifically by HClO in physiological condition, which enables it to display a rapid, ratiometric fluorescent response to HClO with high selectivity over other biologically pertinent species. By exploiting the probe‐based tool, we successfully validated its practical utility in selectively recognizing HClO in living cells via ratiometric fluorescence signals, thereby providing a potential method for investigating the relevant functions of HClO in biosystems. [ABSTRACT FROM AUTHOR]

Langerhans cells (LCs) are mainly present in the epidermis and mucosa, and have important roles during skin infection. Migration of LCs to lymph nodes is essential for antigen presentation. However, due to the difficulties in isolating and culturing human LCs, it is not fully understood how LCs move and interact with the extracellular matrix (ECM) through their adhesion molecules such as integrin, during the immune responses. In this study, we aimed to investigate LC motility, cell shape and the role of integrin under inflammatory conditions using monocyte‐derived Langerhans cells (moLCs) as a model. As a result, lipopolysaccharide (LPS) stimulation increased adhesion on fibronectin coated substrate and integrin α5 expression in moLCs. Time‐lapse imaging of moLCs revealed that stimulation with LPS elongated cell shape, whilst decreasing their motility. Additionally, this decrease in motility was not observed when pre‐treated with a neutralising antibody targeting integrin α5. Together, our data suggested that activation of LCs decreases their motility by promoting integrin α5 expression to enhance their affinity to the fibronectin, which may contribute to their migration during inflammation. [ABSTRACT FROM AUTHOR]

Alzheimer's disease is associated with increased levels of amyloid beta (Aβ) generated by sequential intracellular cleavage of amyloid precursor protein (APP) by membrane‐bound secretases. However, the spatial and temporal APP cleavage events along the trafficking pathways are poorly defined. Here, we use the Retention Using Selective Hooks (RUSH) to compare in real time the anterograde trafficking and temporal cleavage events of wild‐type APP (APPwt) with the pathogenic Swedish APP (APPswe) and the disease‐protective Icelandic APP (APPice). The analyses revealed differences in the trafficking profiles and processing between APPwt and the APP familial mutations. While APPwt was predominantly processed by the β‐secretase, BACE1, following Golgi transport to the early endosomes, the transit of APPswe through the Golgi was prolonged and associated with enhanced amyloidogenic APP processing and Aβ secretion. A 20°C block in cargo exit from the Golgi confirmed β‐ and γ‐secretase processing of APPswe in the Golgi. Inhibition of the β‐secretase, BACE1, restored APPswe anterograde trafficking profile to that of APPwt. APPice was transported rapidly through the Golgi to the early endosomes with low levels of Aβ production. This study has revealed different intracellular locations for the preferential cleavage of APPwt and APPswe and Aβ production, and the Golgi as the major processing site for APPswe, findings relevant to understand the molecular basis of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Nucleic acids are considered as fundamental molecules of living systems, which serve as universal genetic information messengers and repositories. To uncover the multifaceted aspects of nucleic acid function and metabolism within cells, labeling has become indispensable. This labeling technique enables the visualization, isolation, characterization, and even quantification of specific nucleic acid species. This review delves into cellular metabolic approaches for nucleic acid labeling, wherein enzymatic steps are employed to introduce nucleic acid modifications before conjugation with a label for detection or isolation. The discussion begins with metabolic labeling for DNA, RNA with various reactive groups and post‐transcriptional RNA labeling for RNA methylation and acetylation sites, emphasizing recent advancements in the field and then, we spotlighted pertinent applications for cellular imaging and sequencing. of labeling. [ABSTRACT FROM AUTHOR]

Photoactivatable fluorophores are useful tools in live cell imaging due to precise spatial and temporal control. Herein, a tandem visible‐light photodecaging and tautomerization strategy is proposed as an activation mechanism for the construction of photoconvertible boron dipyrromethenes (BODIPY) dyes, from which nitro‐benzyloxy BODIPY derivatives are developed as a new class of visible light photoactivated fluorophores. Upon exposure to visible light, the nitro‐benzyloxy moiety is released and the BODIPY moiety is converted to the keto‐form BODIPY analog by tautomerization. The photoconversion process not only achieves over 50 nm blue shift of absorption/emission maxima but also provides bright fluorescence for both the pre‐ and post‐activation forms. Mechanism studies indicate that no indications of radical species and singlet oxygen are involved in this unique photoconversion and both UV and visible light irradiation can efficiently activate this photoinduced release of the nitrobenzyl alcohol through photoexciting of BODIPY core rather than classical nitro‐benzyloxy photocage. Cell and vesicle imaging is successfully performed using the new photoconversion dyes. The results show that these new photoconvertible dyes are highly efficient, universal, and non‐cytotoxic, which are valuable for the development of promising photoactivated molecules. [ABSTRACT FROM AUTHOR]

Understanding the factors that shape the circularly polarised luminescence (CPL) emission profiles of europium(III)‐based CPL emitters to have specific sign properties, e. g. monosignate individual CPL transitions, is key to design novel complexes for applications ranging from advanced security inks to bio‐probes for live cell imaging. In order to correlate structure and spectral characteristics, a photophysical and kinetic investigation has been conducted on a series of coordinatively saturated nine‐coordinate europium(III) systems based on 1,4,7‐triazacyclononane. We highlight that lanthanide emission is sensitive to changes in the ligand field by showing the linear dependence of total emission intensity ratios as a function of solvent polarity, for europium(III) complexes displaying an internal charge transfer (ICT) excited state. This sensitivity increases by a factor of 20 when studying changes in CPL spectra, rendering these complexes accurate probes of local polarity. Solvent polarity, solvent‐specific effects, and the nature of the chromophores' coordinating donor atoms strongly influence the kinetic stability of europium(III) complexes with respect to enantiomer interconversion. Notably, we show that the choice of donor groups to coordinating to europium(III) and the nature and polarity of the solvent affects the rate of racemisation, leading to systems with very long half‐lives at room temperature in non‐polar media. [ABSTRACT FROM AUTHOR]

Background: Line‐field confocal optical coherence tomography (LC‐OCT) is a new, valid means for a rapid and non‐invasive in vivo examination of the epidermis and upper dermis, allowing digital interpretation and measurement of high‐resolution images on a cellular level. Given these properties, it may represent a valid tool for monitoring psoriasis during treatment, allowing a new method to set a precise objective severity of the disease. Objectives: We aimed to investigate the potentialities of LC‐OCT in the non‐invasive monitoring of microscopical changes associated with moderate–severe plaque psoriasis (PP) during the treatment with the most common biological drugs. Materials and Methods: We performed LC‐OCT imaging of PP lesions from 17 patients before and after 8 weeks of treatment. The clinical severity of the single lesions was evaluated using a lesion score (LS), designed considering three parameters: erythema, desquamation and infiltration. LC‐OCT images were segmented by artificial intelligence and evaluated based on three microscopic criteria: the thickness of the stratum corneum, the thickness of the living epidermis and the undulation of the dermo‐epidermal junction. Results: Line‐field confocal optical coherence tomography digital analysis allowed recognition and quantification of the three microscopic criteria, showing a reduction of all these during the follow‐up. Furthermore, a high correlation between change in LS and the thickness of the stratum corneum and the thickness of the living epidermis was found. Conclusion: Line‐field confocal optical coherence tomography can non‐invasively monitor the response of PP to different treatments. Morphometric changes occurring in the psoriatic lesion during the 8‐week treatment period were identified by in vivo LC‐OCT and measured by using artificial intelligence. Although future studies are required, based on these preliminary results, LC‐OCT may represent a valid potential tool for precise monitoring of therapeutic response. [ABSTRACT FROM AUTHOR]

Graphene and graphene oxide (GO) have garnered significant attention due to their exceptional properties. GO, enriched with various functional groups such as epoxy, hydroxyl, and carboxylic groups, has exhibited remarkable potential in biomedical applications. The combination of GO with metals has proven to be a promising platform for cellular imaging, with this study focusing on the preparation of diverse hybrids of GO with metal oxides (GO/MO) and their potential as anticancer agents. In this research, GO is functionalized with MOs like TiO2, Fe3O4, and Cu2O using specific chemical methods and investigated for the anticancer activity for the application as cancer therapeutic agent. The resulting GO/MO hybrids exhibits favorable thermal and mechanical properties. Moreover, their cytotoxicity against human lung cancer cells is assessed in vitro, revealing the promising anticancer activity of GO/MO hybrids. Notably, the GO/Cu2O hybrid demonstrates particularly high cytotoxicity in human lung cancer cells. [ABSTRACT FROM AUTHOR]

Plant aquaporins (AQPs) facilitate the membrane diffusion of water and small solutes, including hydrogen peroxide (H2O2) and, possibly, cations, essential signalling molecules in many physiological processes. While the determination of the channel activity generally depends on heterologous expression of AQPs in Xenopus oocytes or yeast cells, we established a genetic tool to determine whether they facilitate the diffusion of H2O2 through the plasma membrane in living plant cells. We designed genetic constructs to co‐express the fluorescent H2O2 sensor HyPer and AQPs, with expression controlled by a heat shock‐inducible promoter in Nicotiana tabacum BY‐2 suspension cells. After induction of ZmPIP2;5 AQP expression, a HyPer signal was recorded when the cells were incubated with H2O2, suggesting that ZmPIP2;5 facilitates H2O2 transmembrane diffusion; in contrast, the ZmPIP2;5W85A mutated protein was inactive as a water or H2O2 channel. ZmPIP2;1, ZmPIP2;4 and AtPIP2;1 also facilitated H2O2 diffusion. Incubation with abscisic acid and the elicitor flg22 peptide induced the intracellular H2O2 accumulation in BY‐2 cells expressing ZmPIP2;5. We also monitored cation channel activity of ZmPIP2;5 using a novel fluorescent photo‐switchable Li+ sensor in BY‐2 cells. BY‐2 suspension cells engineered for inducible expression of AQPs as well as HyPer expression and the use of Li+ sensors constitute a powerful toolkit for evaluating the transport activity and the molecular determinants of PIPs in living plant cells. Summary statement: Nicotiana tabacum BY‐2 suspension cells engineered for HyPer expression as well as inducible expression of aquaporins and the use of a Li+ sensor constitute a powerful tool for evaluating hydrogen peroxide and cation transport activity in living plant cells. [ABSTRACT FROM AUTHOR]

Heavy metal contamination has become a global environmental problem and currently drawn much attention from researchers in worldwide. High exposure to heavy metals can lead to problems like kidney, liver and brain damage, skin and lung cancer, etc. Rapid and sensitive detection of heavy metals is of immense importance in environmental monitoring. Over the past few decades, enormous efforts have been made to design various sensors to identify and monitor these harmful metal ions. In Comparison with other methods, fluorescence‐based chemosensors have received extensive attention because of the advantages of high sensitivity, low cost, real‐time monitoring, simple operation, etc. The pyrene derivatives are significant polycyclic aromatic hydrocarbons (PAHs) with strong fluorescence. They are widely used as fluorescent probes in many applications due to their easy modification, high fluorescence quantum yield, and strong fluorescence emission in live cells, outstanding cell permeability, and very low cytotoxicity. The SDG 6: Clean water and sanitation alarm a strong strategy, and careful identification of the risk connected to environmental pollutants needs urgent attention in this situation. Therefore, we highlight different types of pyrene‐based fluorophores and the fluorescence mechanisms for the sensitive and selective detection methodology of Arsenic, Mercury, Cadmium, Lead, and Chromium heavy metals. [ABSTRACT FROM AUTHOR]

A macrocyclic confinement‐activated green phosphorescence and two‐photon near‐infrared (NIR) fluorescence supramolecular cascade assembly is constructed by multivalent interaction based on the alkyl‐bridged triphenylamine‐vinyl pyridine salts (BTPA), cucurbit[8]uril (CB[8]), β‐cyclodextrin‐grafted hyaluronic acid (HACD), and 4‐bromophenyl pyridine salt and CB[8] complex (PY/CB[8]). Taking advantage of CB[8]‐induced macrocyclic confinement and molecular folding, the fluorescence of BTPA is effectively redshifted by 30 nm from 720 to 750 nm. Subsequently, HACD, a cancer cell targeting agent, is co‐assembled with a BTPA/CB[8] supramolecular folder to form a nanoparticle, further enhancing NIR fluorescence from 750 nm up to 810 nm through cascade confinement. Upon introduction of the 2:1 complex PY/CB[8], multicomponent nanoparticles are fabricated, not only showing efficient NIR fluorescence with an increase in quantum yield from 7.21% to 22.92% but also endowing green phosphorescence emission, which is successfully applied for two‐photon cancer cell‐targeted imaging to shield background interference from fluorescent and phosphorescent resources. [ABSTRACT FROM AUTHOR]

A light controllable two‐photon near‐infrared (NIR) optical probe is conveniently constructed by multivalent supramolecular co‐assembly of amphiphilic sulfonatocalix[4]arene (SC4A), tricationic triphenylamine (TPA), and diarylethene derivative (DE). The obtained results indicate that the formed SC4A/TPA nanoparticle displays assemble‐confined behaviors and enhances the two‐photon excited NIR emission. Benefiting from the reversible ring‐opened and closed behaviors of the DE under 365 and > 600 nm light irradiation, the dicationic DE in the assembly could act as an energy acceptor after 365 nm light irradiation, then the co‐assembly of SC4A/TPA/DE could achieve a NIR fluorescence ON and OFF switch and is successfully applied in HeLa cell imaging, providing a convenient approach to supramolecular two‐photon switch for cell imaging. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions The role of Akt in nasal immunity is unstudied. Akt phosphorylates and activates endothelial nitric oxide synthase (eNOS) expressed in epithelial ciliated cells. Nitric oxide (NO) production by ciliated cells can have antibacterial and antiviral effects. Increasing nasal NO may be a useful antipathogen strategy in chronic rhinosinusitis (CRS). We previously showed that small‐molecule Akt activator SC79 induces nasal cell NO production and suppresses IL‐8 via the transcription factor Nrf‐2. We hypothesized that SC79 NO production may additionally have antibacterial effects.NO production was measured using fluorescent dye DAF‐FM. We tested effects of SC79 during co‐culture of Pseudomonas aeruginosa with primary nasal epithelial cells, using CFU counting and live–dead staining to quantify bacterial killing. Pharmacology determined the mechanism of SC79‐induced NO production and tested dependence on Akt.SC79 induced dose‐dependent, Akt‐dependent NO production in nasal epithelial cells. The NO production required eNOS and Akt. The NO released into the airway surface liquid killed P. aeruginosa. No toxicity (LDH release) or inflammatory effects (IL8 transcription) were observed over 24 h.Together, these data suggest multiple immune pathways are stimulated by SC79, with antipathogen effects. This in vitro pilot study suggests that a small‐molecule Akt activator may have clinical utility in CRS or respiratory other infection settings, warranting future in vivo studies. [ABSTRACT FROM AUTHOR]

Detection of correct oxidation state of a metal ion is important to understand its speciation and redox properties. Some of rhodamine derivatives can identify Al3+, Cr3+ and Fe3+ as the trivalent cations. We have synthesized a rhodamine derivative, HL‐qui, from the reaction of N‐(rhodamine‐6G)lactam‐ethylenediamine with quinoline‐2‐carboxaldehyde for the colorimetric as well as fluorogenic detection of all of metal ions with +3 oxidation state such as Al3+, Cr3+, Fe3+, Ga3+, In3+, Tl3+ and Gd3+. In the presence of these trivalent cations, colorless and nonfluorescent HL‐qui turns pink and strongly fluorescent in HEPES buffer (10 mM) in H2O/ethanol=1/9 (v/v) (pH 7.4) as its spirolactam ring gets open to show the changes in color and fluorescence properties. High sensitivity of the probe towards the cations is reflected from the limit of detection values that are in nM range. To the best of our knowledge, there is no such report where fluorescence sensing has been utilized to determine oxidation state. This multi‐ion sensing feature has been used for fabrication of multi input‐output based logic circuit using Boolean algebraic method. It has been used in imaging of metal ions in living cell (L6 cells). [ABSTRACT FROM AUTHOR]

Fluorescent probes are valuable tools to visualize non‐catalytic proteins in live cells. Currently, the majority of imaging reagents for non‐catalytic proteins are based on "always‐on" fluorophores and the use of these reagents usually necessitate a wash step to remove unbounded fluorophores before microscope imaging. Herein, we report the use of arylamino‐substituted rhodamine as an activatable fluorophore for the imaging of non‐catalytic protein in live cells. We have shown the induction of an arylamino to structurally rigid rhodamine could significantly reduce the fluorescent emission in aqueous medium but the ligand‐directed binding of this molecule to protein receptor could effective restrict its intramolecular motion and thus lead to enhancement in fluorescence intensity at 590 nm over 30‐fold. With fluorescent probes based on this fluorophore, we could visualize integrin αvβ3 and azido‐functionalized glycans in living cells with high contrast in a wash‐free manner. [ABSTRACT FROM AUTHOR]

Most mammalian cells have a single primary cilium that acts as a signalling hub in mediating cellular functions. However, little is known about the mechanisms that result in aberrant supernumerary primary cilia per cell. In this study, we re‐analysed a previously published whole‐genome siRNA‐based reverse genetic screen for genes mediating ciliogenesis to identify knockdowns that permit multi‐ciliation. We identified siRNA knockdowns that caused significant formation of supernumerary cilia, validated candidate hits in different cell‐lines and confirmed that RACGAP1, a component of the centralspindlin complex, was the strongest candidate hit at the whole‐genome level. Following loss of RACGAP1, mother centrioles were specified correctly prior to ciliogenesis and the cilia appeared normal. Live cell imaging revealed that increased cilia incidence was caused by cytokinesis failure which led to the formation of multinucleate cells with supernumerary cilia. This suggests that the signalling mechanisms for ciliogenesis are unable to identify supernumerary centrosomes and therefore allow ciliation of duplicated centrosomes as if they were in a new diploid daughter cell. These results, demonstrating that aberrant ciliogenesis is de‐coupled from cell cycle regulation, have functional implications in diseases marked by centrosomal amplification. [ABSTRACT FROM AUTHOR]

By synergistically employing four key strategies: (I) introducing tetraphenylethylene groups as the central core unit with aggregation‐induced emission (AIE) properties, (II) optimizing the π‐conjugated length by extending the building block branches, (III) incorporating flexible groups containing ethylenic bonds, and (IV) applying crystal engineering to attain dense stacking mode and highly twisty conformation, we successfully synthesized a series of hydrogen‐bonded organic frameworks (HOFs) exhibiting exceptional one/two‐photon excited fluorescence. Notably, when utilizing the fluorescently superior building block L2, HOF‐LIFM‐7 and HOF‐LIFM‐8 exhibiting high quantum yields (QY) of 82.1 % and 77.1 %, and ultrahigh two‐photon absorption (TPA) cross‐sections of 148959.5 GM and 123901.1 GM were achieved. These materials were successfully employed in one and two‐photon excited lysosome‐targeting cellular imaging. It is believed that this strategy, combining building block optimization and crystal engineering, holds significant potential for guiding the development of outstanding fluorescent HOF materials. [ABSTRACT FROM AUTHOR]

Various fluorogenic probes utilizing tetrazine (Tz) as a fluorescence quencher and bioorthogonal reaction partner have been extensively studied over the past few decades. Herein, we synthesized a series of boron‐dipyrromethene (BODIPY)‐Tz probes using monochromophoric design strategy for bioorthogonal cellular imaging. The BODIPY‐Tz probes exhibited excellent bicyclo[6.1.0]nonyne (BCN)‐selective fluorogenicity with three‐ to four‐digit‐fold enhancements in fluorescence over a wide range of emission wavelengths, including the far‐red region. Furthermore, we demonstrated the applicability of BODIPY‐Tz probes in bioorthogonal fluorescence imaging of cellular organelles without washing steps. We also elucidated the aromatized pyridazine moiety as the origin of BCN‐selective fluorogenic behavior. Additionally, we discovered that the fluorescence of the trans‐cyclooctene (TCO) adducts was quenched in aqueous media via photoinduced electron transfer (PeT) process. Interestingly, we observed a distinctive recovery of the initially quenched fluorescence of BODIPY‐Tz‐TCO upon exposure to hydrophobic media, accompanied by a significant bathochromic shift of its emission wavelength relative to that exhibited by the corresponding BODIPY‐Tz‐BCN. Leveraging this finding, for the first time, we achieved dual‐color bioorthogonal cellular imaging with a single BODIPY‐Tz probe. [ABSTRACT FROM AUTHOR]