Advances In Fluorescent Probes Research Articles

Recent Advances in Fluorescent Probes for Cancer Biomarker Detection.

Many important biological species have been identified as cancer biomarkers and are gradually becoming reliable targets for early diagnosis and late therapeutic evaluation of cancer. However, accurate quantitative detection of cancer biomarkers remains challenging due to the complexity of biological systems and the diversity of cancer development. Fluorescent probes have been extensively utilized for identifying biological substances due to their notable benefits of being non-invasive, quickly responsive, highly sensitive and selective, allowing real-time visualization, and easily modifiable. This review critiques fluorescent probes used for detecting and imaging cancer biomarkers over the last five years. Focuses are made on the design strategies of small-molecule and nano-sized fluorescent probes, the construction methods of fluorescence sensing and imaging platforms, and their further applications in detection of multiple biomarkers, including enzymes, reactive oxygen species, reactive sulfur species, and microenvironments. This review aims to guide the design and development of excellent cancer diagnostic fluorescent probes, and promote the broad application of fluorescence analysis in early cancer diagnosis.

Recent advances in fluorescent probes of peroxynitrite: Structural, strategies and biological applications

Peroxynitrite (ONOO-), owing to its high oxidative and nitrating stress, is associated with several physiological processes in addition to various pathological processes, including those related to neurodegenerative diseases and cancer. Detection of ONOO- at the cellular level is of great significance to understand its pathogenesis. To this end, a variety of fluorescent probes based on small molecules and nanoparticles (NPs) have been engineered and applied as excellent tools for imaging of ONOO- in cells as well as in their diverse biological applications. In this review, we highlight representative cases of fluorescent probes based on recognition mechanism and emphasize their response type (ratiometric, two-photon, long-wavelength/near-infrared, and targeting) in ONOO- detection in the last five years. We further discuss their design strategy, sensing mechanism, and application in bio-imaging and describe NP-based probes according to diverse nanoplatforms.

Recent Advances in Molecular Fluorescent Probes for CYP450 Sensing and Imaging

Cytochrome P450 (CYP450) is a major drug-metabolizing enzyme system mainly distributed in liver microsomes and involved in the metabolism of many endogenous substances (such as fatty acids and arachidonic acids), and exogenous compounds (such as drugs, toxicants, carcinogens, and procarcinogens). Due to the similarity in structures and catalytic functions between CYP450 isoforms, the lack of effective selective detection tools greatly limits the understanding and the research of their respective physiological roles in living organisms. Until now, several small-molecular fluorescent probes have been employed for selective detection and monitoring of CYP450s (Cytochrome P450 enzymes) in vitro or in vivo owing to the tailored properties, biodegradability, and high temporal and spatial resolution imaging in situ. In this review, we summarize the recent advances in fluorescent probes for CYP450s (including CYP1, CYP2, and CYP3 families), and we discuss and focus on their identification mechanisms, general probe design strategies, and bioimaging applications. We also highlight the potential challenges and prospects of designing new generations of fluorescent probes in CYP450 studies, which will further enhance the diversity, practicality, and clinical feasibility of research into CYP450.

Recent advances in fluorescent probes for lipid droplets.

Lipid droplets (LDs) have been known as a non-negligible cellular organelle for lipid storage and metabolism. Fluorescent probes for imaging LDs would be paramount for depicting their functions in cells. Although commercially available Nile Red and BODIPYtm 493/503 have been widely used for labelling LDs, they exhibit unsatisfactory specificity and spectroscopic properties. This feature article reviews the recent advances in organic fluorescent probes for imaging LDs. We first introduce the key points for probe design, including regulating hydrophobicity and enhancing fluorescence quantum yield in LDs. Then, we summarize the structural features and biological applications of some representative LD probes classified by their frameworks. In addition, the current challenges and future research trends for the fluorescent probes of LDs are discussed as well.

Advances in fluorescent probes for detection and imaging of amyloid-β peptides in Alzheimer's disease.

Amyloid plaques generated from the accumulation of amyloid-β peptides (Aβ) fibrils in the brain is one of the main hallmarks of Alzheimer's disease (AD), a most common neurodegenerative disorder. Aβ aggregation can produce neurotoxic oligomers and fibrils, which has been widely accepted as the causative factor in AD pathogenesis. Accordingly, both soluble oligomers and insoluble fibrils have been considered as diagnostic biomarkers for AD. Among the existing analytical methods, fluorometry using fluorescent probes has exhibited promising potential in quantitative detection and imaging of both soluble and insoluble Aβ species, providing a valuable approach for the diagnosis and drug development of AD. In this review, the most recent advances in the fluorescent probes for soluble or insoluble Aβ aggregates are discussed in terms of design strategy, probing mechanism, and potential applications. In the end, future research directions of fluorescent probes for Aβ species are also proposed.

Recent Advances in Fluorescent Probes for Biothiols

Recent Advances in Fluorescent Probes for Biothiols

Exploiting molecular probes to perform near‐infrared fluorescence‐guided surgery

AbstractNear‐infrared (NIR) fluorescence imaging can provide real‐time navigation for surgeons to discriminate boundaries between lesions and healthy tissue, which serves as a promising tool to enhance precise diagnosis and accurate excision during surgery. Molecular probes with NIR fluorescence can visualize diseased tissue in deep penetration with improved signal‐to‐noise ratio, which considerably encourages the active participation of NIR fluorescence‐guided surgery in the operating room. Although a great quantity of fluorescent probes has been employed in clinical trials, the U.S. Food and Drug Administration only approves an extremely narrow number of contrast agents for clinical use so far. Currently, there remain two significant problems to be addressed in surgical resection: accurate identification of diseased tissue and the preservation of adjacent vital structures. Here, molecular probes with NIR fluorescence are systematically reviewed to offer possible solutions to these two problems. Targeting strategies of fluorescent probes are introduced, where the strengths and weaknesses of each strategy are presented. Advances in fluorescent probes for the imaging of vital structures, such as nerve and ureter, are also summarized in this review. It is convinced that NIR fluorescence‐guided surgery has the potential to improve current surgical resection and ameliorate the postoperative outcomes of diverse diseases.

Fluorescent Bioconjugates for Super-Resolution Optical Nanoscopy.

Fluorescent microscopy techniques are widely used in biological studies. However, the spatial resolution of fluorescent microscopy is restricted by the optical diffraction limit. In the past two decades, super-resolution imaging techniques with different principles have been invented to visualize biomolecules at nanometer scales. The development of nearly all these techniques is closely related to the advances in fluorescent probes. In particular, the intrinsic properties of fluorescent probes constrain the optimal imaging performance of super-resolution nanoscopy techniques. In this review, we summarized the recent progress in fluorescent probe bioconjugates for super-resolution imaging techniques. Examples of these bioconjugates include the widely used fluorescent proteins (FPs), organic dyes, quantum dots (Qdots), carbon dots (Cdots), upconversion nanoparticles (UCNPs), aggregation induced emission (AIE) nanoparticles, and polymer dots (Pdots). Based on the characteristics of the existing probes and their adaptability in current imaging methods, we provide a perspective for further development of fluorescent probes for super-resolution imaging.

Recent advances in fluorescent probes for G-quadruplex nucleic acids

G-quadruplexes are non-canonical nucleic acid structures formed by guanine-rich DNA or RNA sequences. In recent decades, an increasing number of evidences have suggested that G-quadruplexes are associated with a wide range of biological events. Therefore, to further study the function and distribution of G-quadruplexes, developing new probes is an essential part of G-quadruplexes research. In the review, several examples of chemical fluorescent probes for G-quadruplexes developed in recent years are highlighted. These probes are promising tools for future G-quadruplex studies, which display outstanding selectivity and capability of cell imaging.

Recent Advances in Fluorescent Probes for Detection of HOCl and HNO.

It is known that reactive oxygen (ROS) and nitrogen (RNS) species play a diverse role in various biological processes, such as inflammation, signal transduction, and neurodegenerative injury, apart from causing various diseases caused by oxidative and nitrosative stresses, respectively, by ROS and RNS. Thus, it is very important to quantify the concentration level of ROS and RNS in live cells, tissues, and organisms. Various small-molecule-based fluorescent/chemodosimetric probes are reported to quantify and map the effective distribution of ROS/RNS under in vitro/in vivo conditions with a great spatial and temporal resolution. Such reagents are now appreciated as an excellent tool for aiding breakthroughs in modern redox biology. This mini-review is a brief, but all-inclusive, account of such molecular probes that have been developed recently.

Recent advances in molecular fluorescent probes for organic phosphate biomolecules recognition

Organic phosphate biomolecules (OPBs) are indispensable components of eukaryotes and prokaryotes, such as acting as the fundamental components of cell membranes and important substrates for nucleic acids. They play pivotal roles in various biological processes, such as energy conservation, metabolism, and signal modulation. Due to the difficulty of detection caused by variety OPBs, investigation of their respective physiological effects in organisms has been restrained by the lack of efficient tools. Many small fluorescent probes have been employed for selective detection and monitoring of OPBs in vitro or in vivo due to the advantages of tailored properties, biodegradability and in situ high temporal and spatial resolution imaging. In this review, we summarize the recent advances in fluorescent probes for OPBs, such as nucleotides, NAD(P)H, FAD/FMN and PS. Importantly, we describe their identification mechanisms in detail and discuss the general strategies for these OPBs probe designs, which provide new insights and ideas for the future probe designs.

Recent advances in fluorescent probes for peroxynitrite detection

Peroxynitrite (ONOO−), known as a kind of reactive nitrogen species, is a significant factor involved in a broad spectrum of physiological and pathological processes. However, their biological functions remain to be controversial or poorly characterized yet, mainly because of the lack of reliable methods for sensitive and specific detection of ONOO− in vitro and in vivo. Thus, approaches that enable noninvasive visualized imaging of ONOO− will be of enormous benefit in understanding the processes of related diseases and developing novel drugs. During the last decades, fluorescent probes, with high sensitivity and real-time spatial imaging capacity, receive more and more attention. Herein, we strive to summarize the current fluorescent probes for ONOO−, including small-molecular fluorescent probes, nanoparticles-based fluorescent probes, and genetically encoded fluorescent probes. Furthermore, the challenges and attempt to give an outlook on the possible further developments are discussed.

Recent Advances in Fluorescent Probes for Lipid Droplets.

Lipid droplets (LDs) are organelles that serve as the storage of intracellular neutral lipids. LDs regulate many physiological processes. They recently attracted attention after extensive studies showed their involvement in metabolic disorders and diseases such as obesity, diabetes, and cancer. Therefore, it is of the highest importance to have reliable imaging tools. In this review, we focus on recent advances in the development of selective fluorescent probes for LDs. Their photophysical properties are described, and their advantages and drawbacks in fluorescence imaging are discussed. At last, we review the reported applications using these probes including two-photon excitation, in vivo and tissue imaging, as well as LDs tracking.

Functional insights into pathogen biology from 3D electron microscopy.

In recent years, novel imaging approaches revolutionised our understanding of the cellular and molecular biology of microorganisms. These include advances in fluorescent probes, dynamic live cell imaging, superresolution light and electron microscopy. Currently, a major transition in the experimental approach shifts electron microscopy studies from a complementary technique to a method of choice for structural and functional analysis. Here we review functional insights into the molecular architecture of viruses, bacteria and parasites as well as interactions with their respective host cells gained from studies using cryogenic electron tomography and related methodologies.

Recent progress in fluorescent probes for cholinesterase

Cholinesterases, a series of glycoprotein hydrolases, mainly consist of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) and they are isoenzymes. They mainly exist in brain, blood and many other tissues of human body, and they widely involve into many physiological metabolic processes like the metabolism, the nutritional synthesis and the energy transfer. Thus, cholinesterases play significant roles in multiple research areas, such as neurobiology, toxicology, clinical medicine and pharmacol. Therefore, the assay and analysis of cholinesterases activity is very important for the drug discovery and the clinical diagnosis of cholinesterases related diseases. In this review, we mainly focus on the recent advances in fluorescent probes and the development of the fluorometric methods for the biological analysis of cholinesterase, the inhibitor based probe, the substrate based probe, as well as the nanomaterial based fluorometric assays.

Advances in fluorescence labeling strategies for dynamic cellular imaging.

Synergistic advances in optical physics, probe design, molecular biology, labeling techniques and computational analysis have propelled fluorescence imaging into new realms of spatiotemporal resolution and sensitivity. This review aims to discuss advances in fluorescent probes and live-cell labeling strategies, two areas that remain pivotal for future advances in imaging technology. Fluorescent protein- and bio-orthogonal-based methods for protein and RNA imaging are discussed as well as emerging bioengineering techniques that enable their expression at specific genomic loci (for example, CRISPR and TALENs). Important attributes that contribute to the success of each technique are emphasized, providing a guideline for future advances in dynamic live-cell imaging.

Recent Advances in Fluorescent Probes for Monitoring of Hydrogen Sulfide

Hydrogen sulfide (H₂S), known for its unpleasant rotten egg smell and its high toxicity, has recently emerged as an important mediator of human physiological and pathological processes, such as the regulation of cell growth, cardiovascular protection, the stimulation of angiogenesis, gastric mucosal injury and Alzheimer's disease. Due to its significant actions in the physiology, H₂S has attracted the abundant concern of numerous researchers in the cutting edge of chemistry, biology and medicine. Recently, several fluorescent probes have been developed for detecting and elucidating the role played by H₂S in biological systems. This review highlights recent advances that have been made on the mechanism and applications of fluorescent probes for the detection of H₂S, demonstrating a new field in which remarkable improvements have been accomplished over the last two years.

Recent Advances in Fluorescent Probes for the Detection of Hydrogen Sulfide

Hydrogen sulfide (H2S) has been recognized as one of the three important gasotransmitters along with nitric oxide (NO) and carbon monoxide (CO). H2S plays regulatory roles in the cardiovascular system (CV), central nervous system (CNS), respiratory system, gastrointestinal system, and endocrine system. The study to understand its molecular mechanism is still ongoing. Current methods for the detection of H2S include chromatographic methods, electrochemical methods, and colorimetric/fluorometric methods. Fluorescent sensors and probes are especially important in modern analysis due to their high sensitivity, which can provide nanomolar detection; their compatibility with high-throughput screening (HTS), which allows for rapid assessment; and their applicability in live cell bioimaging, which allows real-time detection/observation. This review focuses on strategies used in designing fluorescent sensors and probes for H2S and their applications.

Advances in Fluorescent Probes Based on the Small Molecules for Zn2+

Advances in Fluorescent Probes Based on the Small Molecules for Zn²⁺

High-Content Analysis in Preclinical Drug Discovery

High-Content Analysis (HCA) has developed into an established tool and is used in a wide range of academic laboratories and pharmaceutical research groups. HCA is now routinely proving to be effective in providing functionally relevant results. It is essential to select the appropriate HCA application with regard to the targeted compound's cellular function. The cellular impact and compound specificity as revealed by HCA analysis facilitates reaching definitive conclusions at an early stage in the drug discovery process. This technology therefore has the potential to substantially improve the efficiency of pharmaceutical research. Recent advances in fluorescent probes have significantly boosted the success of HCA. Auto-fluorescent proteins which minimally hinder the functioning of the living cell have been playing a decisive role in cell biology research. For companies the severely restricted license conditions regarding auto-fluorescent proteins hamper their general use in pharmaceutical research. This has opened the field for other solutions such as self-labeling protein technology, which could potentially replace the well established methods that utilize auto-fluorescent proteins. In addition, direct labeling techniques have improved considerably and may supersede many of the approaches based on fusion proteins. Following sample preparation, treated cells are imaged and the resulting multiple fluorescent signals are subjected to contextual and statistical analysis. The extraordinary advantage of HCA is that it enables the large-scale and simultaneous quantification and correlation of multiple phenotypic responses and physiological reactions using sophisticated software solutions that permit assay-specific image analysis. Hence, HCA once more has demonstrated its outstanding potential to significantly support establishing effective pharmaceutical research processes in order to both advance research projects and cut costs.