An antagonist-based two-photon fluorogenic probe for imaging metabotropic glutamate receptor 5 in neuronal cells.

The expression of metabotropic glutamate receptor 5 (mGluR5) is subject to developmental regulation and undergoes significant changes in neuropsychiatric disorders and diseases. Visualizing mGluR5 by fluorescence imaging is a highly desired innovative technology for biomedical applications. Nevertheless, there are substantial problems with the chemical probes that are presently accessible. In this study, we have successfully developed a two-photon fluorogenic probe, mGlu-5-TP, based on the structure of mGluR5 antagonist 6-methyl-2-(phenylethynyl)pyridine (MPEP). Due to this antagonist-based probe selectively recognizes mGluR5, high expression of mGluR5 on living SH-SY5Y human neuroblastoma cells has been detected during intracellular inflammation triggered by lipopolysaccharides (LPS). Of particular significance, the probe can be employed along with two-photon fluorescence microscopy to enable real-time visualization of the mGluR5 in Aß fiber-treated neuronal cells, thereby establishing a connection to the progression of Alzheimer's disease (AD). These results revealed that the probe can be a valuable imaging tool for studying mGluR5-related diseases in the nervous system.

Real-time monitoring of abnormal mitochondrial viscosity in glioblastoma with a novel mitochondria-targeting fluorescent probe.

Glioblastoma is the most fatal and insidious malignancy, due to the existence of the blood-brain barrier (BBB) and the high invasiveness of tumor cells. Abnormal mitochondrial viscosity has been identified as a key feature of malignancies. Therefore, this study reports on a novel fluorescent probe for mitochondrial viscosity, called ZVGQ, which is based on the twisted intramolecular charge transfer (TICT) effect. The probe uses 3-dicyanomethyl-1,5,5-trimethylcyclohexene as an electron donor moiety and molecular rotor, and triphenylphosphine (TPP) cation as an electron acceptor and mitochondrial targeting group. ZVGQ is highly selective, pH and time stable, and exhibits rapid viscosity responsiveness. In vitro experiments showed that ZVGQ could rapidly recognize to detect the changes in mitochondrial viscosity induced by nystatin and rotenone in U87MG cells and enable long-term imaging for up to 12 h in live U87MG cells. Additionally, in vitro 3D tumor spheres and in vivo orthotopic tumor-bearing models demonstrated that the probe ZVGQ exhibited exceptional tissue penetration depth and the ability to penetrate the BBB. The probe ZVGQ not only successfully visualizes abnormal mitochondrial viscosity changes, but also provides a practical and feasible tool for real-time imaging and clinical diagnosis of glioblastoma.

Cascading Detection of Hydrogen Sulfide and N-Acetyltransferase 2 in Hepatocellular Carcinoma Cells Using a Two-Photon Fluorescent Probe.

Hydrogen sulfide (H2S), a critical gas signaling molecule, and N-acetyltransferase 2 (NAT2), a key enzyme in drug metabolism, are both known active biomarkers for liver function. However, the interactions and effects of H2S and NAT2 in living cells or lesion sites remain unknown due to the lack of imaging tools to achieve simultaneous detection of these two substances, making it challenging to implement real-time imaging and precise tracking. Herein, we report an activity-based two-photon fluorescent probe, TPSP-1, for the cascade detection of H2S and NAT2 in living liver cells. Continuous conversion from TPSP-1 to TPSP-3 was achieved in liver cells and tissues. Significantly, leveraging the outstanding optical properties of this two-photon fluorescent probe, TPSP-1, has been effectively used to identify pathological tissue samples directly from clinical liver cancer patients. This work provides us with this novel sensing and two-photon imaging probe, which can be used as a powerful tool to study the physiological functions of H2S and NAT2 and will help facilitate rapid and accurate diagnosis and therapeutic evaluation of hepatocellular carcinoma.

A novel near-infrared fluorescent probe for real-time monitoring of leucine aminopeptidase activity and metastatic tumor progression.

This article discusses the importance of early tumor detection, particularly in liver cancer, and the role of leucine aminopeptidase (LAP) as a potential marker for liver cancer diagnosis and prognosis assessment. The article highlights the limitations of current tumor markers and the need for new markers and multi-marker approaches to improve accuracy. The authors introduce a novel near-infrared fluorescent probe, NTAP, designed for LAP detection. They describe the synthesis of the probe and evaluate its spectral properties, including the LOD was 0.0038 U/mL, and QY was 0.32 %. The kinetic properties of NTAP, such as the relationship between LAP concentration (0-0.08 U/mL), reaction time (3 min), and fluorescence excitation spectra (475 nm) and emission spectra (715 nm) are investigated. The article also discusses the stability and selectivity of the probe and its ability to detect LAP in complex samples. Cellular imaging experiments demonstrate the NATP specificity and selectivity in detecting LAP activity and its inhibition. Animal models of liver and lung metastasis are used to evaluate the probe's imaging capabilities, showing its ability to accurately locate and detect metastatic lesions. The article concludes by emphasizing the potential applications of the NTAP probe in early tumor diagnosis, treatment monitoring, and the study of tumor metastasis mechanisms.

Development of a hypoxia-activated red-emission fluorescent probe for in vivo tumor microenvironment imaging and anti-tumor therapy.

Hypoxia, a significant feature of the tumor microenvironment, is closely associated with tumor growth, metastasis, and drug resistance. In the field of tumor microenvironment analysis, accurately imaging and quantifying hypoxia - a critical factor associated with tumor progression, metastasis, and resistance to therapy - remains a significant challenge. Herein, a hypoxia-activated red-emission fluorescent probe, ODP, for in vivo imaging of hypoxia in the tumor microenvironment is presented. Among various imaging methods, optical imaging is particularly convenient due to its rapid response and high sensitivity. The ODP probe specifically targets nitroreductase (AzoR), an enzyme highly expressed in hypoxic cells, playing a vital role by catalyzing the cleavage of azo bonds. The optical properties of ODP exhibited excellent performance in terms of fluorescence enhancement, fluorescence lifetime (0.81 ns), and detection limit (0.86 µM) in response to SDT. Cell imaging experiments showed that ODP could effectively detect and image intracellular hypoxia and the imaging capability of ODP was studied under various conditions including cell migration, antioxidant treatment, and different incubation times. Through comprehensive in vitro and in vivo experiments, including cellular imaging and mouse tumor models, this work demonstrates the efficacy of ODP in accurately detecting and imaging hypoxia. Moreover, ODP's potential in inducing apoptosis in cancer cells offers a promising avenue for integrating diagnostic and therapeutic strategies in cancer treatment. This innovative approach not only contributes to the understanding and assessment of tumor hypoxia but also opens new possibilities for targeted cancer therapy.

Synthesis and biological evaluation of triazolones/oxadiazolones as novel urease inhibitors.

Urease is the main virulence factor of infectious gastritis and gastric ulcers. Urease inhibitors are regarded as the first choice for the treatment of such diseases. Based on the triazolone/oxadiazolone skeleton, a urea-like fragment being able to specifically bind the urease activity pocket and prevent urea from hydrolysis, we designed and synthesized 45 triazolones/oxadiazolones as urease inhibitors. Eight compounds were proved to show excellent inhibitory activity against Helicobacter pylori urease, being more potency than the clinically used urease inhibitor acetohydroxamic acid. The most active inhibitor with IC50 value of 1.2 µM was over 20-fold higher potent than the positive control. Enzymatic kinetic assays showed that these novel inhibitors reversibly inhibited urease with a mixed competitive mechanism. Molecular dockings provided evidence for the observations in enzyme assays. Furthermore, these novel inhibitors were proved as drug-like compounds with very low cytotoxicity to mammalian cells and favorable water solubility. These results suggested that triazolone and oxadiazolone were promising scaffolds for the design and discovery of novel urease inhibitors, and were expected as good candidates for further drug development.

Rational design of mitochondria-targeted fluorescent biosensors for in vivo elucidation of the interaction between breast cancer metastasis and mitochondrial autophagy.

Breast cancer lung metastases (BCLM) are a major cause of high mortality in patients. The shortage of therapeutic targets and rapid drug screening tools for BCLM is a major challenge at present. Mitochondrial autophagy, which involves the degradation of proteins associated with cancer cell aggressiveness, represents a possible therapeutic approach for the treatment of BCLM. Herein, four fluorescent biosensors with different alkyl chains were designed and synthesized to monitor mitochondrial autophagy. Among them, PMV-12 demonstrated the highest sensitivity to viscosity variance, the least impact on polarity, and the longest imaging time. The introduction of the C12-chain made PMV-12 anchored in the mitochondrial membrane without being disturbed by changes of the mitochondrial membrane potential (MMP), thereby achieving the long-term monitor in situ for mitochondrial autophagy. Mitochondria stained with PMV-12 induced swelling and viscosity increase after treating with apigenin, which indicated that apigenin is a potential mitochondrial autophagy inducer. Apigenin was subsequently verified to inhibit cancer cell invasion by 92%. Furthermore, PMV-12 could monitor the process of BCLM in vivo and evaluate the therapeutic effects of apigenin. This work provides a fluorescent tool for elucidating the role of mitochondrial autophagy in the BCLM process and for anti-metastatic drug development.

Grid composite meta-surface absorber with thermal isolation structure for terahertz detection.

This paper specifically focuses on the absorber, the critical component responsible for the detector's response performance. The meta-surface absorber combines two resonant structures and achieves over 80% absorptance around 210 GHz, resulting in a broad operating frequency range. FR-4 is selected as the dielectric layer to be compatible with standard printed circuit board (PCB) technology, which reduces the overall fabrication time and cost. The absorbing unit and array layout are symmetrically designed, providing stable absorptance performance even under incident waves of different polarization angles. The polarization-insensitive absorptance characteristic further enhances the compatibility between the absorber and the detector in the application scenario. Furthermore, the thermal insulation performance of the absorber is ensured by introducing thermal insulation gaps. After completing fabrication through PCB technology, testing revealed that the absorber maintained excellent absorptance performance within its primary operating frequency range. This performance consistency closely matched the simulation results.

Promoting In Vivo NIR-II Fluorescent Imaging for Lipid in Lipid Metabolism Diseases Diagnosis.

Lipid metabolism diseases have become a tremendous risk worldwide, along with the development of productivity and particular attention to public health. It has been an urgent necessity to exploit reliable imaging strategies for lipids and thus to monitor fatty liver diseases. Herein, by converting the NIR-I signal to the NIR-II signal with IR1061 for the monitoring of lipid, the in vivo imaging of fatty liver disease was promoted on the contrast and visual effect. The main advantages of the imaging promotion in this work included a long emission wavelength, rapid response, and high signal-background-ratio (SBR) value. After promoting the NIR-I signal to NIR-II signal, IR1061 achieved higher SBR value and exhibited a dose-dependent fluorescence intensity at 1100 nm along with the increase of the EtOH proportion as well as steady and selective optical responses toward liposomes. IR1061 was further applied in the in vivo imaging of lipid in fatty liver diseases. In spite of the differences in body weight gain and TC level between healthy mice and fatty liver diseases two models, IR1061 achieved high-resolution imaging in the liver region to monitor the fatty liver disease status. This work might be informatic for the clinical diagnosis and therapeutical treatments of fatty liver diseases.

Potassium sodium hydrogen citrate intervention on gut microbiota and clinical features in uric acid stone patients.

The high recurrence rate of renal uric acid stone (UAS) poses a significant challenge for urologists, and potassium sodium hydrogen citrate (PSHC) has been proven to be an effective oral dissolution drug. However, no studies have investigated the impact of PSHC on gut microbiota and its metabolites during stone dissolution therapy. We prospectively recruited 37 UAS patients and 40 healthy subjects, of which 12 patients completed a 3-month pharmacological intervention. Fasting vein blood was extracted and mid-stream urine was retained for biochemical testing. Fecal samples were collected for 16S ribosomal RNA (rRNA) gene sequencing and short chain fatty acids (SCFAs) content determination. UAS patients exhibited comorbidities such as obesity, hypertension, gout, and dyslipidemia. The richness and diversity of the gut microbiota were significantly decreased in UAS patients, Bacteroides and Fusobacterium were dominant genera while Subdoligranulum and Bifidobacterium were poorly enriched. After PSHC intervention, there was a significant reduction in stone size accompanied by decreased serum uric acid and increased urinary pH levels. The abundance of pathogenic bacterium Fusobacterium was significantly downregulated following the intervention, whereas there was an upregulation observed in SCFA-producing bacteria Lachnoclostridium and Parasutterella, leading to a significant elevation in butyric acid content. Functions related to fatty acid synthesis and amino acid metabolism within the microbiota showed upregulation following PSHC intervention. The correlation analysis revealed a positive association between stone pathogenic bacteria abundance and clinical factors for stone formation, while a negative correlation with SCFAs contents. Our preliminary study revealed that alterations in gut microbiota and metabolites were the crucial physiological adaptation to PSHC intervention. Targeted regulation of microbiota and SCFA holds promise for enhancing drug therapy efficacy and preventing stone recurrence. KEY POINTS: • Bacteroides and Fusobacterium were identified as dominant genera for UAS patients • After PSHC intervention, Fusobacterium decreased and butyric acid content increased • The microbiota increased capacity for fatty acid synthesis after PSHC intervention.

A structural optimized fluorescent probe for monitoring hydrogen sulfide in cells and zebrafish.

In this work, we reported a fluorescent probe Fur-SH, a derivative of benzofuranone, which was used to detect H2S in living cells and zebrafish. Based on the three structural characteristics of the probe, the effects of different structural modifications on the optical properties of the fluorophore were compared. Then, the fluorophore Fur-OH was synthesized by modifying diethylamino group with benzofuranone as the main skeleton. With 2,4-dinitrofluorobenzene as the recognition group and diethylamino as the electron donor, the push-pull electron effect occurred with nitro group, which led to fluorescence quenching, and an openable fluorescent probe Fur-SH was formed. The probe Fur-SH (λex = 510 nm; λem = 570 nm) had the advantages of smaller full width at half maxima, rapid response (5 min) and wide pH window. The quantitative properties of the probe were excellent, reaching saturation at 50 equivalents of substrate. The probe Fur-SH showed high sensitivity to H2S, with LOD of 48.9 nM and LOQ of 50 nM. At present, the probe Fur-SH had been applied to fluorescence imaging of MCF-7 cells and zebrafish. By comparing the effects of different structures on the optical properties of fluorophores, this work was expected to be helpful to the development of fluorescent probes in the future.

A human serum albumin-binding-based fluorescent probe for monitoring hydrogen sulfide and bioimaging.

In this work, a fluorescent probe, TPABF-HS, was developed for detecting hydrogen sulfide (H2S) using a human serum albumin (HSA)-binding-based approach for amplifying the fluorescence signal and extending the linear correlation range. Compared to the most recent probes for H2S, the most interesting feature of the detection system developed herein was the especially wide linear range (0-1000 µM (0-100 eq.)), which covered the physiological and pathological levels of H2S. TPABF-HS could be used in applications high sensitivity and selectivity with an LOD value of 0.42 µM. Further, site-competition experiments and molecular docking simulation experiments indicated that signal amplification was realized by the binding of the TPABF fluorophore to the naproxen-binding site of HSA. Moreover, the extension of the measurement span could allow for applications in living cells and Caenorhabditis elegans for imaging both exogenous and endogenous H2S. This work brings new information to the strategy of signal processing by exploiting fluorescent probes.

Fluorescence probe for real-time malonaldehyde detection in epilepsy model.

Oxidative stress, a condition involving an imbalance between reactive oxygen species (ROS) and antioxidants, is closely linked to epilepsy, contributing to abnormal neuronal excitability. This study introduces a novel fluorescent probe, the MDP probe, designed for the efficient detection of malondialdehyde (MDA), a critical biomarker associated with oxidative stress. The MDP probe offers several key advantages, including high sensitivity with a low detection limit of 0.08 µM for MDA, excellent selectivity for MDA even in the presence of interfering substances, and biocompatibility, making it suitable for cell-based experiments. The probe allows for real-time monitoring of MDA levels, enabling dynamic studies of oxidative stress. In vivo experiments in mice demonstrate its potential for monitoring MDA levels, particularly in epilepsy models, which could have implications for disease research and diagnosis. Overall, the MDP probe represents a promising tool for studying oxidative stress, offering sensitivity and specificity in cellular and in vivo settings. Its development opens new avenues for exploring the role of oxidative stress in various biological processes and diseases, contributing to advancements in healthcare and biomedical research.

Comparative Analysis of Super-Mini Percutaneous Nephrolithotomy Combined with Flexible Ureteroscopic Lithotripsy versus Flexible Ureteroscopic Lithotripsy Alone for Treating Complex Kidney Stones: A Retrospective Study of 205 Patients.

BACKGROUND This retrospective study aimed to compare outcomes from super-mini percutaneous nephrolithotomy (SMP) combined with flexible ureteroscopic lithotripsy (FURL) and FURL alone in 205 patients with 2.5-4.2 cm diameter complex kidney stones. MATERIAL AND METHODS Between January 2018 and December 2022, 92 patients were treated with SMP combined with FURL (group A), and 113 patients were treated with FURL alone (group B). The stone-free rate (SFR), retreatment ratio, operation time, mean decline in hemoglobin level, postoperative pain visual analogue scale (VAS), and postoperative hospitalization time and complications were analyzed and compared between the 2 groups. RESULTS The SFR 3 days after the operation was 85.87% in group A, which was significantly higher than that in group B (72.57%) (P=0.021). The rate of retreatment in group A (3.26%) was significantly lower than that in group B (10.62%) (P=0.044). The SFR after 90 days was higher in group A (94.57%) than in group B (90.27%) (P=0.254). The mean decrease in hemoglobin, postoperative hospitalization duration, and VAS score 6 hours after the operation were all significantly higher in group A than in group B (P<0.05). However, there was no significant difference in operation time, VAS score at 12 and 24 hours after the operation, and complication rate. CONCLUSIONS In the treatment of complex renal stones, compared with FURL, SMP combined with FURL in the oblique supine lithotomy position has the advantages of a higher early SFR with no increased risk of complications.

Near-infrared imaging of hepatocellular carcinoma and its medicinal treatment with a γ-glutamyl transpeptidase-monitoring fluorescence probe.

Herein, the Near-infrared imaging of hepatocellular carcinoma (HCC) and its medicinal treatment was achieved with a γ-glutamyl transpeptidase (GGT)-monitoring fluorescence probe KYZ-GGT which consisted of the typical recognition group γ-glutamyl and the structurally modified signal reporting group hemicyanine-thioxanthene. Compared with the recently reported probes, KYZ-GGT suggested practical and steady capability for monitoring the GGT level in the cellular, xenograft, induced as well as medicinal treatment HCC models. It realized the mitochondrial targeting intracellular imaging to reflect the GGT dynamics in the induction or medicinal treatment of HCC. In the xenograft and induced model mice with multiple factors, KYZ-GGT showed stable performance for visualizing the HCC status. In the medicinal treatment of the long-period-induced HCC model mice verified by the serum indexes and histopathological analysis, KYZ-GGT successfully imaged the medicinal treatment process of HCC with two marketed drugs (Sorafenib and Lenvatinib) respectively, with an applicative penetration depth. The information here was meaningful for investigating effective medicinal strategies for overcoming HCC.

Switchable metasurface for high-efficiency absorption and broadband polarization conversion based on vanadium dioxide in the terahertz frequency.

High-performance devices with superior execution will facilitate the practical application of terahertz (THz) technology and foster THz innovation. In this paper, taking advantage of the phase transition characteristics of vanadium dioxide (V O 2), a reconfigurable metasurface with absorption and polarization conversion capacities is proposed. The metallic condition of V O 2 results in the formation of a wideband absorber. It provides more than 90% absorption over a broad spectral range from 3.32 to 5.30 THz. Due to the regularity of the meta-atom, the absorber is not polarization-delicate and keeps a high retention rate in the scope of incoming angles from 0° to 45°. When V O 2 is in the insulating condition, the calculated outcomes demonstrate that the cross-polarization conversion rate can reach more than 90% in the range of 2.29-7.85 THz when x-polarized or y-polarized waves are incident vertically. The proposed metasurface is likely to be used in the fields of emitters, sensors, imaging systems, and wireless communication.

Molecular simulations required to target novel and potent inhibitors of cancer invasion.

INTRODUCTION: Computer-aided drug design (CADD) is a computational approach used to discover, develop, and analyze drugs and active molecules with similar biochemical properties. Molecular simulation technology has significantly accelerated drug research and reduced manufacturing costs. It is an optimized drug discovery method that greatly improves the efficiency of novel drug development processes. AREASCOVERED: This review discusses the development of molecular simulations of effective cancer inhibitors and traces the main outcomes of in silico studies by introducing representative categories of six important anticancer targets. The authors provide views on this topic from the perspective of both medicinal chemistry and artificial intelligence, indicating the major challenges and predicting trends. EXPERT OPINION: The goal of introducing CADD into cancer treatment is to realize a highly efficient, accurate, and desired approach with a high success rate for identifying potent drug candidates. However, the major challenge is the lack of a sophisticated data-filtering mechanism to verify bottom data from mixed-quality references. Consequently, despite the continuous development of algorithms, computer power, and interface optimization, specific data filtering mechanisms will become an urgent and crucial issue in the future.

Recent Advances in Xanthine Oxidase Inhibitors.

Uric acid is a product of purine nucleotide metabolism, and high concentrations of uric acid can lead to hyperuricemia, gout and other related diseases. Xanthine oxidase, the only enzyme that catalyzes xanthine and hypoxanthine into uric acid, has become a target for drug development against hyperuricemia and gout. Inhibition of xanthine oxidase can reduce the production of uric acid, so xanthine oxidase inhibitors are used to treat hyperuricemia and related diseases, including gout. In recent years, researchers have obtained new xanthine oxidase inhibitors through drug design, synthesis, or separation of natural products. This paper summarizes the research on xanthine oxidase inhibitors since 2015, mainly including natural products, pyrimidine derivatives, triazole derivatives, isonicotinamide derivatives, chalcone derivatives, furan derivatives, coumarin derivatives, pyrazole derivatives, and imidazole derivatives, hoping to provide valuable information for the research and development of novel xanthine oxidase inhibitors.

3D dynamic tracking Aß plaques in live brains using vinyl-bridged dyes with two-photon excitation/NIR emission and large Stokes shifts.

Real-time studies of biomarkers for neurological disorders present significant opportunities for diagnosing and treating related diseases, and fluorescent probes offer a promising approach to brain imaging. However, intracerebral fluorescence imaging is often limited by blood-brain barrier permeability and penetration depth. Moreover, only very few probes have rapid intracerebral metabolic properties, which are critical for in vivo imaging. Here, we developed a novel class of fluorescent dyes with two-photon excitation and near-infrared (NIR) emission (920/705 nm). The representative WAPP-4 probe exhibits a large Stokes shift (Δλ = 324 nm in ethanol) and excellent blood-brain barrier permeability. Notably, using WAPP-4, we achieved in vivo 3D dynamic imaging of Aß plaques in the brains of living mice with Alzheimer's disease (AD). In addition, super-resolution imaging showed that WAPP-4 could effectively characterize the distribution and shape of Aß plaques in isolated brain slices. This study demonstrates that newly developed fluorescent dyes with large Stokes shifts and blood-brain barrier permeability enable real-time imaging of amyloid plaques, which will contribute to the development of other valuable tools for near-infrared imaging and super-resolution imaging in the brain.

Imaging Investigation of Hepatocellular Carcinoma Progress via Monitoring γ-Glutamyltranspeptidase Level with a Near-Infrared Fluorescence/Photoacoustic Bimodal Probe.

Hepatocellular carcinoma (HCC) is one of the main principal causes of cancer death, and the late definite diagnosis limits therapeutic approaches in time. The early diagnosis of HCC is essential, and the previous investigations on the biomarkers inferred that the γ-glutamyltranspeptidase (GGT) level could indicate the HCC process. Herein, a near-infrared fluorescence/photoacoustic (NIRF/PA) bimodal probe, CySO3-GGT, was developed for monitoring the GGT level and thus to image the HCC process. After the in-solution tests, the bimodal response was convinced. The various HCC processes were imaged by CySO3-GGT at the cellular level. Then, the CCl4-induced HCC (both induction and treatment) and the subcutaneous and orthotopic xenograft mice models were selected. All throughout the tests, CySO3-GGT achieved NIRF and PA bimodal imaging of the HCC process. In particular, CySO3-GGT could effectively realize 3D imaging of the HCC nodule by visualizing the boundary between the tumor and the normal tissue. The information here might offer significant guidance for the dynamic monitoring of HCC in the near future.