BACKGROUND: Aquaporin-1 (AQP1) protein plays a crucial role in intracellular and extracellular water homeostasis and fluid transport in organs and tissues associated with diverse life activities and is extremely abundant in the kidney. Accurate detection of AQP1 in urine can be applied as screening of early-stage disease. Application of magnetic preconcentration and probe-based signal amplification strategy coupling to inductively coupled plasma mass spectrometry (ICP-MS) is a more accurate, sensitive and specific detection method for AQP1 in complex biological samples compared to conventional methods.
RESULTS: We described an element-labelling strategy based on magnetic preconcentration and probe-based immunoassay coupling to ICP-MS detection. The magnetic beads (MBs) modified with epoxy groups were capable of enriching AQP1 proteins and separating them from complex matrices. The probe constructed by conjugating anti-AQP1 antibody molecules on the surface of gold nanoparticles could specifically recognize AQP1 proteins attached on MBs and be analyzed by ICP-MS. The concentration of AQP1 protein could be precisely quantified and amplified by 14,000 times through the corresponding signal of Au atoms. This assay for AQP1 protein quantification achieved a detection limit down to 0.023 ng mL-1, a broad linear calibration curve between 0.3 ng mL-1 and 30 ng mL-1, as well as outstanding specificity.
CONCLUSIONS: The proposed method was successfully applied to detect AQP1 protein in human urine samples, showing the potential for its applications concerning accurate AQP1 quantification. It can also screen a wide range of proteins provided the antibodies specific to these target proteins are available.

This study investigates the influence of pregnancy on the in vivo activity of the intestinal P-glycoprotein (P-gp) and hepatic organic anion transporters polypeptide (OATP/BCRP) using, respectively, fexofenadine and rosuvastatin as probe drugs. Eleven healthy participants were investigated during the third trimester of pregnancy (Phase 1, 28 to 38 weeks of gestation) and in the postpartum period (Phase 2, 8 to 12 weeks postpartum). In both phases, after administration of a single oral dose of fexofenadine (60 mg) and rosuvastatin (5 mg), serial blood samples were collected for up to 24 h. Rosuvastatin and fexofenadine in plasma were analyzed by LC-MS/MS using previously validated methods. The pharmacokinetic parameters of fexofenadine and rosuvastatin (Phoenix WinNonLin software) with normal distribution (Shapiro-Wilk test) are presented as geometric mean and 90% confidence interval. Phases 1 and 2 were compared using the t test (P < .05). Fexofexadine AUC0-24 values do not differ (P-value: .0715) between Phase 1 (641.9 ng h/mL [500.6-823.1]) and Phase 2 (823.8 ng h/mL [641.5-1057.6]) showing that pregnancy (third trimester) does not alter intestinal P-gp activity. However, rosuvastatin AUC0-24 values are higher (P-value: .00005) in Phase 1 (18.7 ng h/mL [13.3-26.4]) when compared to Phase 2 (9.5 ng h/mL [6.7-13.4]), suggesting inhibition of OATP1B1/OATP1B3 transporters. In conclusion, pregnancy assessed during the third trimester does not alter the intestinal P-gp activity but reduces the activity of hepatic OATP1B1/OATP1B3 transporters. Therefore, adjustments in dosage regimens may be necessary for drugs with low therapeutic index, substrates of the OATP1B1/OATP1B3 transporters, administered during the third trimester of pregnancy.

Mitochondria, pivotal organelles crucial for energy generation, apoptosis regulation, and cellular metabolism, have spurred remarkable advancements in targeted material development. This review surveys recent breakthroughs in targeted mitochondrial nanomaterials, illuminating their potential in drug delivery, disease management, and biomedical imaging. This review approaches from various application perspectives, introducing the specific applications of mitochondria-targeted materials in cancer treatment, probes and imaging, and diseases treated with mitochondria as a therapeutic target. Addressing extant challenges and elucidating potential therapeutic mechanisms, it also outlines future development trajectories and obstacles. By comprehensively exploring the diverse applications of targeted mitochondrial nanomaterials, this review aims to catalyze innovative treatment modalities and diagnostic approaches in medical research. STATEMENT OF SIGNIFICANCE: This review presents the latest advancements in mitochondria-targeted nanomaterials for biomedical applications, covering diverse fields such as cancer therapy, bioprobes, imaging, and the treatment of various systemic diseases. The novelty and significance of this work lie in its systematic analysis of the intricate relationship between mitochondria and different diseases, as well as the ingenious design strategies employed to harness the therapeutic potential of nanomaterials. By providing crucial insights into the development of mitochondria-targeted nanomaterials and their applications, this review offers a valuable resource for researchers working on innovative treatment modalities and diagnostic approaches. The scientific impact and interest to the readership lie in the identification of promising avenues for future research and the potential for clinical translation of these cutting-edge technologies.

5H-Benzimidazo[1,2-c]quinazoline-6-thione (BI-QT), was synthesized as a benzimidazole-based probe to detect H2S. BI-QT exhibits a fluorescent \"turn-on\" response in DMSO/H2O (9:1, HEPES 10 mM, pH 7.4) upon the addition of H2S. The BI-QT probe can determine micromolar (0-600 µM) H2S concentrations in aqueous systems, with a detection limit of 1.12 µM. Interestingly, BI-QT exhibited an ultrafast response to H2S, with maximum intensity achieved almost instantly when exposed to H2S. BI-QT is largely unaffected by pH and responds reliably over the wide 4-11 pH range, which highlights its applicability to various physiological scenarios. UV-vis, fluorescence, and 1H NMR spectroscopic analyses investigated the sensing mechanism. The practicality of the probe was demonstrated using water samples and living cells.

Autophagy is important for many physiological processes; and disordered autophagy can contribute to the pathogenesis of a broad range of systemic disorders. C. elegans is a useful model organism for studying the genetics of autophagy, however, current methods for studying autophagy are labor-intensive and not readily amenable to high-throughput procedures. Here we describe a fluorescent reporter, GFP::LGG-1::mKate2, which is useful for monitoring autophagic flux in live animals. In the intestine, the fusion protein is processed by endogenous ATG-4 to generate GFP::LGG-1 and mKate2 proteins. We provide data indicating that the GFP:mKate ratio is a suitable readout for measuring cellular autophagic flux. Using this reporter, we measured autophagic flux in L1 larvae to day 7 adult animals. We show that basal autophagic flux is relatively low during larval development but increases markedly in reproductive adults before decreasing with age. Furthermore, we show that wild-type, eat-2, and daf-2 mutant animals have distinct autophagic flux profiles through post-embryonic development. Finally, we demonstrate the utility of this reporter by performing a high-content small molecule screen to identify compounds that alter autophagic flux in C. elegans.

The hydroxyl radical (OH) is highly reactive and plays a significant role in a number of physiological and pathological processes within biosystems. Aberrant changes in the level of hydroxyl radical are associated with many disorders including tumor, inflammatory and cardiovascular diseases. Thus, detecting reactive oxygen species (ROS) in biological systems and imaging them is highly significant. In this work, a novel fluorescent probe (HR-DL) has been developed, targeting two organelles simultaneously. The probe is based on a coumarin-quinoline structure and exhibits high selectivity and sensitivity towards hydroxyl radicals (OH). When reacting with OH, the hydrogen abstraction process released its long-range π-conjugation and ICT processes, leading to a substantial red-shift in wavelength. This probe has the benefits of good water solubility (in its oxidative state), short response time (within 10 s), and unique dual lysosome/mitochondria targeting capabilities. It has been applied for sensing OH in biosystem and inflammation mice models.

Fluorescent probes with specific and rapid response to fluoride ions are important mediators for detecting fluoride ions in biological systems. In this study, a phenothiazine-based fluorescent probe, PTC, was designed and synthesized, which undergoes cleavage activation and cyclization induced by fluoride ions targeting Si-O bonds. The probe exhibits strong anti-interference properties and reaches peak fluorescence within 5 min, allowing for quantitative detection of fluoride ions content in the concentration range of 0 to 12.5μM, suitable for live cell fluorescence imaging. The research findings suggest its potential application value in biological systems.

H5, H7, and H9 are pivotal avian influenza virus (AIV) subtypes that cause substantial economic losses and pose potential threats to public health worldwide. In this study, a novel triplex fluorescence reverse transcription-loop-mediated isothermal amplification (TLAMP) assay was developed in which traditional LAMP techniques were combined with probes for detection. Through this innovative approach, H5, H7, and H9 subtypes of AIV can be simultaneously identified and differentiated, thereby offering crucial technical support for prevention and control efforts. Three primer sets and composite probes were designed based on conserved regions of the haemagglutinin gene for each subtype. The probes were labelled with distinct fluorophores at their 3\' ends, which were detached to release the fluorescence signal during the amplification process. The detection results were interpreted based on the colour of the TLAMP products. Then, the reaction conditions were optimized, and three primer sets and probes were combined in the same reaction system, resulting in a TLAMP detection assay for the differential diagnosis of AIV subtypes. Sensitivity testing with in vitro-transcribed RNA revealed that the detection limit of the TLAMP assay was 205 copies per reaction for H5, 360 copies for H7, and 545 copies for H9. The TLAMP assay demonstrated excellent specificity, no cross-reactivity with related avian viruses, and 100% consistency with a previously published quantitative polymerase chain reaction (qPCR) assay. Therefore, due to its simplicity, rapidity, sensitivity, and specificity, this TLAMP assay is suitable for epidemiological investigations and is a valuable tool for detecting and distinguishing H5, H7, and H9 subtypes of AIV in clinical samples.

Volatile organic compounds (VOCs) are a class of hazardous gases that are widely present in the atmosphere and cause great harm to human health. In this paper, a ratiometric fluorescent probe (Dye@Eu-MOFs) based on a dye-functionalized metal-organic framework was designed to detect VOCs, which showed high sensitivity and specificity for acetaldehyde solution and vapor. A linear correlation between the integrated fluorescence intensity (I510/I616) and the concentration of acetaldehyde was investigated, enabling a quantitative analysis of acetaldehyde in the ranges of 1 × 10-4~10-5 μL/mL, with a low detection limit of 8.12 × 10-4 mg/L. The selective recognition of acetaldehyde could be clearly distinguished by the naked eye under the excitation of UV light. The potential sensing mechanism was also discussed. Significantly, a molecular logic gate was constructed based on the whole system, and finally, a molecular logic network system for acetaldehyde detection connecting basic and integrated logic operations was realized. This strategy provided an effective guiding method for constructing a molecular-level logic gate for acetaldehyde detection on a simple platform.

In this work, a near-infrared hepatocyte-targeting fluorescence probe TCF-Gal-Cys was developed. The TCF-Gal-Cys exhibited a low detection limit, good sensitivity and selectivity toward Cys. The responsive mechanism of TCF-Gal-Cys was proposed that the acrylate of TCF-Gal-Cys was subsequently attacked by the thiol group and the amino group of Cys, releasing a strong near-infrared fluorescent group. TCF-Gal-Cys displayed a good hepatocyte-targeting capacity and could specifically distinguish hepatocytes from A549, Hela, SGC-7901 cells because the galactose group of TCF-Gal-Cys can be recognized by HepG2 cells overexpressing ASGPR. The TCF-Gal-Cys has achieved excellently imaging performance to Cys in the zebrafish, so TCF-Gal-Cys has potential to be an effective tool to in real time monitor Cys-related diseases in vitro and in vivo.