Design, synthesis and evaluation of liver-targeting fluorescent probes for detecting mercury ions

Tackling the water solubility dilemma of spiroring-closing rhodamine: Sulfone-functionalization enabling rational designing water-soluble probe for rapid visualizing mercury ions in cosmetics

Rhodamine derivatives possessing spiroring-closing structures exhibit colorlessness, while the induction of spiroring-opening by metal ions results in notable color changes, rendering them as ideal platform for the development of functional probes with broad applications. However, the spiroring-closing form of rhodamine-based probes exhibits limited water solubility due to its neutral character, necessitating the incorporation of organic solvents to enhance solubility, which may adversely affect the natural system. Designing rhodamine probes with high solubility in both the zwitterionic and neutral form is of utmost importance and presents a significant challenge. This study presents a sulfone-rhodamine-based probe that exhibits good water solubility both in the spiroring opening and closing for detecting Hg2+. Upon the presence of Hg2+, the color undergoes a noticeable change from colorless to pink, with a response time of less than 1 min. probe 1 demonstrates an excellent linear relationship with Hg2+ concentrations within the range of 0-8 μM, and achieves a detection limit is 17.26 nM. The effectiveness of probe 1 was confirmed through the analysis of mercury ions in cosmetic products. Utilizing this probe, test paper strips have been developed to enhance the portability of Hg2+ detection naked eyes.

Research progress on asialoglycoprotein receptor-targeted radiotracers designed for hepatic nuclear medicine imaging

Asialoglycoprotein receptor (ASGPR) specifically recognizes glycans terminated with β-d-galactose or N-acetylgalactosamine. Its exclusive expression in mammalian hepatocytes renders it an ideal hepatic-targeted biomarker. To date, ASGPR-targeted ligands have been actively developed for drug delivery and hepatic imaging. This review provides a comprehensive summary of the progress achieved to-date in the field of developing ASGPR-targeted nuclear medicine imaging (NMI) radiotracers, highlighting the recent advancements over the last decade in terms of structure, radionuclides and labeling strategies. The biodistribution patterns, imaging characteristics, challenges and future prospective are discussed.

Fine-tuning bromide AIE probes for Hg2+ detection in mitochondria with wash-free staining

Mercury ions (Hg2+) primarily target mitochondria in the cells. Therefore, the development of novel probes that specifically target mitochondria in the presence of Hg2+ is of immense importance. Most previously reported probes that utilize the softness of S, Te, O, and/or N atoms for Hg2+ binding often face problems such as fluorescence quenching and off-target signals. In this study, bromide-hydrocarbon pyridinium salts were designed to target the mitochondria and chelate Hg2+ via Hg-Br coordination bonds. As a prototype, four aggregation-induced emission (AIE) fluorogens, namely TPP-Br, TPP-Cl, R1, and R2, with a similar D-π-A structure but slight differences in their halogen substituents, were designed. Among them, only TPP-Br achieved the highly selective and sensitive detection of Hg2+ by triggering its AIE properties, resulting in remarkable emission enhancement (80-fold), colorimetry, and the Tyndall effect. TPP-Br exhibited high selectivity and sensitivity to Hg2+ with a detection limit of 0.35 μM, rapid response time (<10 s), and large Stokes shift of 185 nm. Their interaction modes were studied using a combination of 1H nuclear magnetic resonance spectroscopy, scanning electron microscopy, fluorescent lifetime decay, and theoretical calculations. TPP-Br exhibited a low emission background in cells, whereas in the presence of Hg2+, mitochondria were lit up with wash-free staining. This study provides a powerful tool for accurately diagnosing mercury poisoning-related diseases in mitochondria.

Recent Advances in Drug Release, Sensing, and Cellular Uptake of Ring-Opening Metathesis Polymerization (ROMP) Derived Poly(olefins)

The synthesis and applications of ring-opening metathesis polymerization (ROMP) derived poly(olefins) have emerged as an exciting area of great interest in the field of biomaterials science. The major focus of this mini-review is to present recent advances in the synthesis of functional materials using ROMP-derived poly(olefins) utilized for drug release, sensing, and cellular uptake in the past seven years (2015-2022). This review reveals that materials synthesized by ROMP-derived well-defined functional poly(olefins) stand to be highly promising systems for medical as well as biological studies. Thus, this review may prove to be beneficial for the design and development of new smart and flexible-functionality ROMP-based polymeric materials for various biological applications.