Amphiphilic Rhodamine Fluorescent Probes Combined with Basal Imaging for Fine Structures of the Cell Membrane.

Confocal fluorescence imaging of fine structures of the cell membrane is important for understanding their biofunctions but is often neglected due to the lack of an effective method. Herein, we develop new amphiphilic rhodamine fluorescent probe RMGs in combination with basal imaging for this purpose. The probes show high signal-to-noise ratio and brightness and low internalization rate, making them suitable for imaging the fine substructures of the cell membrane. Using the representative probe RMG3, we not only observed the cell pseudopodia and intercellular nanotubes but also monitored the formation of migrasomes in real time. More importantly, in-depth imaging studies on more cell lines revealed for the first time that hepatocellular carcinoma cells secreted much more adherent extracellular vesicles than other cell lines, which might serve as a potential indicator of liver cells. We believe that RMGs may be useful for investigating the fine structures of the cell membrane.

Specific Spleen-Accumulated NIR-II Fluorescent Probe for Imaging-Guided Splenic Operation.

Spleen is a large immune organ in the body. Splenic operations such as splenectomy and intrasplenic injection are of paramount importance for immunological research and splenic diseases. Fluorescence imaging can vastly simplify these operations, but a specific spleen-targeting probe is still unavailable. Herein, the first specific spleen-accumulated fluorescent probe, VIX-S is reported, which fluoresces at 1064 nm and is highly stable. Systematic studies reveal the superior targeting and imaging performance of VIX-S for the spleen in both nude and haired mice. In vivo imaging indicates that the probe can image the morphology of spleen with a signal-background ratio of at least two-fold higher than that of the liver. Moreover, the application of VIX-S in imaging-guided splenic operation, including splenic injury and intrasplenic injection, is demonstrated, which may provide a practice tool for spleen research in the animal model.

Big Data Analysis of Manufacturing and Preclinical Studies of Nanodrug-Targeted Delivery Systems: A Literature Review.

Objective: Nanodelivery is a modern technology involving improved delivery methods and drug formulations. The current development and initial applications of nanocarriers are pointing to new directions in the current development of nanomedicine. Researchers are increasingly applying nanodelivery to the delivery of therapeutic or diagnostic agents. This article discusses the preparation and application of nanocomplexes and nanoparticles, as well as their potential future value in clinical research. Through a review and analysis, it is hoped that this will serve as a guide for the future development of various nanodelivery technologies and help researchers learn more about these technologies. Materials and Methods: A literature search was conducted using the keywords "Nano drug delivery" or "Nanomedical materials" or "Nano". A literature search was conducted in three major databases, PubMed, Web of Science, and Google Scholar, using the keywords such as "Nano drug delivery", "Nanomedical materials", or "Nanobubble drug delivery". The initial search was screened by title and abstract. In the full-text review, the titles or abstracts were reviewed according to the selection criteria based on the inclusion criteria. The risk of bias and study quality was assessed according to the Cochrane guidelines, and possible biases such as selection bias and good selection bias were included in the review. Results: A total of 297 studies were included in this study, of which 219 were excluded based on the screening criteria, resulting in the inclusion of 78 studies, the majority of which were original studies and clinical trials, and a small number of which provided design and route of administration analysis of nanomaterial particles and effect fluorograms and were studied in more depth. This paper summarises and reviews the views and directions of the included articles. The main directions include cyclodextrin-based or grafted cyclodextrin nanomaterials, nanobubbles, and stimuli-sensitive and temperature-sensitive nanodelivery systems. Conclusion: The use of innovative, targeted drug delivery systems is effective in cancer drug delivery by summarising the previous studies. However, nanodelivery systems' risks and therapeutic effects need to be evaluated before clinical application. Future research in the field of targeted drug delivery nanosystems should focus on the development of nanocarriers with high in vivo delivery capacity, good synergy with therapeutic agents, and milder short-term and long-term toxicological effects and conduct comprehensive preclinical trials on nanodrug delivery systems with high potential for clinical application as soon as possible, to find nanodrug delivery systems suitable for clinical use and put them into the clinical application as soon as possible.

New fluorescent probe with recognition moiety of bipiperidinyl reveals the rise of hepatocellular carboxylesterase activity during heat shock.

Heat shock is a heat-related pathology characterized by a high body temperature and an obvious change of many enzymatic activities. Carboxylesterase (CE), as the major hydrolase in liver, is responsible for the hydrolysis of many drugs or the detoxification of various toxins from all organs. However, the correlation between heat shock and the CE activity in cells remains unknown, mainly due to the lack of a suitable research approach. Herein, a new water-soluble fluorescence probe, MYO-CE, with a specific bipiperidinyl recognition moiety has been developed for detecting the CE activity. MYO-CE reacted selectively with CE instead of other esterase, causing a large fluorescence off-on response at 560 nm with a detection limit of 0.39 U/mL. The applicability of MYO-CE for cell imaging was demonstrated by monitoring the alteration of the hepatocellular CE activity under inflammation. More importantly, we investigated the change of the CE activity during heat shock, uncovering a significant increase for the first time. This finding was further validated by a commercial colorimetric kit assay. The proposed probe shows a promising prospect for the CE study in cells under different pathological conditions.

Dual-Colored Fluorescence Imaging of Mitochondrial HNO and Golgi-HNO in Mice with DILI.

Drug-induced liver injury (DILI) is the most common reason for the post-marketing withdrawal of drugs. Poor understanding of the mechanisms of DILI presents a large challenge in clinical diagnosis. Previous evidences indicate a potential relationship between reactive nitrogen species (RNS) and DILI. Hence, we developed two specific probes, Golgi-HNO and Mito-HNO, for the multicolored and simultaneous in situ imaging of nitroxyl (HNO) in the Golgi apparatus and mitochondria, respectively. We discovered a significant rise in HNO levels in the livers of mice with DILI, which means that for the first time, we revealed a positive correlation between HNO levels and DILI. Based on changes in the HNO level, we also successfully explored the extent of liver damage induced by an anticarcinogen, bleomycin. In addition, we uncovered catalase was involved in HNO synthesis, which is the unprecedented function of catalase. These findings demonstrate that HNO is an ideal biomarker for DILI diagnosis, and Golgi-HNO and Mito-HNO are ideal fluorescent probes to study in situ HNO changes in various physiological and biochemical processes.

In situ photoacoustic imaging of cysteine to reveal the mechanism of limited GSH synthesis in pulmonary fibrosis.

We developed a photoacoustic and fluorescent dual-mode imaging probe, CCYS, for the detection of cysteine with high selectivity and sensitivity in a living system for the first time. By using CCYS, we found that the limited synthesis of glutathione in pulmonary fibrosis was not caused by cysteine deficiency.

Fluorescent Imaging for Cysteine Detection In Vivo with High Selectivity.

As an essential amino acid, cysteine is involved in various biosynthetic and metabolic processes, such as protein synthesis, hormone synthesis, and redox homeostatic maintenance. Inordinate cysteine levels are often associated with serious diseases. Thus, designing and synthesizing a novel fluorescent probe for determining the concentration of cellular cysteine, which could indirectly monitor the prevalence of these diseases, is essential. We developed a florescence probe P-Cy with good sensitivity for cysteine detection in vivo. P-Cy only exhibited good response toward cysteine but did not show response toward other biothiols, such as homocysteine (Hcy) and glutathione (GSH). In this study, we used P-Cy by successfully imaging cellular endogenous and exogenous cysteine levels. Furthermore, P-Cy was also performed in mice to detect cysteine level, indicating that P-Cy is a powerful tool for cysteine detection in situ.

In Vivo Two-Photon Fluorescence Imaging of the Activity of the Inflammatory Biomarker LTA4H in a Mouse Pneumonia Model.

Severe atmospheric haze caused by industrial pollution has severely affected human health and led to the increasing incidence of cardiopulmonary diseases, including pneumonia. Conventional methods for diagnosis of pneumonia are complicated and tedious, and current clinical imaging techniques might cause organ injuries to some extent. Therefore, an accurate, fast, and intact imaging method must be developed to diagnose pneumonia in the early stages. In this study, we propose a new two-photon fluorescence probe, named as ASPC, for detection of the activity of the inflammatory biomarker LTA4H through specific recognition and cleavage of amides containing the unnatural amino acid l-AspBzl. The activity of LTA4H in the lung tissues of mice was rapidly and accurately monitored for the first time and could be an indicator for diagnosis of pneumonia. The severity of pneumonia in mice caused by haze particulate was determined through imaging the activity of LTA4H as biomarker and confirmed using a commercial ELISA kit of interleukin-1ß. This work provides a promising method for clinical detection of pneumonia and for screening specific depressors of LTA4H as potential drug candidates.