A near-infrared fluorescent probe for tracking endogenous and exogenous H2O2 in cells and zebrafish.

H2O2 is an important signaling molecule in the body, and its levels fluctuate in many pathological sites, therefore, it can be used as a biomarker for early diagnosis of disease. Since the environment in vivo is extremely complex, it is of great significance to develop a probe that can accurately monitor the fluctuation of H2O2 level without interference from other physiological processes. Based on this, we designed and synthesized two new near-infrared H2O2 fluorescent probes, LTA and LTQ, based on the ICT mechanism. Both of them have good responses to H2O2, but LTA has a faster response speed. In addition, the probe LTA has good biocompatibility, good water solubility, and a large Stokes shift (95 nm). The detection limit is 4.525 µM. The probe was successfully used to visually detect H2O2 in living cells and zebrafish and was successfully used to monitor the changes in H2O2 levels in zebrafish due to APAP-induced liver injury.

Visualize intracellular ß-galactosidase using an asymmetric near-infrared fluorescent probe with a large Stokes shift.

ß-galactosidase (ß-Gal) is an important biomarker of cell senescence and primary ovarian cancer. Therefore, it is of great significance to construct a near-infrared fluorescent probe with deep tissue penetration and a high signal-to-noise ratio for visualization of ß-galactosidase in biological systems. However, most near-infrared probes tend to have small Stokes shifts and low signal-to-noise ratios due to crosstalk between excitation and emission spectra. Using d-galactose residues as specific recognition units and near-infrared dye TJ730 as fluorophores, a near-infrared fluorescence probe SN-CR with asymmetric structure was developed for the detection of ß-Gal. The probe has a fast reaction equilibrium time (<12 min) with ß-Gal, excellent biocompatibility, near-infrared emission (738 nm), low detection limit (0.0029 U/mL), and no crosstalk between the excitation spectrum and emission spectrum (Stokes shifts 142 nm) of the probe. Cell imaging studies have shown that SN-CR can visually trace ß-Gal in different cells and distinguish ovarian cancer cells from other cells.

Design and application of prodrug fluorescent probes for the detection of ovarian cancer cells and release of anticancer drug.

Ovarian cancer is a gynecologic malignancy with high mortality. The main reason is that it is detected at an advanced stage due to a lack of early diagnosis and treatment. Therefore, it is of great interest to develop a chemical tool that can visualize ovarian cancer cells in real-time and eliminate them. Unfortunately, probes that can simultaneously monitor both modes of action for the diagnosis and treatment of ovarian cancer have not been developed. Here, we designed a novel prodrug fluorescent probe (YW-OAc) that not only visually tracks cancer cells but also enables the on-demand delivery of chemotherapeutic agents. By ß-Gal-mediated glycosidic bond hydrolysis, the fluorescent signal changed from blue to green (signal 1), enabling visual tracking of ovarian cancer cells. Subsequently, the identified cancer cells were subjected to precise light irradiation to induce anticancer drug release accompanied by a fluorescence transition from green to blue (signal 2), enabling real-time information on drug release. Thus, the prodrug fluorescent probe YW-OAc provides comprehensive two-step monitoring during cancer cell recognition and clearance. Notably, YW-OAc exhibited high affinity (Km = 3.74 µM), high selectivity, and low detection limit for ß-Gal (0.0035 U/mL). We also demonstrated that YW-OAc can visually trace endogenous ß-Gal in different cells and exhibit high phototoxicity in ovarian cancer cells. We hope that the prodrug fluorescent probe YW-OAc, can be used as an effective tool for biomedical diagnosis and treatment.

Acetyl group assisted rapid intramolecular recognition of hydrogen peroxide: A novel promising approach for efficient hydrogen peroxide probe.

As a vital biomolecule, hydrogen peroxide (H2O2) is involved in many physiological and pathological processes. Therefore, it is important to detect H2O2 in vivo conveniently and efficiently. In this paper, we report a new method of nucleophilic addition of H2O2 to the acetyl group to promote the rapid intramolecular reaction, which can be used to develop an efficient H2O2 probe. Based on this unique auxiliary recognition part, a fluorescent probe for H2O2 detection was designed and synthesized. This probe has the advantages of high sensitivity (limits of detection 7.0 × 10-8 M or even lower.), fast response (within 3 min) and large Stokes shift (225 nm), which not only can monitor exogenous and endogenous H2O2 in cells but also successfully achieves the change of endogenous H2O2 level caused by drug sexual organ injury in zebrafish.

Automatic Recognition of Ocular Surface Diseases on Smartphone Images Using Densely Connected Convolutional Networks.

Ocular surface disorder is one of common and prevalence eye diseases and complex to be recognized accurately. This work presents automatic classification of ocular surface disorders in accordance with densely connected convolutional networks and smartphone imaging. We use various smartphone cameras to collect clinical images that contain normal and abnormal, and modify end-to-end densely connected convolutional networks that use a hybrid unit to learn more diverse features, significantly reducing the network depth, the total number of parameters and the float calculation. The validation results demonstrate that our proposed method provides a promising and effective strategy to accurately screen ocular surface disorders. In particular, our deeply learned smartphone photographs based classification method achieved an average automatic recognition accuracy of 90.6%, while it is conveniently used by patients and integrated into smartphone applications for automatic patient-self screening ocular surface diseases without seeing a doctor in person in a hospital.