To reduce the side effects of chemotherapy, nontoxic prodrugs activated by the tumor microenvironment are urgently required for use in cancer treatment. In this work, we developed prodrug 4 for tumor-targeting treatment and imaging of the anticancer drug release in vivo. Taking advantage of the high glutathione (GSH) concentration in cancer cells, the disulfide bond in prodrug 4 was cleaved, resulting in the release of an active anticancer drug and a near-infrared (NIR) fluorescence dye turn-on. Furthermore, contrast to the free anticancer drug, the prodrug exhibited higher cytotoxicity to hepatoma cells than that to normal HL-7702 cells. Thus, prodrug 4 is a promising platform for specific tumor-activatable drug delivery system, because of its favorable features of in situ and in vivo monitoring of the drug release and therapeutic efficacy.

Alterations of cellular redox status are closely associated with physiological and pathological processes.Glutathione (GSH) and H 2 O 2 should be the most representative redox couple in living cells. However, up to now, there is no way to reversibly detect GSH/H 2 O 2 . In this report, a near-infrared (NIR) fluorescent probe (Cy-O-Eb) for monitoring the changes of GSH/H 2 O 2 levels in vivo was developed based on switching on-off a five-membered ring involved in ebselen. This probe could reversibly respond to GSH and H 2 O 2 with high selectivity, sensitivity and mitochondrial targeting. It was successfully used to monitor the changes of redox status during apoptosis and the H 2 O 2 changes at the wound margin in zebrafish larvae. Thus, the probe would provide an ideal tool for monitoring redox status changes and studying molecular events involved in redox regulation.

A highly selective and sensitive near-infrared (NIR) fluorescence probe (Cy-NO2) for imaging nitroreductase was developed and was successfully applied to investigating the relationship between epithelial-mesenchymal transitions (EMTs) in tumour progression and intracellular hypoxic level.

Gold nanoparticles (Au NPs) assembled through Au-S covalent bonds have been widely used in biomolecule-sensing technologies. However, during the process, detection distortions caused by high levels of thiol compounds can still significantly influence the result and this problem has not really been solved. Based on the higher stability of Au-Se bonds compared to Au-S bonds, we prepared selenol-modified Au NPs as an Au-Se nanoplatform (NPF). Compared with the Au-S NPF, the Au-Se NPF exhibits excellent anti-interference properties in the presence of millimolar levels of glutathione (GSH). Such an Au-Se NPF that can effectively avoid detection distortions caused by high levels of thiols thus offers a new perspective in future nanomaterial design, as well as a novel platform with higher stability and selectivity for the in vivo application of chemical sensing and clinical therapies.

Activating transcription factor 2 (ATF2) is a member of the leucine zipper family of DNA-binding proteins and is widely distributed in tissues including the liver, lung, spleen, and kidney. Like c-Jun and c-Fos, ATF2 responds to stress-related stimuli and may thereby influence cell proliferation, inflammation, apoptosis, oncogenesis, neurological development and function, and skeletal remodeling. Recent studies clarify the regulatory role of ATF2 in inflammation and describe potential inhibitors of this protein. In this paper, we summarize the properties and functions of ATF2 and explore potential applications of ATF2 inhibitors as tools for research and for the development of immunosuppressive and anti-inflammatory drugs.