Zinc and Inflammatory Bowel Disease: From Clinical Study to Animal Experiment.

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract (GI) with a high incidence rate globally, and IBD patients are often accompanied by zinc deficiency. This review aims to summarize the potential therapeutic value of zinc supplementation in IBD clinical patients and animal models. Zinc supplementation can relieve the severity of IBD especially in patients with zinc deficiency. The clinical severity of IBD were mainly evaluated through some scoring methods involving clinical performance, endoscopic observation, blood biochemistry, and pathologic biopsy. Through conducting animal experiments, it has been found that zinc plays an important role in alleviating clinical symptoms and improving pathological lesions. In both clinical observation and animal experiment of IBD, the therapeutic mechanisms of zinc interventions have been found to be related to immunomodulation, intestinal epithelial repair, and gut microbiota's balance. Furthermore, the antioxidant activity of zinc was clarified in animal experiment. Appropriate zinc supplementation is beneficial for IBD therapy, and the present evidence highlights that alleviating zinc-deficient status can effectively improve the severity of clinical symptoms in IBD patients and animal models.

Synthetic molecular switches driven by DNA-modifying enzymes.

Taking inspiration from natural systems, in which molecular switches are ubiquitous in the biochemistry regulatory network, we aim to design and construct synthetic molecular switches driven by DNA-modifying enzymes, such as DNA polymerase and nicking endonuclease. The enzymatic treatments on our synthetic DNA constructs controllably switch ON or OFF the sticky end cohesion and in turn cascade to the structural association or disassociation. Here we showcase the concept in multiple DNA nanostructure systems with robust assembly/disassembly performance. The switch mechanisms are first illustrated in minimalist systems with a few DNA strands. Then the ON/OFF switches are realized in complex DNA lattice and origami systems with designated morphological changes responsive to the specific enzymatic treatments.

Accurate intracellular and in vivo temperature sensing based on CuInS2/ZnS QD micelles.

Accurate and sensitive temperature sensing is of great importance for studying biological activities in cells and tissues. Due to the complexity of the microenvironments, most of the existing thermometry systems cannot meet the needs of accurate intracellular and in vivo temperature sensing with high-sensitivity and low-toxicity. After investigation, we found that the fluorescence intensity of CuInS2/ZnS quantum dots (QDs) is significantly temperature dependent, and these QDs can be used for intracellular and in vivo temperature sensing after being encapsulated by amphiphilic micelles (QD-micelles). These QD-micelles have a size of approximately 10.1 ± 2.5 nm and an emission band of approximately 650 nm with intense photoluminescence (PL). Meanwhile, its high thermal sensitivity of 2% °C-1 at near-room temperature is insensitive to solution pH, ionic strength, and protein concentration. Even at a concentration of 300 µg mL-1, our QD-micelles do not exert cytotoxic effects on HeLa and PC-3 cells. Similar to being dispersed in water, the QD-micelles continue to exhibit a high thermal sensitivity of 2.0% °C-1 intracellular and 2.1% °C-1 in tumor tissues, and the PL intensity (I) and temperature (T) over the physiological temperature range have a good linear correlation. Therefore, they have considerable potential in biomedical applications.