Synthesis and application of novel N, Si-carbon dots for the ratiometric fluorescent monitoring of the antibiotic balofloxacin in tablets and serum.

A ratiometric fluorescent probe with blue-emission fluorescence based on N, Si-doped carbon dots (N, Si-CDs) for the detection of balofloxacin (BLFX) was synthesized by simple one-pot hydrothermal carbonization using methotrexate and 3-aminopropyltriethoxysilane (APTES) as carbon materials. The obtained N, Si-CDs showed dual-emission band fluorescence characterization at 374 nm and 466 nm. Furthermore, the synthesized N, Si-CD probe exhibited evidence of ratiometric fluorescence emission characteristics (F 466/F 374) toward BLFX along with a decrease in fluorescence intensity at 374 nm and an increase in fluorescence intensity at 466 nm. Based on this probe, a highly sensitive and fast detection method for the analysis of BLFX has been established with a linear range of 1-60 µM and a low detection limit of 0.1874 µM, as well as a rapid response time of 5.0 s. The developed assay has also been successfully applied for the detection of BLFX in tablets and rat serum.

A novel fluorescence ratio probe based on dual-emission carbon dots for highly selective and sensitive detection of chlortetracycline and cell imaging.

The novel dual-emission carbon dots (DECDs) for highly selective and sensitive recognition of chlortetracycline (CTC) and cell imaging were synthesized successfully by one-step synthesis. The obtained DECDs possessed two fluorescence peaks (345 nm and 450 nm) and showed specific response to CTC, resulting in a decrease in fluorescence intensity at 345 nm, a blue shift, and an increase in fluorescence intensity at 450 nm. The obtained DECDs exhibited highly selective response to CTC and not to its analogues, such as tetracycline, doxycycline, and oxytetracycline. Thus, an excellent ratiometric probe for the detection of CTC was fabricated successfully and used for the detection of CTC in real samples with the detection limit (LOD) of 16.45 nM. More importantly, the DECDs were used for quantitative detection of CTC in living cells, which demonstrated excellent biocompatibility and broad prospects in biomedicine application. Finally, the excellent selectivity of DECDs toward CTC was attributed to the FRET mechanism and the formation of complexes.

The critical role of the hippocampal NLRP3 inflammasome in social isolation-induced cognitive impairment in male mice.

Early life stress exerts detrimental effects on cognitive function, but the mechanism by which this occurs is unknown. The NLRP3 inflammasome-mediated inflammatory response has emerged as a prominent contributor to cognitive impairment induced by chronic stress. In the present study, we showed that 8-week chronic social isolation (SI) led to cognitive impairment in mice, remarkably increasing expression of the hippocampal NLRP3 inflammasome. Furthermore, the 8-week SI procedure significantly increased the levels of hippocampal IL-1ß and IL-18 without significant alteration of the level of serum IL-1ß, suggesting a central mechanism for IL-1ß-related CNS inflammation. Moreover, inflammatory microglial and expression of AMPAR were reduced in the hippocampus of SI mice. Minocycline is an antibiotic that limits microglia responses, and previous study also showed that minocycline could prevent stress-induced pro-inflammatory cytokine expression in the brain. Our experiment found that minocycline improved cognitive behavior in SI mice. Minocycline also prevented expression of the hippocampal NLRP3 inflammasome, indicating that microglia might be the primary contributor to SI-induced hippocampal NLRP3 inflammasome activation. Furthermore, alterations in SI mice were also restored by chronic treatment with the NLRP3 inhibitor MCC950. These results indicate that the microglia-derived NLRP3 inflammasome may be primarily involved in the inflammatory response to social isolation and that specific NLRP3 inflammasome inhibition using MCC950 may represent a promising therapeutic approach for early stress induced cognitive impairment.

Correction: Preparation of a colloidal photonic crystal containing CuO nanoparticles with tunable structural colors.

[This corrects the article DOI: 10.1039/C5RA21035F.].

[Differentiation of rat bone marrow mesenchymal stem cells into adipocytes and blockage of the differentiation].

OBJECTIVE: To explore the pathogenesis of tumors by blocking the normal differentiation process of stem cells. METHODS: Bone marrow mesenchymal stem cells (BMSCs) from rats were isolated, cultured and purified by whole bone marrow adherence method. The rat BMSCs were induced to differentiate into adipocytes with dexamethasone, insulin and indomethacin. Blockage of the differentiation process was induced by 3-methylcholanthrene (3-MC). RESULTS: The differentiation experiment showed that at 30 days after the induction, oil red O staining-positive cells occurred with increased intracytolasmic lipid droplets, characteristic for adipocytes. The differentiation blockage experiment showed that at 30 days after induction, the deposits of oil red O staining-cytoplasmic lipid droplets was significantly reduced, indicating that the blocked cells were adipocytes, but not fully differentiated. Morphological identification showed that cell contact inhibition disappeared, abnormal cell nuclei, increased number of micronucleus aberration and karyotype abnormalities, indicating that malignant transformation of the stem cells occurred after the differentiation blockage. CONCLUSIONS: The results of this study show a blockage of the differentiation of that stem cells at the intermediate phase, and a tendency of malignant transformation of the stem cells. The results of our study provide new evidence that cancer stem cells may be originated by suppression of stem cell differentiation.