DDAO Controlled Synthesis of Organo-Modified Silica Nanoparticles with Encapsulated Fluorescent Boron Dipyrrins and Study of Their Uptake by Cancerous Cells.

The design of cargo carriers with high biocompatibility, unique morphological characteristics, and capability of strong bonding of fluorescent dye is highly important for the development of a platform for smart imaging and diagnostics. In this paper, BODIPY-doped silica nanoparticles were prepared through a "one-pot" soft-template method using a sol-gel process. Several sol-gel precursors have been used in sol-gel synthesis in the presence of soft-template to obtain the silica-based materials with the most appropriate morphological features for the immobilization of BODIPY molecules. Obtained silica particles have been shown to be non-cytotoxic and can be effectively internalized into the cervical cancer cell line (HeLa). The described method of synthesis allows us to obtain silica-based carriers with an immobilized fluorescent dye that provide the possibility for real-time imaging and detection of these carriers.

Highly luminescent Zn-Cu-In-S/ZnS core/gradient shell quantum dots prepared from indium sulfide by cation exchange for cell labeling and polymer composites.

Gradient core-shell Zn-Cu-In-S/ZnS quantum dots (QDs) of small size and with highly efficient photoluminescence were synthesized via a multi-step high-temperature method involving cation exchange. The procedure starts with the preparation of indium sulfide nanoparticles followed by the addition of Cu and Zn precursors. At this stage, Zn replaces Cu atoms and as a result the concentration of Cu ions in the final QDs is only about 5% of the total In content in a QD. Zn incorporation and the formation of a gradient ZnS shell dramatically increases the photoluminescence quantum yield. Furthermore, the formation of the ZnS shell improves the chemical stability of Cu-In-S QDs, as demonstrated by the preparation of polystyrene-QD composites and labeling of glioma cells. This work provides an effective strategy for obtaining efficient and stable fluorophores free of heavy metals.

Coordinative interaction between nitrogen oxides and iron-molybdenum POM Mo72Fe30.

The process of adsorption of nitrogen monoxide and dioxide by the giant Keplerate nanocluster Mo72Fe30 was studied in detail under ambient conditions and air/argon atmosphere. The obtained Raman and IR spectra showed that the coordination of NOx to the Mo72Fe30 leads to the formation of nitrate ions by sharing the bridged or terminal oxygen in FeO6 polyhedra with the adsorbed NO2 molecules. In accordance with elemental analysis and X-ray photoelectron spectroscopy, the composition of the produced complex was found to be [POM-(NO2)x]·(NO2)y (where x = 6, y = 14 ± 3). The carried out thermal analysis revealed the significant influence of NOx coordination in the release of water molecules and decomposition of the constitutional acetate ligands for Mo72Fe30. Furthermore, the performed measurements of the temperature dependency of the electron paramagnetic resonance spectra for the pure nanocluster and that treated with NO2 allowed us to draw up a conclusion about the delocalization of weak-bonded NO2 molecules in the pores of the Mo72Fe30 crystal at 25 °C. The opposite situation was observed under cryogenic temperatures. The localization of NO2 molecules occurs resulting in the distortion of FeO6 octahedra towards tetrahedral symmetry accompanied with the appearance of the signal at g-factor 4.3. The produced complex compound [POM-(NO2)x]·(NO2)y possesses sufficient NO2 capacity, water solubility and pH-dependant decomposition; these are important properties of a potential NOx donor, which can be hypothetically applied in biomedicine.