Carbosilane Dendrimer 2G-NN16 Represses Tc17 Differentiation in Primary T CD8+ Lymphocytes

We studied changes in gene expression induced by the carbosilane dendrimer 2G-NN16 to evaluate their potential as a vehicle for gene therapy and as medication. Global gene expression profiles on CD8+ T lymphocytes reveal that ribosomal proteins are induced in the presence of 2G-NN16. IL17A and IL17F, the principal interleukins secreted by Tc17 cells, a subset of CD8+ T lymphocytes, were down-regulated when cultured in the presence of this dendrimer. Microarray results were confirmed by real time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). 2G-NN16 also showed a high potential for in vitro inhibition of Tc17 differentiation of CD8+ T lymphocytes in the presence of the Tc17 differentiation molecules IL6 and TGF-B1. These findings suggest that 2G-NN16 could facilitate drug delivery and may be used to treat inflammatory processes driven by Tc17 cells

Magnetic Interactions in the Double Perovskites R₂NiMnO₆ (R = Tb, Ho, Er, Tm) Investigated by Neutron Diffraction

R₂NiMnO₆ (R = Tb, Ho, Er, Tm) perovskites have been prepared by soft-chemistry techniques followed by high oxygen-pressure treatments; they have been investigated by X-ray diffraction, neutron powder diffraction (NPD), and magnetic measurements. In all cases the crystal structure is defined in the monoclinic <i>P</i>2₁/<i>n</i> space group, with an almost complete order between Ni²⁺ and Mn⁴⁺ cations in the octahedral perovskite sublattice. The low temperature NPD data and the macroscopic magnetic measurements indicate that all the compounds are ferrimagnetic, with a net magnetic moment different from zero and a distinct alignment of Ni and Mn spins depending on the nature of the rare-earth cation. The magnetic structures are different from the one previously reported for La₂NiMnO₆, with a ferromagnetic structure involving Mn⁴⁺ and Ni²⁺ moments. This spin alignment can be rationalized taking into account the Goodenough–Kanamori rules. The magnetic ordering temperature (<i>T</i>_CM) decreases abruptly as the size of the rare earth decreases, since <i>T</i>_CM is mainly influenced by the superexchange interaction between Ni²⁺ and Mn⁴⁺ (Ni²⁺–O–Mn⁴⁺ angle) and this angle decreases with the rare-earth size. The rare-earth magnetic moments participate in the magnetic structures immediately below <i>T</i>_CM

Improved Efficiency of Ibuprofen by Cationic Carbosilane Dendritic Conjugates

In order to improve the efficiency of the anti-inflammatory drug ibuprofen, cationic carbosilane dendrimers and dendrons with ibuprofen at their periphery or at their focal point, respectively, have been synthesized, and the release of the drug was studied using HPLC. Macrophages were used to evaluate the anti-inflammatory effect of the ibuprofen-conjugated dendritic systems and compared with mixtures of non-ibuprofen dendritic systems in the presence of the drug. The cationic ibuprofen-conjugated dendron was the compound that showed higher anti-inflammatory properties. It reduces the LPS-induced <i>COX-2</i> expression and decreases the release of several inflammatory cytokines such as TNFα, IL-1β, IL-6, and CCL3. These results open new perspectives in the use of these compounds as drug carriers

Magnetic Silica Nanoparticle Cellular Uptake and Cytotoxicity Regulated by Electrostatic Polyelectrolytes–DNA Loading at Their Surface

Magnetic silica nanoparticles show great promise for drug delivery. The major advantages correspond to their magnetic nature and ease of biofunctionalization, which favors their ability to interact with cells and tissues. We have prepared magnetic silica nanoparticles with DNA fragments attached on their previously polyelectrolyte-primed surface. The remarkable feature of these materials is the compromise between the positive charges of the polyelectrolytes and the negative charges of the DNA. This dual-agent formulation dramatically changes the overall cytotoxicity and chemical degradation of the nanoparticles, revealing the key role that surface functionalization plays in regulating the mechanisms involved