Core-Shell Pluronic-Organosilica Nanoparticles with Controlled Polarity and Oxygen Permeability.

Nanostructured systems constitute versatile carriers with multiple functions engineered in a nanometric space. Yet, such multimodality often requires adapting the chemistry of the nanostructure to the properties of the hosted functional molecules. Here, we show the preparation of core-shell Pluronic-organosilica "PluOS" nanoparticles with the use of a library of organosilane precursors.

Tandem Dye-Doped Nanoparticles for NIR Imaging via Cerenkov Resonance Energy Transfer.

The detection of the Cerenkov radiation (CR) is an emerging preclinical imaging technique which allows monitoring the distribution of radionuclides. Among its possible advantages, the most interesting is the simplicity and cost of the required instrumentation compared, e.g.

Mapping heterogeneous polarity in multicompartment nanoparticles.

Understanding polarity gradients inside nanomaterials is essential to capture their potential as nanoreactors, catalysts or in drug delivery applications. We propose here a method to obtain detailed, quantitative information on heterogeneous polarity in multicompartment nanostructures. The method is based on a 2-steps procedure, (i) deconvolution of complex emission spectra of two solvatochromic probes followed by (ii) spectrally resolved analysis of FRET between the same solvatochromic dyes.

Synthesis of Film-Forming Photoactive Latex Particles by Emulsion Polymerization-Induced Self-Assembly to Produce Singlet Oxygen.

The design of photoactive polymer substrates producing singlet oxygen under visible light irradiation has great technological potential. Aqueous dispersion of novel photoactive core-shell particles was synthesized by surfactant-free reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization of n-butyl acrylate. The surface of the nanoparticles is directly decorated thanks to the polymerization-induced self-assembly process using a hydrophilic macromolecular chain transfer agent (macro-CTA) functionalized with the organic photosensitizer.

Cubosomes for in vivo fluorescence lifetime imaging.

Herein we provided the first proof of principle for in vivo fluorescence optical imaging application using monoolein-based cubosomes in a healthy mouse animal model. This formulation, administered at a non-cytotoxic concentration, was capable of providing both exogenous contrast for NIR fluorescence imaging with very high efficiency and chemospecific information upon lifetime analysis. Time-resolved measurements of fluorescence after the intravenous injection of cubosomes revealed that the dye rapidly accumulated mainly in the liver, while lifetimes profiles obtained in vivo allowed for discriminating between free dye or dye embedded within the cubosome nanostructure after injection.

Variable Doping Induces Mechanism Swapping in Electrogenerated Chemiluminescence of Ru(bpy) Core-Shell Silica Nanoparticles.

The impact of nanotechnology on analytical science is hardly overlooked. In the search for ever-increasing sensitivity in biomedical sensors, nanoparticles have been playing a unique role as, for instance, ultrabright labels, and unravelling the intimate mechanisms which govern their functioning is mandatory for the design of ultrasentitive devices. Herein, we investigated the mechanism of electrogenerated chemiluminescence (ECL) in a family of core-shell silica-PEG nanoparticles (DDSNs), variously doped with a Ru(bpy) triethoxysilane derivative, and displaying homogeneous morphological, hydrodynamic, and photophysical properties.

Multimodal near-infrared-emitting PluS Silica nanoparticles with fluorescent, photoacoustic, and photothermal capabilities.

Purpose: The aim of the present study was to develop nanoprobes with theranostic features, including - at the same time - photoacoustic, near-infrared (NIR) optical imaging, and photothermal properties, in a versatile and stable core-shell silica-polyethylene glycol (PEG) nanoparticle architecture.

Materials And Methods: We synthesized core-shell silica-PEG nanoparticles by a one-pot direct micelles approach. Fluorescence emission and photoacoustic and photothermal properties were obtained at the same time by appropriate doping with triethoxysilane-derivatized cyanine 5.

Luminescent Silica Nanoparticles Featuring Collective Processes for Optical Imaging.

The field of nanoparticles has successfully merged with imaging to optimize contrast agents for many detection techniques. This combination has yielded highly positive results, especially in optical and magnetic imaging, leading to diagnostic methods that are now close to clinical use. Biological sciences have been taking advantage of luminescent labels for many years and the development of luminescent nanoprobes has helped definitively in making the crucial step forward in in vivo applications.

Reversal of the glycolytic phenotype of primary effusion lymphoma cells by combined targeting of cellular metabolism and PI3K/Akt/ mTOR signaling.

PEL is a B-cell non-Hodgkin lymphoma, occurring predominantly as a lymphomatous effusion in body cavities, characterized by aggressive clinical course, with no standard therapy. Based on previous reports that PEL cells display a Warburg phenotype, we hypothesized that the highly hypoxic environment in which they grow in vivo makes them more reliant on glycolysis, and more vulnerable to drugs targeting this pathway. We established here that indeed PEL cells in hypoxia are more sensitive to glycolysis inhibition.

Further optimization of plakortin pharmacophore: structurally simple 4-oxymethyl-1,2-dioxanes with promising antimalarial activity.

For the optimization of the plakortin pharmacophore, we recently proposed a straightforward synthesis of 4-carbomethoxy-3-methoxy-1,2-dioxanes as potential antimalarial drug candidates. Herein we report the chemoselective reduction of the 4-carbomethoxy group which has allowed us to prepare in good yields twenty-four new endoperoxides carrying either the hydroxymethyl or the methoxymethyl group on C4 in various stereochemical arrangements with respect to the alkyl groups on C3 and C6 (the endoperoxide carbons). Some of these compounds showed promising in vitro antimalarial activities, both against chloroquine-resistant (CQ-R) and susceptible (CQ-S) strains of Plasmodium falciparum, with IC₅₀ values in the range of 0.

Proper design of silica nanoparticles combines high brightness, lack of cytotoxicity and efficient cell endocytosis.

Silica-based luminescent nanoparticles (SiNPs) show promising prospects in nanomedicine in light of their chemical properties and versatility. In this study, we have characterized silica core-PEG shell SiNPs derivatized with PEG moieties (NP-PEG), with external amino- (NP-PEG-amino) or carboxy-groups (NP-PEG-carbo), both in cell cultures as well as in animal models. By using different techniques, we could demonstrate that these SiNPs were safe and did not exhibit appreciable cytotoxicity in different relevant cell models, of normal or cancer cell types, growing either in suspension (JVM-2 leukemic cell line and primary normal peripheral blood mononuclear cells) or in adherence (human hepatocarcinoma Huh7 and umbilical vein endothelial cells).