Evaluation of the Active Targeting of Melanin Granules after Intravenous Injection of Dendronized Nanoparticles.

The biodistribution of dendronized iron oxides, NPs10@D1_DOTAGA and melanin-targeting NPs10@D1_ICF_DOTAGA, was studied in vivo using magnetic resonance imaging (MRI) and planar scintigraphy through [Lu]Lu-radiolabeling. MRI experiments showed high contrast power of both dendronized nanoparticles (DPs) and hepatobiliary and urinary excretions. Little tumor uptake could be highlighted after intravenous injection probably as a consequence of the negatively charged DOTAGA-derivatized shell, which reduces the diffusion across the cells' membrane.

How a grafting anchor tailors the cellular uptake and in vivo fate of dendronized iron oxide nanoparticles.

Superparamagnetic spherical iron oxide nanoparticles of 10 nm diameter have been synthesized by thermal decomposition and grafted through a direct ligand exchange protocol with two dendrons bearing respectively a monophosphonic anchor (D2) or a biphosphonic tweezer (D2-2P) at their focal point. Physico-chemical characterization techniques such as dynamic light scattering (DLS), zeta potential, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and superconducting quantum interference device (SQUID) magnetometry were used to assess their composition, colloidal stability and magnetic properties. High-resolution magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy studies have been conducted to understand the organic shell composition and to determine both the grafting rate of the dendrons onto the nanoparticle surface and the influence of the remaining oleic acid originating from the synthesis protocol on the cellular uptake.

Preparation of core/shell NaYF:Yb,Tm@dendrons nanoparticles with enhanced upconversion luminescence for in vivo imaging.

Upconverting nanoparticles (UCNPs) were successfully dendronized for fluorescence medical imaging applications. The structural and morphological characterizations of resulting core/shell NaYF:Yb,Tm@dendrons nanoparticles were performed by means of X-ray diffraction, infrared spectroscopy and transmission electron microscopy. In vitro cytotoxicity assays have evidenced their low toxicity.

Dendrimer-nanoparticle conjugates in nanomedicine.

Nanomedicine can take advantage of the recent developments in nanobiotechnology research areas for the creation of platforms with superior drug carrier capabilities, selective responsiveness to the environment, unique contrast enhancement profiles and improved accumulation at the disease site. Colloidal inorganic nanoparticles (NPs) have been attracting considerable interest in biomedicine, from drug and gene delivery to imaging, sensing and diagnostics. It is essential to modify the NPs surface to have enhanced biocompatibility and reach multifunctional systems for the in vitro and in vivo applications, especially in delivering drugs locally and recognizing overexpressed biomolecules.

Radiolabeled dendritic probes as tools for high in vivo tumor targeting: application to melanoma.

In bioimaging, targeting allows refining the diagnosis by improving the sensitivity and especially the specificity for an earlier diagnosis. Two In-radiolabeled dendritic nanoprobes (DPs) (In-2, In-3) and their model counterparts (In-1, In-4) are designed and assessed for in vitro and in vivo tumor targeting efficiency in a murine melanoma models. Tumor uptake is correlated to dendrimer multivalency and reaches values as high as 12.