Nicolas Drogat

Chlorin-PEI-labeled cellulose nanocrystals: synthesis, characterization and potential application in PDT.

This Letter reports the synthesis and characterization of a new series of water-stable and soluble photosensitizers (PS-CNCs) composed of cellulose nanocrystals (CNCs) bearing polyaminated chlorin p6. With a view to improve cancer cell targeting, these photosensitizers were assayed for their antitumor activity against HaCat cell line. IC(50) values fell within the nanomolar-range, making these photosensitizers promising for further in vitro and in vivo investigations.

Hydrophilic chlorin-conjugated magnetic nanoparticles—Potential anticancer agent for the treatment of melanoma by PDT

This Letter reports the synthesis and the characterization of two new water-stable and soluble photosensitizer-conjugated magnetic nanoparticles (PS-MNPs) composed of an iron oxide magnetic core coated with a biocompatible dextran shell bearing polyaminated chlorin p6. Designed to improve cancer cell targeting, these photosensitizers were assayed for their antitumour activity against two variants of B16 mouse melanoma cell line (B16F10 and B16G4F, with or without melanin, respectively). Cell viability measurements demonstrated that PS-MNPs were more phototoxic than PEI-chlorin p6 making these photosensitizers promising for further in vitro and in vivo investigations.

Optimization of the arsenazo-III method for the determination of uranium in water and plant samples

This work reports a reliable, fast and optimized photometric technique based on the specific chemical complexation of uranyl ion with arsenazo-III. In the case of solid samples (plant samples), for which mineralization under acidic and oxidative conditions was used, addition of ascorbic acid led to stabilization of the arsenazo-uranyl complex over time. The results, in total agreement with data obtained from α and γ spectrometries, demonstrate that the present technique is able to precisely quantify uranium in water as well as in plant samples, within the μg/L and mg/g ranges respectively.

One-Pot Silver Nanoring Synthesis

Silver colloidal nanorings have been synthesized by reducing silver ions with NaBH4 in trisodium citrate buffers. pH increase, by addition of NaOH, was used to speed up reduction reaction. The UV–vis absorption spectra of resulting silver nanorings showed two peaks accounting for transverse and longitudinal surface plasmon resonance, at ≈400 nm, and between 600 and 700 nm, respectively. The shapes of these silver nanoparticles (nanorings) depended on AgNO3/NaBH4 ratio, pH and reaction temperature. Particles were analysed by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. A reaction pathway is proposed to explain silver nanoring formation.