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 [¹⁷⁷Lu]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. Planar scintigraphy images demonstrated a moderate specific tumor uptake of melanoma-targeted [¹⁷⁷Lu]Lu-NPs10@D1_ICF_DOTAGA at 2 h post-intravenous injection (pi), and the highest tumor uptake of the control probe [¹⁷⁷Lu]Lu-NPs10@D1_DOTAGA at 30 min pi, probably due to the enhanced permeability and retention effect. In addition, ex vivo confocal microscopy studies showed a high specific targeting of human melanoma samples impregnated with NPs10@D1_ICF_Alexa647_ DOTAGA.

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

Superparamagnetic iron oxide nanoparticles synthesized by thermal decomposition have been grafted with two dendrons bearing respectively a monophosphonic anchor (D2) or a biphosphonic tweezer (D2-2P) at their focal point.

Validation of a dendron concept to tune colloidal stability, MRI relaxivity and bioelimination of functional nanoparticles

A dendritic coating induces colloidal stability of nanoparticles through electrostatic and steric interactions.

Cloned ovarian cells from sheep: Cholesterol dependency in progesterone synthesis

The TV4 cell line is derived from sheep ovarian tissues trypsinized for 60 min and developed from a clone after serial dilutions. The TV4 cells had a doubling time of 24 h in B2 medium with 10% fetal calf serum and 10% BSA. TV4 cells synthesized progesterone (P4) in the presence of cholesterol. As the concentration of cholesterol increased (0, 92.5 and 125 mg/l), synthesis of P4 increased (P<0.01) from 1.05 +/- 0.20 to 30.6 +/- 3.03 ng/ml. Kinetics of P4 production were determined; a linear production response (y = 5.816 + 1.05 x, y = ng/ml, x = hour of incubation; R(2) = 0.97) was observed with up to 35 ng/ml of P4 obtained by 30 h of incubation. Follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, or FSH and testosterone did not have any effect on estradiol-17beta (E2) or P4 production. Aromatase activity measured by RIA and HPLC following incubation with either nonradiolabeled or labeled testosterone was undetectable. In conclusion, this study established a cell line from the sheep ovary which has a high ability of divide and produce progesterone.