Introduction de la technique du ganglion sentinelle dans les cancers de cavité orale au CHU de Besançon (apport de la TEMP-TDM)

BESANCON-BU Médecine pharmacie (250562102) / SudocSudocFranceF

Fission fragment track etching modelling for the cellular localisation of Neptunium-237 nuclei in rat tissues

International audienceHeavy ion recording in dielectric isotropic detectors has a wide range of applications in uranium cartography or dating. In this study, solid state nuclear tracks detectors (SSNTDs) have been applied to localise neptunium-237, in vivo, by means of the neutron-induced fission cartography of neptunium-237 nuclei in organ sections. At the cellular level, a precise localisation can only be achieved with a good understanding of the etch pit evolution during the chemical etching process. A tailor-made software for modelling the etching process has been developed to simulate the profile of an etched track produced by a neutron-induced fission fragment. This software is based on a model that considers the evolution of the track etching velocity along the damage trail in order to perfectly model the shape of the track

Theoretical study of the interaction between carbon nanotubes and carboplatin anticancer molecules

International audienceFull DFT calculations were carried out to study the interactions between single-wall functionalized carbon-based metallic nanotubes (CNTs) and carboplatin anticancer drugs. The geometry of the CNT-carboplatin was optimized considering different molecular configurations on inner and outer surfaces of the nanotubes. Simulation results show that the most stable physisorption state for molecules is to be located inside the nanotubes in a parallel configuration. Furthermore{,} we demonstrated that the molecular physisorption was reinforced as soon as the number of encapsulated carboplatin molecules increased{,} leading to a favored state where the nanovector is filled by the drug. Moreover{,} all theoretical results show that the therapeutic agent is not affected when it is attached onto CNT

Theoretical Demonstration of the Potentiality of Boron Nitride Nanotubes to Encapsulate Anticancer Molecule

International audienceAnticancer drug transport is now becoming an important scientific challenge since it would allow localizing the drug release near the tumor cell, avoiding secondary medical effects. We present theoretical results, based on density functional theory and molecular dynamics simulations, which demonstrate the stability of functionalized single (10,10) boron nitride nanotubes (BNNTs) filled with anticancer molecule such as carboplatin (CPT). For this functionalized system we determine the dependence of the adsorption energy on the molecule displacement near the inner BNNTs surface, together with their local morphological and electrical changes and compare the values to the adsorption energy obtained on the outer surface. Quantum simulations show that the most stable physisorption state is located inside the nanotube, with no net charge transfer. This demonstrates that chemotherapeutic encapsulation is the most favorable way to transport drug molecules. The solvent effect and dispersion repulsion contributions are then taken into account using molecular dynamics simulations. Our results confirm that carboplatin therapeutic agents are not affected when they are adsorbed inside BNNTs by the surrounding water molecules

Theoretical use of boron nitride nanotubes as a perfect container for anticancer molecules

International audienceIn recent years great interest has emerged in the development of nanocarriers for drug transport. One of themajor challenges is to obtain a drug delivery system able to control the drug release profile, transportabsorption and distribution, in the view of improving efficacy and safety. Herein, we present theoreticalresults based on density functional theory (DFT) to determine the best adsorption site for the anticancerifosfamide molecule in boron nitride nanotubes. For this functionalized system we determine thedependence of the adsorption energy on the displacement of molecules in the outer and inner boronnitride surfaces, together with their local morphological and charge modifications. Quantum simulationsshow that the most stable physisorption state is located inside the nanotube, with no net charge transferbetween each subsystem, and no barrier energy at the nanotube entrance. This demonstrates thatchemotherapeutic encapsulation is the most favorable way for ifosfamide to be vectorized

Encapsulation capacity and natural payload delivery of an anticancer drug from boron nitride nanotube

International audienceThe behavior of confined anticancer carboplatin (CPT) molecules in a single (10, 10) boron nitridenanotube (BNNT) was studied by means of molecular dynamics simulations. Our study revealed a verylarge storage capacity of BNNT. Analysis of the energy profiles depending on the number of confinedmolecules, and on their spatial organization allowed us to quantify the ability of BNNT to vectorize CPT.Indeed, BNNT despite its small radius presented a large inner volume that favored stable encapsulationof multiple active anticancer molecules. Moreover, in our molecular dynamics simulations, the emptyBNNT and the BNNT filled with CPT diffused spontaneously to the cell membrane and were able topassively enter inside lipid bilayers by a lipid-assisted mechanism. This property has been used to delivernaturally anticancer drugs to cellular targets. Using this enhanced drug delivery system, we haveprovided a definitive solution to the problem of drug release and have thus opened up a new way oftargeting cancer cells. Indeed, regardless of the mode of action of the platinum complex towards thecell, the delivery of the drug on site should limit the side effects of the drug

FDG Brain PET/CT Revealing Bilateral Thalamostriatal Activation During a Symptomatic Episode in a Patient With Kleine-Levin Syndrome

International audienceWe report the case of a 14-year-old girl with clinically diagnosed Kleine-Levin syndrome. Electroencephalogram and brain MRI were unremarkable. An FDG PET/CT scan was acquired during a symptomatic episode, while she was asleep, and another PET scan was obtained when she was asymptomatic, awake, and quiet. Comparison of both examinations demonstrated a bilateral activation of thalami, caudate nuclei, and lenticular nuclei. These findings may be linked to the implication of thalamostriatal structures in the regulation of sleep and wakefulness

Unusual uptakes on 18F-fluorocholine positron emission tomography/computed tomography (PET/CT): a retrospective study of 368 prostate cancer patients referred for a biochemical recurrence or an initial staging

International audienc

Lipid nanocapsules functionalized with polyethyleneimine for plasmid DNA and drug co-delivery and cell imaging

The paper reports on the preparation of lipid nanocapsules (LNCs) functionalized with poly(ethyleneimine) (PEI) moieties and their successful use as drug and gene delivery systems. The cationic LNCs were produced by a phase inversion process with a nominal size of 25 nm and subsequently modified with PEI chains using a transacylation reaction. The functionalization process allowed good control over the nanoscale particle size (26.2 ± 3.9 nm) with monodisperse size characteristics (PI < 0.2) and positive surface charge up to +18.7 mV. The PEI-modified LNCs (LNC25-T) displayed good buffering capacity. Moreover, the cationic LNC25-T were able to condense DNA and form complexes via electrostatic interactions in a typical weight ratio-dependent relationship. It was found that the mean diameter of LNC25-T/pDNA complexes increased to ∼40-50 nm with the LNC25-T/pDNA ratio from 1 to 500. Gel electrophoresis and cell viability experiments showed that the LNC25-T/pDNA complexes had high stability with no cytotoxicity due to the anchored PEI polymers on the surface of LNCs. Finally, the transfection efficiency of the LNC25-T/pDNA complexes was studied and evaluated on HEK cell lines in comparison with free PEI/pDNA polyplexes. The combination of cationic LNCs with pDNA exhibited more than a 2.8-fold increase in transfection efficiency compared to the standard free PEI/pDNA polyplexes at the same PEI concentrations. Moreover, we have demonstrated that LNC25-T/pDNA loaded with a hydrophobic drug, paclitaxel, showed high drug efficacy. The high transfection efficiency combined with the potential of simultaneous co-delivery of hydrophobic drugs, relatively small size of LNC25-T/pDNA complexes, and fluorescence imaging can be crucial for gene therapy, as small particle sizes may be more favorable for in vivo studies