16 research outputs found
Novel synthesis of platinum complexes and their intracellular delivery to tumor cells by means of magnetic nanoparticles
Platinum-based drugs are popular in clinics as chemotherapeutic agents to treat solid tumors
Cerium Oxide Nanoparticle Administration to Skeletal Muscle Cells under Different Gravity and Radiation Conditions
For their remarkable biomimetic properties implying strong modulation of the intracellular and extracellular redox state, cerium oxide nanoparticles (also termed "nanoceria") were hypothesized to exert a protective role against oxidative stress associated with the harsh environmental conditions of spaceflight, characterized by microgravity and highly energetic radiations. Nanoparticles were supplied to proliferating C2C12 mouse skeletal muscle cells under different gravity and radiation levels. Biological responses were thus investigated at a transcriptional level by RNA next-generation sequencing. Lists of differentially expressed genes (DEGs) were generated and intersected by taking into consideration relevant comparisons, which led to the observation of prevailing effects of the space environment over those induced by nanoceria. In space, upregulation of transcription was slightly preponderant over downregulation, implying involvement of intracellular compartments, with the majority of DEGs consistently over- or under-expressed whenever present. Cosmic radiations regulated a higher number of DEGs than microgravity and seemed to promote increased cellular catabolism. By taking into consideration space physical stressors alone, microgravity and cosmic radiations appeared to have opposite effects at transcriptional levels despite partial sharing of molecular pathways. Interestingly, gene ontology denoted some enrichment in terms related to vision, when only effects of radiations were assessed. The transcriptional regulation of mitochondrial uncoupling protein 2 in space-relevant samples suggests perturbation of the intracellular redox homeostasis, and leaves open opportunities for antioxidant treatment for oxidative stress reduction in harsh environments
The one year fate of iron oxide coated gold nanoparticles in mice
Safe implementation of nanotechnology and nanomedicine requires an in-depth understanding of the life cycle of nanoparticles in the body. Here, we investigate the long-term fate of gold/iron oxide heterostructures after intravenous injection in mice. We show these heterostructures degrade in vivo and that the magnetic and optical properties change during the degradation process. These particles eventually eliminate from the body. The comparison of two different coating shells for heterostructures, amphiphilic polymer or polyethylene glycol, reveals the long lasting impact of initial surface properties on the nanocrystal degradability and on the kinetics of elimination of magnetic iron and gold from liver and spleen. Modulation of nanoparticles reactivity to the biological environment by the choice of materials and surface functionalization may provide new directions in the design of multifunctional nanomedicines with predictable fate
Maghemite Nanoparticles with Enhanced Magnetic Properties: One-Pot Preparation and Ultrastable Dextran Shell
International audienc
Cell-derived vesicles as a bioplatform for the encapsulation of theranostic nanomaterials
International audienceThere is a great deal of interest in the development of nanoplatforms gathering versatility and multifunctionality. The strategy reported herein meets these requirements and further integrates a cell-friendly shell in a bio-inspired approach. By taking advantage of a cell mechanism of biomolecule transport using vesicles, we engineered a hybrid biogenic nanoplatform able to encapsulate a set of nanoparticles regardless of their chemistry or shape. As a proof of versatility, different types of hybrid nanovesicles were produced: magnetic, magnetic-metallic and magnetic-fluorescent vesicles, either a single component or multiple components, combining the advantageous properties of each integrant nanoparticle. These nanoparticle-loaded vesicles can be manipulated, monitored by MRI and/or fluorescence imaging methods, while acting as efficient nano-heaters. The resulting assets for targeting, imaging and therapy converge for the outline of a new generation of nanosystems merging versatility and multifunctionality into a bio-camouflaged and bio-inspired approach
Maghemite Nanoparticles with Enhanced Magnetic Properties: One-Pot Preparation and Ultrastable Dextran Shell
In
the field of nanomedicine, superparamagnetic nanoparticles are
one of the most studied nanomaterials for theranostics. In this study,
a one-pot synthesis of magnetic nanoparticles is presented, with an
increased control on particle size from 10 to 40 nm. Monitoring of
vacuum level is introduced here as a crucial parameter for achieving
a fine particle morphology. The magnetic properties of these nanoparticles
are highly affected by disorders or mismatches in crystal structure.
A prolonged oxidation step is applied to the obtained nanoparticles
to transform the magnetic phases into a pure maghemite one, confirmed
by high-resolution X-ray photoelectron spectroscopy analysis, by Mössbauer
spectrometry and, indirectly, by increased performances in magnetization
curves and in relaxation times. Afterward, the attained nanoparticles
are transferred into water by a nonderivatized dextran coating. Thermogravimetric
analysis confirms that polysaccharide molecules replace oleic acid
on the surface by stabilizing the particles in the aqueous phase and
culture media. Preliminary in vitro test reveals that the dextran-coated
nanoparticles are not passively internalized from the cells. As a
proof of concept, a secondary layer of chitosan assures a positive
charge to the nanoparticle surface, thus enhancing cellular internalization
Co<sub><i>x</i></sub>Fe<sub>3–<i>x</i></sub>O<sub>4</sub> Nanocubes for Theranostic Applications: Effect of Cobalt Content and Particle Size
We report a facile synthesis of cube-shaped
Co<sub><i>x</i></sub>Fe<sub>3–<i>x</i></sub>O<sub>4</sub> nanocrystals
(NCs), which could be finely tuned in terms of NC size (from 15 to
27 nm) and cobalt stoichiometry (from 0.1 to 0.7). These particles
exhibited high specific absorption rate (SAR) values, relevant for
magnetic hyperthermia, and high relaxivity values, significant for
magnetic resonance imaging applications. The peculiarity of these
NCs is that already at low frequencies (such as 105 kHz, a working
frequency used on human patients), they display SAR values that are
three-times as large as those of iron oxide nanocubes of comparable
sizes (and which were already considered outstanding). The highest
SAR value recorded on the NCs reported here (915 ± 10 W/g<sub>(Co+Fe)</sub> at 105 kHz and 32 kAm<sup>–1</sup>) refers to
particles with cubic shape, 20 ± 2 nm edge size, and Co stoichiometry
between 0.6 and 0.7. The highest <i>r</i><sub>2</sub> value
(958 mM<sup>–1</sup> s<sup>–1</sup>) was instead recorded
on nanocubes with Co stoichiometry around 0.5/0.6 and size of 20 ±
2 nm. Remarkably, only at this specific size and Co stoichiometry
were the NCs not perfect cubes but had a slightly concave shape, which
together with their core–shell structure and magnetic parameters
might account for the higher <i>r</i><sub>2</sub> values
recorded. NCs reported here, with optimized SAR and <i>r</i><sub>2</sub> values, are promising tools for theranostic applications
One pot synthesis of monodisperse water soluble iron oxide nanocrystals with high values of the specific absorption rate
We report a highly reproducible route to synthesize iron oxide nanoparticles (IONPs) with control over size and shape and with size dispersions around 10%. By tuning the relative ratio of squalane to dibenzyl ether, which were used as solvents in the synthesis, the size of the particles could be varied from 14 to around 100 nm, while their shape evolved from cubic (for size ranges up to 35 nm) to truncated octahedra and octahedra (for sizes from 40 nm up to 100 nm). Fine tuning of the size within each of these ranges could be achieved by varying the heating ramp and the iron precursor to decanoic acid ratio. We also demonstrate direct water transfer of the as-synthesized IONPs via in situ ligand exchange with gallol polyethylene glycol molecules, the latter simply added to the crude nanocrystal mixture at 70 degrees C. The specific absorption rate (SAR) values measured on the water transferred IONPs, at frequencies and applied magnetic fields that are considered safe for patients, confirmed their high heating performance. Finally, this method allows the transfer of 35 nm nanocubes as individually coated and stable particles to the water phase. For the first time, the heating performance of such large IONPs has been studied. This work uncovers the possibility of using large IONPs for magnetic hyperthermia in tumor therapy