The M de Jussieu's 'mirror of the Incas': an ecuadorian archaeological artefact in the mineralogical collection of René-Just Haüy (1743-1822).

This article reports on a historical investigation carried out on the conical object MIN000-3519 preserved in the mineralogy collections of the at Paris (France). The mineralogist René-Just Haüy (1743-1822) included this object, cut in a single pyrite (FeS) crystal, in his working collection with the references 'Sulphured iron, mirror of the Incas, of Peru, M. de Jussieu'.

Nanomagnetism reveals the intracellular clustering of iron oxide nanoparticles in the organism.

There are very few methods to investigate how nanoparticles (NPs) are taken up and processed by cells in the organism in the short and long terms. We propose a nanomagnetism approach, in combination with electron microscopy, to document the magnetic outcome of iron oxide-based P904 NPs injected intravenously into mice. The NP superparamagnetic properties are shown to be modified by cell internalization, due to magnetic interactions between NPs sequestered within intracellular organelles.

Long term in vivo biotransformation of iron oxide nanoparticles.

The long term outcome of nanoparticles in the organism is one of the most important concerns raised by the development of nanotechnology and nanomedicine. Little is known on the way taken by cells to process and degrade nanoparticles over time. In this context, iron oxide superparamagnetic nanoparticles benefit from a privileged status, because they show a very good tolerance profile, allowing their clinical use for MRI diagnosis.

Degradability of superparamagnetic nanoparticles in a model of intracellular environment: follow-up of magnetic, structural and chemical properties.

The unique magnetic properties of iron oxide nanoparticles have paved the way for various biomedical applications, such as magnetic resonance cellular imaging or magnetically induced therapeutic hyperthermia. Living cells interact with nanoparticles by internalizing them within intracellular acidic compartments. Although no acute toxicity of iron oxide nanoparticles has been reported up to now, the mechanisms of nanoparticle degradation by the cellular environment are still unknown.