Biocompatible magnetic nanoparticles for diagnose and treatment.

A Spanish public research organisation has developed a method to obtain magnetic nanoparticles with size between 5-30 nm made of a magnetite core covered by a bismuth shell. The nanoparticles, of high cristalinity and low size dispersion, can be employed for diagnose by RMN, MRI or TAC, as tumor markers or for therapeutic applications (drug carrier or heat source for treatment by magnetic hyperthermia). Partners interested in a patent license are being sought.

Magnetic nanoparticles have proven its use as cell magnetic separators, transport of antitumor molecules, for hyperthermal treatment and as contrast agent for nuclear magnetic resonance (NMR), among other biomedical applications. Researchers have found the properties of magnetic nanoparticles made of magnetite, a biocompatible material with particle size appropriate for injection in patients, to be improved by adding bismuth, an element with well-known bioutility. Nanoparticles containing bismuth can be used as substitute for iodated compounds in X-ray computer tomography (CT).
A Spanish research group has developed new hybrid nanoparticles with a magnetite nucleus and a bismuth coating, named Bi-magnetite, with better biomedical properties than products already avaliable in the market. The presence of bismuth on their surface and the particle size (5-30 nm) confer Bi-magnetite a high opacity against X-rays, both with CT and NMR. The value of the saturation field (35-80 emu/g), close to bulk magnetite, is a consecuence of a high cristallinity.
Bi-magnetite can transport active principles, antibiotics or anticancer molecules, thanks to a high magnetic moment and its colloidal properties. Moderate toxicity enables its use in patients for diagnose or treatment of tumours. Bismuth enhances functionalization of both nanoparticles and active principles. Detection of tumours is achieved by comparison of tissues: nanoparticles are captured by healthy cells, but not by those damaged by cancer.
The anti-cancer activity of nanoparticles is enhanced at high temperature, caused e.g. by a time-dependent magnetic field. It is also possible to use Bi-magnetite as heat source to generate a localized temperature raise (magnetic hyperthermia). A combination of an anti-cancer active principle with Bi-magnetite nanoparticles can therefore boost tumour cell elimination.
Nanoparticles are obtained from a solution in water and alcohol of an acid, a salt that contains iron and a bismuth salt. When mixed with an alkaline solution in water and ethanol, a precipitate is formed which, under proper environmental conditions, leads to nanoparticles of homogen size.

" The preparation procedure uses cheap inorganic precursors, non-toxic and easily accesible, in addition to hydro-alcoholic solutions (i.e. not exclusively aequous or alcoholic) in presence of bismuth.
" Particles form with a monodisperse distribution (i.e. a size dispersion below 20% from average size).
" Tumours can be detected in their initial stages, even when their size lies below 2 mm.
" The reaction in which Bi-magnetite particles are formed has a high output and requires only modeate temperatures (below 100 ºC) to grow under control.
" Images with better quality and resolution are obtained by the combination of NMR and CT techniques with the same contrast agent, a feature not available when using them separately.
" The size of the nanoparticles can be controlled by changing the Bi/Fe ratio.
" The particles may be used in both in vivo or in vitro applications.

Source: Enterprise Europe Network – consortium Sud-Ouest France (12 ES 28G2 3NVY)

Opportunities

• Technology transfer
• Seeking technical partners

Scientific typology

- Type of partner sought: industrial - Specific area of activity of the partner: manufacturers of markers for X-rays, NMR or MRI; manufacturers of nanoparticles or magnetic materials - Task to be performed by the partner sought: commercial development and commercialization

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