An international team of researchers has found a way to make iron oxide nanoparticles behave usefully for both MRI imaging and treatment of tumors: encase them inside larger silicon and polymer particles.
That creates versatile iron oxide composites that can act as MRI contrast agents, be manipulated with magnets, be heated, and degrade quickly. Normally, you would need different sizes of iron oxide particles to get those different functions.
The researchers made their “nanoconstructs” by embedding iron oxide particles in submicron-size silicon mesoporous particles (SiMPs) and discoidal polymeric nanoconstructs (DPNs). Previous research had shown that the SiMPs and DPNs naturally accumulate within a tumor’s blood vessels. The iron oxide allows them to be positioned more precisely using magnets, according to Ayrat Gizzatov, a graduate student at Rice University who is one of the researchers:
They get attracted by the magnet, and that induces another dipole-dipole magnetic interaction among the particles and increases their interparticle communication mechanism.
The researchers found the nanoconstructs to be excellent contrast agents. Confining the iron oxide in a geometric structure enhanced its relaxivity. And the particles can help fight disease as well as detect it. Once they’re in a tumor, they can be heated to destroy malignant tissue or trigger the release of tumor-fighting drugs.
The nanoconstructs should fully degrade and leave the body within a few days with no ill effects, the researchers found.
So far, the research subjects have been mice. We’ll keep an eye out for human trials.
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