In their latest study, the team has prepared and characterized monodisperse nanometric magnetite cores covered by a layer of gold and protected by a corona of organic molecules. The utility of electron magnetic resonance spectroscopy (EMR) is demonstrated in confirming the enhancement of the superparamagnetic behaviour due to the gold layer and the organic corona.

Anchor points

Appropriate modification of the surface of the particles by incorporating carboxyl groups as anchor points enabled further functionalization. In turn, this allowed the scientists to tailor surface compositions, overcoming biocompatibility issues and providing a versatile platform to evaluate nanoparticle–cell interactions.

Molecules relevant for bioapplications, such as poly(ethylene glycol) (PEG) and glucose, were covalently conjugated to the particle surface via amidation reactions, and a dye was also grafted to monitor cell response upon incubation with the developed particles. Using confocal microscopy it was discovered that glucose-coated particles showed increased penetration across the cell membrane of HeLa cells (see image) in comparison with PEG-coated particles. These results suggest that glucose could be used to tailor a nanoparticle shield in applications that require high cellular uptake.

The group is currently developing new magnetic nanomaterials with various morphologies, compositions and biofunctionalities. This is with two aims in mind; to evaluate the heat generated by the nanoparticles in terms of the specific absorption rate (SAR) and to assess the endocytic mechanism of particles upon incubation with different cell lines.

Additional information can be found in the journal Nanotechnology.