The design explores the conjugation strategy of simultaneously anchoring hyperbranched dendrimers, Fe3O4, and near infrared cyanine dye on oxidized graphene. Transmission electron microscopy (TEM) images reveal the nanosize and the conjugation of Fe3O4 nanoparticles on graphene nanosheets.

In the work, the group demonstrates the excellent dispersibility of the graphene nanosystem in aqueous media – an essential property of any new material intended for biological applications. Also the dendrimer–grapheme–Fe3O4 nanosystem responds to an external magnetic field, which may open up numerous applications.

Using confocal microscopy, the researchers evaluated the cellular internalization kinetics of the system with MCF-7 breast cancer cells. The nanosystem showed a longer residence time compared with free dye, which benefits cell imaging, and was observed in the cytoplasm and near perinuclear region.

Dual imaging capacity

The graphene nanosystem possesses dual imaging capacity thanks to the indocyanine fluorescent dye and by thermal imaging of Fe3O4. Furthermore, the cell viability study using MCF-7 cells indicated that the graphene multicomponent nanosystem was biocompatible even at a concentration of 100 µg ml–1.

Overall, the team concluded that the grapheme-based nanosystem has merits for cellular imaging and the delivery of bioactive agents.

A full description of the work can be found in the journal Nanotechnology.