Iron oxide-carbon core-shell nanoparticles for dual-modal imaging-guided photothermal therapy

Nanostructured materials that have low tissue toxicity, multi-modal imaging capability and high photothermal conversion efficiency have great potential to enable image-guided near infrared (NIR) photothermal therapy (PTT). Here, we report a bifunctional nanoparticle (BFNP,similar to 16 nm) comprised of a magnetic Fe3O4 core (similar to 9.1 nm) covered by a fluorescent carbon shell (similar to 3.4 nm) and prepared via a one-pot solvothermal synthesis method using ferrocene as the sole source. The BFNP exhibits excitation wavelength-tunable, upconverted and near-infrared (NIR) fluorescence property due to the presence of the carbon shell, and superparamagnetic behavior resulted from the Fe3O4 core. BFNPs demonstrate dual-modal imaging capacity both in vitro and in vivo with fluorescent imaging excited under a varying wavelength from 405 nm to 820 nm and with T-2-weighted magnetic resonance imaging (r(2) = 264.76 mM(-1) s(-1)). More significantly, BFNPs absorb and convert NIR light to heat enabling photothermal therapy as demonstrated mice bearing C6 glioblastoma. These BFNPs show promise as an advanced nanoplatform to provide imaging guided photothermal therapy.