Folic acid (FA) is widely used in tumor targeting due to its non-immunogenicity and high specificity with Fe3O4 nanoparticles being extensively applied in magnetic resonance imaging (MRI). Hollow gold nanospheres meanwhile have strong and tunable localized surface plasmon resonance (LSPR) properties with excellent photothermal conversion. These desirable properties make them ideal for use in photoacoustic imaging (PAI) and photothermal therapy (PTT) of cancer cells. HGNs functionalized with FA and Fe3O4 nanoparticles therefore have great potential in targeted cancer cell imaging, diagnosis and therapy.

HGNs@Fe3O4-FA probe

The researchers design a novel HGNs@Fe3O4-FA probe for application in in bimodal cancer cell imaging and photothermal therapy. The probe is based on magnetic gold nanocomposites with HGNs as cores and ultrasmall Fe3O4 nanoparticles (NPs) as satellites. The Fe3O4 nanoparticles are covalently attached to the surface of HGNs by Au-S bonds and folic acid is conjugated through a cross-linker. They find that the probe not only has great MRI/PAI performance but also exhibits good photothermal effect under the irradiation of near-infrared laser.

Cancer diagnosis and therapy

The HGNs@Fe3O4-FA probe shows significant contrast enhancement for T2-weighted MRI and strong PAI signal enhancement. It also demonstrates good photothermal conversion under irradiation by a near-infrared laser. Such nanocomposites with combined MRI-PAI and PTT functionality are therefore great potential candidates for effective cancer diagnosis and therapy applications.

Applications

From these investigations, it is evident that these nanocomposites are great potential candidates for many biological applications such as drug delivery, gene transfection, and bio-imaging.

More information about this research can be found in the journal Nanotechnology 26 315701.

Further reading

Fluorescent-magnetic nanobeads: detecting rare cancer cells (Dec 2014)
Magnetic particle hyperthermia: a promising tumour therapy? (Nov 2013)
Targeting melanoma with peptide-conjugated nanoparticles (Jul 2015)