Magnetic-gold theranostic nanoagent used for targeting quad modalities T(1) & T(2)-MRI/CT/PA imaging and photothermal therapy of tumours

We describe a new type of ultra-small magneto-gold nanoparticle (MGN) with folic acid (FA)-based tumour targeting and multimodal imaging-guided photothermal therapy (PTT) properties that can be used as a theranostic nanoagent. The nanoagent integrates these MGNs–FA with surface modifications, and as expected, is monodisperse, and exhibits small size, strong NIR absorption, photothermal stability, good relaxivity and X-ray absorption coefficient, tumour targeting and excellent biocompatibility. Based on these properties, the nanoagent was successfully tested, both as a photothermal agent for high PTT efficacy and as a multimodality contrast agent for T(1)- & T(2)-MRI/CT/PA imaging in vitro and in vivo. Notably, the results of in vivo theranostic experiments with these MGNs–FA showed that they are highly effective and safe, indicating that they are efficient and promising theranostic agents that permit comprehensive imaging for diagnosis and therapy.