Gold nanoparticles (AuNPs) are interesting for the design of new
cancer theranostic tools, mainly due to their biocompatibility, easy molecular vectorization, and good biological half-life. Herein, we report a
gold nanoparticle platform as a bimodal imaging probe, capable of coordinating Gd3+ for Magnetic Resonance Imaging (MRI) and 67Ga3+ for Single Photon Emission Computed Tomography (SPECT) imaging. Our AuNPs carry a
bombesin analogue with affinity towards the
gastrin releasing peptide receptor (GRPr), overexpressed in a variety of human
cancer cells, namely PC3
prostate cancer cells. The potential of these multimodal imaging nanoconstructs was thoroughly investigated by the assessment of their magnetic properties, in vitro cellular uptake, biodistribution, and radiosensitisation assays. The relaxometric properties predict a potential T1- and T2- MRI application. The promising in vitro cellular uptake of 67Ga/Gd-based
bombesin containing particles was confirmed through biodistribution studies in
tumor bearing mice, indicating their integrity and ability to target the GRPr. Radiosensitization studies revealed the therapeutic potential of the nanoparticles. Moreover, the
DOTA chelating unit moiety versatility gives a high
theranostic potential through the coordination of other therapeutically interesting radiometals. Altogether, our nanoparticles are interesting nanomaterial for
theranostic application and as bimodal T1- and T2- MRI / SPECT imaging probes.