Dual Imaging Gold Nanoplatforms for Targeted Radiotheranostics

Abstract

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.

<p>Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy</p>

“…They have low permeability to normal capillaries and blood vessels in different tissues such as heart, lung, and skin; 8,11,16 5. As an imaging contrast agent, they can be used in disease diagnosis as well as biological imaging; 9,24,29,30 6. They have a well-controlled size distribution and GNPs have unique chemical, electrical, and optical properties in the range of 1-150 nm; 3,26,31 A number of unique GNP formats are currently undergoing preclinical development for various therapeutic and diagnostic applications -including radiotherapy, disease diagnosis, bioimaging (eg, computed tomography, photoacoustic imaging), therapeutic agent delivery (eg, drugs, genes, RNAs), biosensing and other therapies (eg, photothermal therapy, photodynamic therapy).…”

Radiolabeled Gold Nanoparticles for Imaging and Therapy of Cancer

“…The obtained biodistribution pattern is in perfect agreement with that observed for the same AuNPs without Gd. In addition, it was observed a very low uptake in the main organs and a high tumour retention (96.5 ± 26.0% and 76.8 ± 23.3% ID/g at 1 and 24 h after injection, respectively) following the intratumoural administration of the NPs [75].…”

Application of Nanomaterials in Biomedical Imaging and Cancer Therapy

“…The Au NPs had high affinity toward the gastrin-releasing peptide receptor. These receptors are overexpressed in various human cancer cells, mainly in PC3 prostate cancer cells [ 175 ]. A multifunctional targeting NP probe for pancreatic cancer was introduced that consists of 1,2 Distearoyl-sn-glycero-3-phosphoethanolamine-N-amino (polyethylene glycol)-modified SPIONs, which were conjugated with the plectin-1 antibody.…”