Gluco-Gold nanoparticles for metabolic based imaging
One of the main limitations of PET-CT, the highly used cancer imaging technique, is its inability to distinguish between cancerous lesions and post-treatment inflammatory conditions. The reason for this lack of specificity is that [18F]FDG-PET is based on increased glucose metabolic activity, which characterizes both cancerous tissues and inflammatory cells. In addition, it lacks anatomical information and thus necessitates incorporation of a structural imaging modality in order to obtain accurate anatomic information. The combination of PET with CT (PET/CT) enables both functional and anatomical information in a single setting. However, in view of the relatively high cost of PET scans, the dependence on the short-lived FDG and its non-specificity for cancer, the development of a single modality which will overcome these drawbacks is highly desirable. To answer this need, we developed a nanoparticle-based approach, utilizing glucose-functionalized gold nanoparticles (GF-GNPs) as a metabolically targeted contrast agent for computed tomography (CT) . This novel method demonstrates specific tumor targeting and has successfully distinguished between cancer and inflammatory processes in a combined tumor-inflammation mouse model, due to dissimilarities in angiogenesis occurring under different pathologic conditions. We further showed that despite the conjugation to the GNP, the glucose molecule preserves some of its activity, allowing glucose recognition and cellular internalization. Therefore, our approach provides simultaneous functional (metabolic) and structural imaging capabilities, with CT – the most widely available imaging modality. This study provides a set of capabilities in cancer detection, staging and follow-up, and can be applicable to a wide range of cancers that exhibit high metabolic activity.