A Nano-sized PARACEST-fluorescence Imaging Contrast Agent Facilitates and Validates in vivo CEST MRI Detection of Glioma

Meser M Ali; Mohammed PI Bhuiyan; Branislava Janic; Nadimpalli RS Varma; Tom Mikkelsen; James R Ewing; Robert A Knight; Mark D Pagel; Ali S Arbab


Nanomedicine. 2012;7(12):1827-1837. 

In This Article

Future Perspective

This study demonstrates the merits of using a PAMAM dendrimer as a nanocarrier for imaging contrast agents. In the future, this approach can be exploited to improve the specificity for detecting glioma by using a nano-sized imaging contrast agent. This study also demonstrates the merits of dual-modality imaging contrast agents conjugated to a single dendrimer for cross-validation of results and for detecting pathological tissues at different spatial scales, which may be exploited in future studies as a short-term goal, and may be translated to the clinic as a long-term goal. Finally, this study demonstrated that in vivo CEST MRI is feasible with PARACEST agents conjugated to a dendrimer.

To relate this study to the authors' previous research, they used a common Eu(III) macrocyclic chelate. Future studies may employ other types of PARACEST agents that are responsive to tumor biomarkers such as tumor acidosis, protease enzyme activities or metabolites, which would provide additional diagnostic specificity for gliomas. Additionally, future studies may conjugate multiple types of PARACEST agents on a single dendrimer to detect multiple biomarkers of pathological tissues that will further improve diagnostic specificity. This study demonstrates the modular nature of conjugating PARACEST agents to a PAMAM dendrimer. Therefore, this study represents a milestone in the development of dual-modality, nano-sized contrast agents that can be detected with CEST MRI and optical imaging.