Modular Self‐Assembling Dendrimer Nanosystems for Magnetic Resonance And Multimodality Imaging of Tumors

Bioimaging is a powerful tool for diagnosing tumors but remains limited in terms of sensitivity and specificity. Nanotechnology‐based imaging probes able to accommodate abundant imaging units with different imaging modalities are particularly promising for overcoming these limitations. In addition, the nanosized imaging agents can specifically increase the contrast of tumors by exploiting the enhanced permeability and retention effect. We performed a proof‐of‐concept study on pancreatic cancer to demonstrate the use of modular amphiphilic dendrimer‐based nanoprobes for magnetic resonance imaging (MRI) or MR/near‐infrared fluorescence (NIRF) multimodality imaging of tumors. Specifically, self‐assembly of an amphiphilic dendrimer bearing multiple Gd 3+ contrast units at its terminals, generated a nanomicellar agent exhibiting favorable relaxivity for MRI with a good safety profile. MRI revealed an up to 2‐fold higher contrast enhancement in tumors than in normal muscle. Encapsulating the NIRF dye within the core of the nanoprobe yielded an MR/NIRF bimodal imaging agent for tumor detection that was efficient both for MRI, at Gd 3+ concentrations 1/10 the standard clinical dose, and for NIRF imaging, allowing over two‐fold stronger fluorescence intensities. These self‐assembling dendrimer nanosystems thus constitute effective probes for MRI and MR/NIRF multimodality imaging, and offer a promising nanotechnology platform for elaborating multimodality imaging probes in biomedical applications. This article is protected by copyright. All rights reserve