Abstract 5195: A novel, multimodal theranostic nanoprobe is effectively incorporated into melanoma brain metastatic cells

Abstract

Abstract Metastatic cancer is a significant cause of death worldwide, despite continuing advances in research on diagnostics and therapy. To overcome unsuccessful drug delivery to the tumor tissue, several different nanoprobes have been designed, of which some have combined diagnostic and therapeutic properties. It is an advantage to use non-toxic, biodegradable materials in the design of nanoprobes, as such compounds are easily eliminated from the body. In this work we report for the first time the use of a recently developed nanoprobe to label melanoma metastatic cell lines, for multimodal imaging of cellular uptake and drug delivery. Our nanoprobe consisted of a backbone of glycogen, where the red fluorescent marker Dyo-615 for fluorescence microscopy and Gadolinium for MRI were incorporated. Fluorescence microscopy showed effective labeling of human melanoma metastatic cells over 24 hours and cell viability was not affected by the labeling. The nanoprobe was found in the cytosol of the cells, and a gradual degradation of the probe inside the lysosomes could be observed. In vitro MRI relaxivity measurements showed significant reduction in T1 mapping times, compared to unlabeled cells. In vivo MRI studies showed that subcutaneous melanoma tumors in mice could be effectively visualized with T1 weighted MRI after intravenous injection of the nanoprobe, and the contrast enhancement was comparable to what was seen after using standard Omniscan contrast agent. In summary, our biodegradable glycogen nanoprobe shows a high potential to be used further as a theranostic entity. The nanoprobe may offer additional advantages over MRI contrast agents, as tumor uptake of pharmaceuticals attached to the nanoprobe can be traced in real-time in vivo. Citation Format: Synnøve N. Aasen, Tilo W. Eichler, Martin Hruby, Aneta Pospisilova, Petr Stepanek, Endy Spriet, Daniel Jirak, Kai Ove Skaftnesmo, Frits Thorsen. A novel, multimodal theranostic nanoprobe is effectively incorporated into melanoma brain metastatic cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5195. doi:10.1158/1538-7445.AM2015-5195