Theranostics 2012; 2(12):1199-1207. doi:10.7150/thno.4812

Research Paper

Dual-Modality, Dual-Functional Nanoprobes for Cellular and Molecular Imaging

Jyothi U. Menon1, Praveen K. Gulaka2, Madalyn A. McKay1, Sairam Geethanath2, Li Liu1, Vikram D. Kodibagkar1,2,3,✉

1. Department of Radiology, UT Southwestern Medical Center at Dallas, Dallas, TX, USA;
2. Joint program in Biomedical engineering at UT Arlington and UT Southwestern Medical Center at Dallas, Dallas, TX, USA;
3. School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA.

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Menon JU, Gulaka PK, McKay MA, Geethanath S, Liu L, Kodibagkar VD. Dual-Modality, Dual-Functional Nanoprobes for Cellular and Molecular Imaging. Theranostics 2012; 2(12):1199-1207. doi:10.7150/thno.4812. Available from

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An emerging need for evaluation of promising cellular therapies is a non-invasive method to image the movement and health of cells following transplantation. However, the use of a single modality to serve this purpose may not be advantageous as it may convey inaccurate or insufficient information. Multi-modal imaging strategies are becoming more popular for in vivo cellular and molecular imaging because of their improved sensitivity, higher resolution and structural/functional visualization. This study aims at formulating Nile Red doped hexamethyldisiloxane (HMDSO) nanoemulsions as dual modality (Magnetic Resonance Imaging/Fluorescence), dual-functional (oximetry/detection) nanoprobes for cellular and molecular imaging. HMDSO nanoprobes were prepared using a HS15-lecithin combination as surfactant and showed an average radius of 71±39 nm by dynamic light scattering and in vitro particle stability in human plasma over 24 hrs. They were found to readily localize in the cytosol of MCF7-GFP cells within 18 minutes of incubation. As proof of principle, these nanoprobes were successfully used for fluorescence imaging and for measuring pO2 changes in cells by magnetic resonance imaging, in vitro, thus showing potential for in vivo applications.

Keywords: hexamethyldisiloxane, Nile Red, nanoemulsions, MR oximetry, fluorescence, dual-modality.