Jul 21, 2011
Fluorescent magnetic hybrid nanoprobes assembled for biomedical applications
In the past decade, we have witnessed an astonishing and multi-faceted transformation in the way we detect cancers and other diseases using imaging technology. Among these techniques, fluorescence and magnetic resonance imaging have contributed significantly in both basic research and clinical applications. Despite all of these achievements, no single imaging technique fulfills all of the needs considered to be ideal for imaging. To address this shortcoming, researchers in the US are focusing on combining fluorescent and magnetic imaging reporters to provide superior imaging properties through synergistic enhancements that are unmatched by any single modality.
The team, which includes scientists from Vanderbilt University, the Vanderbilt University Institute of Nanoscale Science and Engineering and the Vanderbilt University Institute of Imaging Science, has developed fluorescent magnetic hybrid nanoprobes for multimodal bioimaging.
Dual imaging channels
Stable colloidal dispersions of hybrid probes were formed by coupling semiconductor quantum dots to magnetic nanoparticles. The resulting imaging probes possess the attributes required for both magnetic resonance and fluorescent imaging in a single system.
Due to the unique optical properties of the quantum dots used in this fabrication, the emission of the nanoprobe could be tuned to the near-infrared range, a substantial benefit for in vivo imaging since the light-tissue interaction is minimal in this range.
Given the potential clinical applications of the particles, conventional cadmium containing quantum dots in the hybrid nanoprobe were replaced by cadmium-free quantum dots, thereby constituting a further welcome advance in the pursuit of biocompatible multimodal bioimaging.
To demonstrate the potential use of the newly developed imaging nanoprobes, the scientists used the particles to image lung lymph nodes in a mouse model system.
Thanks to its stability, the nanoprobe provides ideal characteristics for imaging targets that require longitudinal migration tracking. Aside from the cell tracking study, the researchers envision that the hybrid technology described in this work will provide an improved circulation half-life in vivo. This could potentially yield a longer residence time at the target site, thereby enhancing the contrast signal.
The team believes that this work will help in the development of new classes of multimodal imaging agents and contribute to improved medical diagnostic imaging and therapy.
Additional information can be found in the journal Nanotechnology.
About the author
The study was conducted by research teams at the Vanderbilt Institute of Nanoscale Science and Engineering and Vanderbilt Institute of Imaging Science in Nashville, Tennessee, US. The teams are part of a collaborative research unit supported by the National Institute of Biomedical Imaging and Bioengineering, which is focused on the development of multimodal agents for dendritic cells imaging (NIH R03EB009524). Prof. Dmitry Koktysh is working on development of semiconductor quantum dots and multimodal agents for imaging applications. Prof. Wellington Pham's research interests focus on the employment of novel molecular probes for investigation of the mechanisms that lead to pathological diseases. Vanessa Bright is pursuing a PhD under the direction of Prof. Pham.