(545a) Multi-Component Nanoparticles for Combined Fluorescence, Optical and Magnetic Resonance Imaging

Recent advances in synthesis strategies for the fabrication of nanoscale contrast agents has lead to significant advancements in the understanding of biological processes at the molecular level, the development of better diagnostic tools, and the ability to accurately monitor drug uptake for improved drug dosing. Nanocrystalline materials such as fluorescent-doped silica nanoparticles, quantum dots and paramagnetic nanomaterials have overcome many of the early limitations associated with conventional organic dye contrast agents, including poor photostability, low quantum yield and insufficient biological stability. However, challenges in the controlled and reproducible synthesis of biocompatible, bioinert nanomaterial contrast agents remain unmet.

In this work, we demonstrate the successful preparation hybrid nanoparticles for multi-modal imaging applications. Block copolymer nanoparticles successfully encapsulating organic fluorescent dyes, metal nanostructures and superparamagnetic materials are prepared for use in combined fluorescence, optical and magnetic resonance imaging applications. The nanoparticle preparation process, termed Flash NanoPrecipitation, relies on the controlled self assembly of incorporated agents and subsequent stabilization by a biocompatible amphiphilic block copolymer to yield highly stable nanoparticles with controlled size (50-300 nm), narrow particle size distributions, specific component composition, and high loading efficiencies. Because the process herein described relies solely on the control of mixing and aggregation timescales, and not on intrinsic physical properties of imaging components, it is anticipated that it can be expanded to include a wide variety of novel contrast agents, yielding nanoparticle formulations for integrated drug delivery and imaging applications.