Liposomes, micelles, and cross-linked hollow spheres have been the vessels of choice as nano-carriers for drug delivery applications. Recent advances in imprint lithography have merged the precision and uniformity associated with the microelectronics industry with organic chemistry to yield an engineering-based alternative for the fabrication of particles. The nanometer-sized agents described here are monodisperse having specific chemical functionality and possess tailored mechanical properties allowing for the precise control over particle size, shape, composition, cargo, modulus and surface properties making them ideal for applications in nano-medicine. We have demonstrated the effective use of PRINT (Particle Replication in Non-wetting Templates) to encapsulate contrast agents and be utilized as Magnetic Resonance Imaging (MRI) agents.

Cancer can be difficult to detect, and the earlier it is detected the chances of treating it effectively improve dramatically. Typical MRI contrast agents are comprised of paramagnetic chelates or super paramagnetic iron oxide (SPIO) nanoparticles (NPs). Chelates of Gd3+ are the most commonly used contrast agents in clinical MRI. We have successfully loaded PRINTTM particles with SPIO, as well as commercially available Gd contrast agents (OmniscanTM and ProhanceTM). Using these particles we have conducted phantom studies on both a 3T and 9.4T MRI in order to obtain relaxivity data. We have also studied in vivo contrast enhancement in healthy mice (C57BL/6J) with a solution of OmniscanTM loaded particles. We plan to use these particles in conjunction with targeting in order to image and track malignancies in vivo.