The simple preparation of polyethylene glycol-based soft nanoparticles containing dual imaging probes.

We developed a simple method to prepare PEG-based soft nanoparticles that encapsulate dual imaging probes. Because the probes could be encapsulated by either chemical or physical means, a variety of probe molecules were encapsulated within the nanoparticles simultaneously. The nanoparticles were administrated to mice and the pharmacokinetics of the nanoparticles was analyzed by means of MRI, fluorescence spectroscopy, and transmission electron microscopy.