Multimodality Imaging Probes: Design and Challenges

The design and challenges in multimodality imaging techniques are studied. One of the conceptually simplest approaches to generating multimodal contrast agents is to encapsulate more than one type of contrast agent into the aqueous phase of liposomes. Each approach relies on some method to disperse the lipid in a solution, typically after drying the lipids, so that the lipids may self-assemble into various forms of lipid spheres with aqueous centers. Tissue penetration can be achieved by modifying the lipid composition to one that allows uptake by cells or fusion to cell membranes and release of core contents. In addition to the use of synthetic lipids to form liposomal carriers, multimodal probes have been constructed by loading multiple types of probes to a naturally occurring lipoprotein vehicle, including low-density lipoprotein (LDL) 20 and high density lipoproteins (HDL). One of the most active areas of multimodality probe research has been in nanomaterials, which have proven to lend themselves well to the mixing required to generate multimodal functionality.