An iodinated liposomal computed tomographic contrast agent prepared from a diiodophosphatidylcholine lipid

Herein we report a novel vesicle-forming iodinated contrast agent for applications in computed tomographic (CT) imaging and drug delivery. Specifically, we have chemically modified a phosphatidylcholine lipid that is commonly used in liposome formation to create an iodinated lipid that self-assembles into similar to 50-150 nm iodoliposomes possessing as-prepared imaging contrast functionality. These iodoliposomes are structurally organized such that the iodinated moieties are contained within the vesicle's bilayer, leaving the liposomal interior unoccupied and thus available for encapsulating drugs. The iodoliposomes were characterized using electron microscopy and dynamic light scattering. We also calculated the iodoliposomes' iodine encapsulation efficiency, which was sufficient for use in current CT imaging protocols. These iodinated liposomes could also serve as multifunctional carriers upon the encapsulation of pharmaceutical agents, permitting simultaneous CT imaging and therapeutic treatment. Alternatively, the commercially available iodinated contrast agent iohexol could be encapsulated inside the iodoliposomes' aqueous core to further enchance their imaging contrast. (C) 2009 Elsevier Inc. All rights reserved.