Polymeric lipid assemblies as novel theranostic tools.

Polymerizable lipids have been used in research and medical applications such as membrane models, imaging platforms, drug delivery systems, vaccine carriers, biosensors, and coating materials. The polymerization of these lipid molecules forms a covalent bond between lipid moieties, which improves the noncovalent interactions that maintain the lipid lamellar phase architecture and increases the stability of the polymerized system. Because such lipid molecules form nanoassemblies with modifiable structures that acquire the stability of polymers following covalent bond formation, these lipids are of considerable interest in the emerging field of theranostics. In this Account, we summarize the biomedical applications of polymerizable lipids (primarily phospholipids) in the context of various nanoplatforms. We discuss stable nanoplatforms, which have been used in a variety of theranostics applications. In addition, we describe methods for assembling triggerable theranostics by combining appropriate nonpolymerizable lipids with polymerizable lipids. Polymeric lipids hold promise as nanotools in the field of medical imaging, targeting, and on-demand drug delivery. Because of their similarity to biological lipids, long-term toxicity issues from polymerizable lipid nanoplatforms are predicted to be minimal. Although the field of polymeric nanocapsules is still in development, intensive efforts are underway to produce systems which could be applied to disease diagnosis and treatment. We envision that nanoimaging platforms coupled with localized drug delivery technology will have a significant impact on cancer therapy and other related diseases. The existing wealth of clinical knowledge both in the photochemistry of imaging agents and/or drugs and modifications of these agents using light will prove valuable in the further development of polymeric theranostic lipid-based nanoparticles.