Self-assembled nanostructures are a class of nanomaterials having chemical and physical properties that are potentially beneficial for biomedical applications. Amphiphilic polymer micelle supramolecular structures, for example, have been proposed as a versatile nanomaterials platform for encapsulating, solubilizing, and facilitating delivery of poorly water soluble drugs, including chemotherapeutic agents. Incorporation of targeting ligands into amphiphilic polymer micelle supramolecular structures has promise to provide an effective route for targeted delivery of pharmaceuticals to specific cell types, tissues and organs. Use of micelle supramolecular structures for drug formulation and delivery applications is currently the subject of considerable research.
Polymer micelle supramolecular structures are typically formed via entropically driven self-assembly of amphiphilic polymers in a solution environment. For example, when block copolymers, having spatially segregated hydrophilic and hydrophobic domains are provided in aqueous solution at a concentration above critical micelle concentration (CMC) the polymers aggregate and self assemble such that hydrophobic domains form a central hydrophobic core and hydrophilic domains self assemble into an exterior hydrophilic corona region exposed to the aqueous phase. The core-corona structure of amphiphilic polymer micelles provides useful physical properties, as the hydrophobic core provides a shielded phase capable of solubilizing hydrophobic molecules, and the exterior corona region is at least partially solvated, thus imparting colloidal stability to these nanostructures.
A number of amphiphilic polymer systems, including block copolymers and cross linked block copolymer assemblies, have been specifically engineered and developed for biomedical applications, such as drug formulation and delivery applications. The following references provide examples of amphiphilic polymer drug delivery systems, including block copolymer drug delivery systems, which are hereby incorporated by reference in their entireties: (1) Li, Yali; Sun, Guorong; Xu, Jinqi; Wooley, Karen L., Shell Crosslinked Nanoparticles: a Progress Report on their Design for Drug Delivery; Nanotechnology in Therapeutics (2007), 381-407; (2) Qinggao Ma, Edward E. Remsen, Tomasz, Kowalewski, Jacob Schaefer, Karen Wooley, “Environmentally-responsive, Entirely, Hydrophilic, Shell Cross-linked (SCK) Nanoparticles” Nano Lett. 2001, 1, 651; (3) Jones, M.-C.; Leroux J.-C. “Polymeric Micelles: A New Generation of Colloidal Drug Carriers” Eur. J. Pharm. Biopharm. 1999, 48, 101-111; and (4) Kwon, G. S.; Naito, M.; Kataoka, K.; Yokoyama, M.; Sakurai, Y.; Okano, T. “Block Copolymer Micelles as Vehicles for Hydrophobic Drugs” Colloids and Surfaces, B: Biointerfaces 1994, 2, 429-34.
Although polymer systems have been suggested for drug delivery systems, the use of polymer supramolecular assemblies for tandem optical imaging and therapy has not been provided. The ability to use one molecular system for drug delivery and imaging is provided in this invention.