Labeling of Polymer Nanostructures for Medical Imaging: Importance of Cross-Linking Extent, Spacer Length, and Charge Density

摘要

Nanoscale architectures, including spheres, cylinders, toroids, vesicles, disks, and other morphologies, have attracted much attention. Such nanoobjects with diverse properties have promise for many aspects of nanomedicine, for instance, as carriers to deliver therapeutic agents to specific targets with release of their payloads in a controlled fashion. Great efforts have been devoted to spherical micelles, which derive from amphiphilic block copolymers. Above the critical micelle concentration (cmc), micelles are thermodynamically stable in aqueous environments and are able to encapsulate hydrophobic drug molecules having poor water solubility. Meanwhile, their hydrophilic shell layer stabilizes the entire nanoobject and provides sites for addition of functional units. However, the stability of such nanoscale systems in vivo is of concern. To eliminate cmo restrictions, shell cross-linked nanoparticles (SCKs), a form of covalently stabilized micelles, have been developed by performing intramicellar cross-linking throughout the shell layer.