Self-Assembled Stimuli-Responsive Polyrotaxane Core–Shell\nParticles

Abstract

Thermodynamically\nassembled core–shell nanocarriers are\npotential candidates for drug delivery applications due to their submicrometer\nsize and the ability to load drugs into their hydrophobic core. Herein,\nwe describe the formation of core–shell particles that consist\nof noncovalent polymers, that is, polyrotaxanes (PRXs), that form\nan α-cyclodextrin (αCD) core surrounded by a corona of\nlow-fouling poly­(ethylene glycol) (PEG). The PRX core–shell\nparticles are able to sequester small organic molecules, such as pyrene\nand calcein, releasing these small molecules during degradation. The\nsmall, cellular peptide, glutathione, was used to degrade the particles\nthrough the reductive cleavage of disulfide bonds that stabilize the\nindividual PRX polymers. Cleavage of a single bond allows for the\ndegradation of the supramolecular-polymer, making these PRX core–shell\nparticles highly responsive. Furthermore, these particles demonstrate\nnegligible cytotoxicity in mammalian cells, making them promising\ncarriers for future drug delivery research.