Super-hydrophilic zwitterionic poly(carboxybetaine) and amphiphilic non-ionic poly(ethylene glycol) for stealth nanoparticles

This review compares two types of non-fouling polymers, the widely used nonionic poly(ethylene glycol) (PEG) and the recently established zwitterionic poly(carboxybetaine) (PCB), for their use in creating stealth nanoparticles (NPs) for drug delivery and protein protection. While both types of polymers exhibit reasonable non-fouling properties, such as good protein and colloidal stability and extended blood circulation time in vivo, amphiphilic PEG has negative effects on proteins and NPs due to its hydrophobic nature, including reduced protein bioactivity, instability of assembled NPs, and lipid bilayer destabilization. These problems can be overcome by super-hydrophilic PCB. (c) 2012 Elsevier Ltd. All rights reserved.