(537c) Multifunctional, Biodegradable, Magnetic Nanoparticles Based On Zwitterionic Polymers

Stealth, functionalizable and biodegradable magnetic nanoparticles (MNPs) based on zwitterionic polymer were developed by a convenient one-step method. Water soluble monodisperse iron oxide nanoparticles were encapsulated by crosslinking poly(carboxybetaine methacrylate) (pCBMA) with a degradable linkage. The pCBMA-MNPs had superparamagnetic properties and a hydrodynamic particle size of about 100nm. Without any further modification, the pCBMA-MNPs could achieve long term stability in phosphate-buffered saline (PBS) and complex medium like 100% human blood serum at 37oC. In vitro test showed the ultra-low uptake of pCBMA-MNPs by macrophage cells and their potentially stealth properties. Moreover, the pCBMA coating could also be functionalized by targeting ligand which dramatically enhanced their cell uptake efficiency. The polymer coating could be degraded in the intracellular environment, rendering the efficient release of the encapsulated drug from the pCBMA-MNPs. The above properties made the pCBMA-MNPs an ideal platform for image-guided targeting drug delivery.