Preparation and characterization of novel water-based biodegradable polyurethane nanoparticles encapsulating superparamagnetic iron oxide and hydrophobic drugs

摘要

Superparamagnetic iron oxide nanoparticles (SPIO N Ps) are widely used in magnetic resonance imaging and magnetic hyperthermia. In this study, we used the self-assembly behavior of biodegradable polyurethane nanoparticles (PU NPs) in water to encapsulate SPIO NPs (SPIO-PU NPs) or hydrophobic model drugs (drug-PU NPs) by an in situ method. PU NPs and SPIO-PU NPs were characterized by dynamic light scattering, transmission electron microscopy, infrared spectroscopy, and thermogravimetric analysis. The superparamagnetic property and magnetic heating ability of SPIO-PU NPs were assessed. PU NPs had no significant cytotoxicity and could be taken up by cells. SPIO-PU NPs were highly efficient in labeling cancer cells with cellular uptake of ~16 pg iron per cell on average. Hydrophobic drugs were entrapped in PU NPs effectively and showed a sustained release profile. Upon heating, the release of drug was accelerated. This proof-of-concept study demonstrated a novel way to encapsulate SPIO and hydrophobic drugs in PU NPs with smart designs for potential applications in cancer diagnostics, hyperthermia, and chemotherapy.