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Updated: Dec 24, 2025

Magnetic and Thermal-sensitive PolyN-isopropylacrylamide-based Microgels for Magnetically Triggered Controlled Release
Published on: July 4, 2017
Preparation and characterization of novel water-based biodegradable polyurethane nanoparticles encapsulating
1Institute of Polymer Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan, Republic of China. shhsu@ntu.edu.tw.
Abstract:
Superparamagnetic iron oxide nanoparticles (SPIO NPs) 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.

