Stable polymersomes based on ionic-zwitterionic block copolymers modified with superparamagnetic iron oxide nanoparticles for biomedical applicationsElectronic supplementary information (ESI) available. See DOI: 10.1039/c5tb00182j

• Main Authors: Kania, Gabriela, Kwolek, Urszula, Nakai, Keita, Yusa, Shin-ichi, Bednar, Jan, Wójcik, Tomasz, Ch opicki, Stefan, Skórka, Tomasz, Szuwarzy ski, Micha, Szczubia ka, Krzysztof, Kepczynski, Mariusz, Nowakowska, Maria
• Format: Article
• Language: English
• ISSN: 2050-750X; 2050-7518
• DOI: 10.1039/c5tb00182j

Stable polymersomes with semipermeable membranes were prepared by simple mixing of two oppositely charged diblock copolymers containing zwitterionic and cationic (PMPC 20 - b -PMAPTAC 190 ) or anionic (PMPC 20 - b -PAMPS 196 ) blocks. The formation of vesicular structures in the mixed solution of the block copolymers was confirmed by direct observation using the cryo-TEM technique. Superparamagnetic iron oxide nanoparticles coated with a cationic chitosan derivative (SPION/CCh) and decorated with a fluorescent probe molecule were next incorporated into the polymersome structure. The average diameter of SPION/CCh-polymersomes estimated using cryo-TEM was about 250 nm. Surface topography of the SPION/CCh-loaded vesicles was imaged using AFM and the magnetic properties of these objects were confirmed by MFM and MRI measurements. The ability of SPION/CCh-polymersomes to affect T 2 relaxation time in MRI was evaluated based on the measurements of r 2 relaxivity. The obtained value of r 2 (573 ± 10 mM −1 s −1 ) was quite high. The cytotoxicity and intracellular uptake of the SPION/CCh-loaded vesicles into EA.hy926 cells were studied. The results indicate that the SPION/CCh-polymersomes seem to be internalized by vascular endothelium and are not cytotoxic to endothelial cells up to 1 μg Fe per mL. Therefore, it can be suggested that SPION/CCh-polymersomes could prove useful as T 2 contrast agents in the MRI of endothelium. Novel biocompatible polymersomes with semipermeable ionic membranes were used as promising delivery systems.