Surface Tunable Polymersomes Loaded with Magnetic Contrast Agent and Drug for Image Guided Cancer Therapy

Abstract

Polymersomes with different surface charges were synthesized from polysuccinimide (p) by introducing positively charged polyethylenimine (PEI-P), neutrally charged polyethylene glycol (PEG-P), and negatively charged glycine (GLY-P) to the polymer backbone polysuccinimide (P). Then, the polymersomes were prepared with super paramagnetic iron nanoparticles (SPIONs) to obtain PEI-P encapsulating SPIONs (PEI-PS), PEG-P encapsulating SPIONs (PEG-PS), and GLY-P encapsulating SPIONs (GLY-PS), respectively. The average particle sizes of GLY-PS, PEG-PS, and PEI-PS were analyzed by dynamic light scattering, and it was around 163 nm, 105 nm, and 285 nm, respectively. The surface charges of GLY-PS, PEG-PS, and PEI-PS was found to be -29.5, -18.9, and +44, respectively. The presence of PEI, PEG, and GLY in the polymer backbone was confirmed with nuclear magnetic resonance (NMR). The GLY-PS, PEG-PS, and PEI-PS were loaded with the anticancer drug paclitaxel during the preparation. The drug release from the PEG-PS was faster compared to GLY-PS and PEI-PS. An in vivo hemi-spleen mouse metastatic liver model was established and imaged with MRI after intravenous administration of GLY-PS, PEG-PS, and PEI-PS. From the T2-weighted imaging, it was evident that PEG-PS accumulated in the spleen and liver more efficiently than the other charged formulations of GLY-PS and PEI-PS. From this study, the nanoparticle-based delivery and imaging of anti-cancer drugs could be effectively demonstrated simultaneously.