Development of sensitive contrast agents for positive magnetic resonance (MR) imaging of biosystems still remains a great challenge. Herein, we report a facile process to construct hybrid alginate (AG) nanogels (NGs) loaded with manganese oxide (Mn3O4) nanoparticles (NPs) for enhanced tumor MR imaging. In this study, polyethylenimine (PEI)-modified Mn3O4 NPs (PEI-Mn3O4 NPs) were prepared and used as a crosslinker to chemically crosslink the AG NGs with activated carboxyl groups formed via a double emulsion process. The obtained AG/PEI-Mn3O4 NGs with a mean size (dTEM) of about 141.6 nm display excellent colloidal stability in aqueous solution and good cytocompatibility in the studied concentration range. Moreover, MR relaxometry measurements indicate that the hybrid NGs have a high r1 relaxivity of 26.12 mM-1s-1, which is about 43 times higher than that of PEI-Mn3O4 NPs. Furthermore, the AG/PEI-Mn3O4 NGs presented better performances for MR imaging of cancer cells in vitro and a subcutaneous tumor model in vivo than PEI-Mn3O4 NPs with PEI surface amine acetylated. With the good biosafety confirmed by histological examinations, the developed AG/PEI-Mn3O4 NGs may be potentially used as an efficient contrast agent for enhanced MR imaging of different biosystems.

Construction of hybrid alginate nanogels loaded with manganese oxide nanoparticles for enhanced tumor MR imaging

255th National Meeting (2018)

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