Facile synthesis and functionalization of manganese oxide nanoparticles for targeted T1-weighted tumor MR imaging.

We report the polyethyleneimine (PEI)-enabled synthesis and functionalization of manganese oxide (Mn3O4) nanoparticles (NPs) for targeted tumor magnetic resonance (MR) imaging in vivo. In this work, monodispersed PEI-coated Mn3O4 NPs were formed by decomposition of acetylacetone manganese via a solvothermal approach. The Mn3O4 NPs with PEI coating were sequentially conjugated with fluorescein isothiocyanate, folic acid (FA)-linked polyethylene glycol (PEG), and PEG monomethyl ether. Followed by final acetylation of the remaining PEI surface amines, multifunctional Mn3O4 NPs were formed and well characterized. We show that the formed multifunctional Mn3O4 NPs with a mean diameter of 8.0 nm possess good water-dispersibility, colloidal stability, and cytocompatibility and hemocompatibility in the given concentration range. Flow cytometry and confocal microscopic observation reveal that the multifunctional Mn3O4 NPs are able to target FA receptor-overexpressing cancer cells in vitro. Importantly, the FA-targeted Mn3O4 NPs can be used as a nanoprobe for efficient T1-weighted MR imaging of cancer cells in vitro and the xenografted tumor model in vivo via an active FA-mediated targeting pathway. With the facile PEI-enabled formation and functionalization, the developed PEI-coated Mn3O4 NPs may be modified with other biomolecules for different biomedical imaging applications.

Luo Y ，Yang J ，Li J ，Yu Z ，Zhang G ，Shi X ，Shen M ... -  《-》

Polyethyleneimine-Coated Manganese Oxide Nanoparticles for Targeted Tumor PET/MR Imaging.

Zhu J ，Li H ，Xiong Z ，Shen M ，Conti PS ，Shi X ，Chen K ... -  《-》

Polyethyleneimine-mediated synthesis of folic acid-targeted iron oxide nanoparticles for in vivo tumor MR imaging.

We report a facile polyethyleneimine (PEI)-mediated approach to synthesizing folic acid (FA)-targeted magnetic iron oxide nanoparticles (Fe3O4 NPs) for in vivo magnetic resonance (MR) imaging of tumors. In this study, stable PEI-coated Fe3O4 NPs were prepared by a one-pot hydrothermal route. The aminated Fe3O4 NPs with PEI coating enabled covalent conjugation of fluorescein isothiocyanate (FI) and folate-conjugated polyethylene glycol (PEG) with one end of carboxyl groups (FA-PEG-COOH). Followed by final acetylation, FA-targeted PEGylated Fe3O4 NPs (Fe3O4-PEI-Ac-FI-PEG-FA NPs) were formed. The formed multifunctional Fe3O4 NPs were characterized via different techniques. We show that the PEI-mediated approach along with the PEGylation conjugation enables the generation of water-dispersible and stable multifunctional Fe3O4 NPs, and the particles are quite cytocompatible and hemocompatible in the given concentration range as confirmed by in vitro cytotoxicity assay, cell morphology observation, and hemolysis assay. In addition, flow cytometry and confocal microscopy data show that the multifunctional Fe3O4 NPs are able to target a model cancer cell line (KB cells) overexpressing FA receptors in vitro. Importantly, the FA-targeted Fe3O4 NPs are able to be used as an efficient nanoprobe for MR imaging of cancer cells in vitro and a xenografted tumor model in vivo via an active FA targeting pathway. With the facile PEI-mediated formation strategy and PEGylation conjugation chemistry, the Fe3O4 NPs may be multifunctionalized with other biological ligands for MR imaging of different biological systems.

Li J ，Zheng L ，Cai H ，Sun W ，Shen M ，Zhang G ，Shi X ... -  《-》

Facile synthesis of RGD peptide-modified iron oxide nanoparticles with ultrahigh relaxivity for targeted MR imaging of tumors.

Hu Y ，Li J ，Yang J ，Wei P ，Luo Y ，Ding L ，Sun W ，Zhang G ，Shi X ，Shen M ... -  《-》

Facile synthesis of folic acid-functionalized iron oxide nanoparticles with ultrahigh relaxivity for targeted tumor MR imaging.

Li J ，Hu Y ，Yang J ，Sun W ，Cai H ，Wei P ，Sun Y ，Zhang G ，Shi X ，Shen M ... -  《-》