title: Exploring a new SPION-based MRI contrast agent with excellent water-dispersibility, high specificity to cancer cells and strong MR imaging efficacy.
abstract: Advances in contrast agents have greatly enhanced the sensitivity of magnetic resonance imaging (MRI) technique for early diagnosis of cancer. However, the commercial superparamagnetic iron oxide nanoparticles (SPION)-based contrast agents synthesized by co-precipitation method are not monodisperse with irregular morphologies and ununiform sizes. Other reported SPION-based contrast agents synthesized by solvothermal method or thermal decomposition method are limited by the bad water-dispersibility and low specificity to cancer cells. Herein, we propose a new strategy for exploring SPION-based MRI contrast agents with excellent water-dispersibility and high specificity to cancer cells. The SPION was synthesized by a polyol method and then entrapped into albumin nanospheres (AN). After that, a ligand folic acid (FA) was conjugated onto the surface of the AN to construct a SPION-AN-FA composite. The transmission electron microscope (TEM) and dynamic light scattering (DLS) results indicate that the SPION-AN-FA has a spherical shape, a uniform size and an excellent water-dispersibility (polydispersity index (PDI) <0.05). The results of laser scanning confocal microscope (LSCM) and flow cytometry demonstrate that the SPION-AN-FA nanoparticles are highly specific to MCF-7 and SPC-A-1 cells due to the recognition of ligand FA and folate receptor α (FRα). The r2/r1 value of SPION-AN-FA is around 40, which is much higher than that of Resovist(®) indicating that our SPION-AN-FA has a stronger T2 shortening effect. The T2-weighted images of MCF-7 cells incubated with SPION-AN-FA are significantly darker than those of MCF-7 cells incubated with AN, indicating that our SPION-AN-FA has a strong MR imaging efficacy. In view of the excellent water-dispersibility, the high specificity to cancer cells and the strong MR imaging efficacy, our SPION-AN-FA can be used as a negative MR contrast agent.
authors.affiliation: Key Laboratory of Magnetic Materials and Devices & Division of Functional Materials and Nano Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China.
authors.forename: Xuehua
authors.initials: X
authors.lastname: Ma
authors.affiliation: Key Laboratory of Magnetic Materials and Devices & Division of Functional Materials and Nano Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China.
authors.forename: An
authors.initials: A
authors.lastname: Gong
authors.affiliation: Ningbo No. 2 Hospital, Ningbo, Zhejiang 315010, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.affiliation: Ningbo No. 2 Hospital, Ningbo, Zhejiang 315010, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Magnetic Materials and Devices & Division of Functional Materials and Nano Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China.
authors.forename: Tianxiang
authors.initials: T
authors.lastname: Chen
authors.affiliation: Key Laboratory of Magnetic Materials and Devices & Division of Functional Materials and Nano Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China. Electronic address: shenzheyu@nimte.ac.cn.
authors.forename: Zheyu
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Key Laboratory of Magnetic Materials and Devices & Division of Functional Materials and Nano Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China. Electronic address: aiguo@nimte.ac.cn.
authors.forename: Aiguo
authors.initials: A
authors.lastname: Wu
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival; D003287:Contrast Media / Q000138:chemical synthesis / Q000737:chemistry; D005492:Folic Acid / Q000737:chemistry; D006801:Humans; D061986:MCF-7 Cells; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles / Q000737:chemistry; D012709:Serum Albumin / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D003287:Contrast Media; D058185:Magnetite Nanoparticles; D012709:Serum Albumin; D014867:Water; D005492:Folic Acid
keywords: Excellent water-dispersibility; High specificity to cancer cells; MRI contrast agent; Strong MR imaging efficacy; Superparamagnetic iron oxide nanoparticles