title: Ultrahigh relaxivity and safe probes of manganese oxide nanoparticles for in vivo imaging.
abstract: Mn-based nanoparticles (NPs) have emerged as new class of probes for magnetic resonance imaging due to the impressive contrast ability. However, the reported Mn-based NPs possess low relaxivity and there are no immunotoxicity data regarding Mn-based NPs as contrast agents. Here, we demonstrate the ultrahigh relaxivity of water protons of 8.26 mM(-1) s(-1) from the Mn3O4 NPs synthesized by a simple and green technique, which is twice higher than that of commercial gadolinium (Gd)-based contrast agents (4.11 mM(-1) s(-1)) and the highest value reported to date for Mn-based NPs. We for the first time demonstrate these Mn3O4 NPs biocompatibilities both in vitro and in vivo are satisfactory based on systematical studies of the intrinsic toxicity including cell viability of human nasopharyngeal carcinoma cells, normal nasopharyngeal epithelium, apoptosis in cells and in vivo immunotoxicity. These findings pave the way for the practical clinical diagnosis of Mn based NPs as safe probes for in vivo imaging.
authors.affiliation: 1] State Key Laboratory of Optoelectronic Materials and Technologies, Institute of Optoelectronic and Functional Composite Materials, Nanotechnology Research Center, School of Physics & Engineering, Sun Yat-sen University, Guangzhou 510275, Guangdong, P. R. China [2] State Key Laboratory of Oncology in South China, Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, Guangzhou 510060, P. R. China [3].
authors.forename: J
authors.initials: J
authors.lastname: Xiao
authors.forename: X M
authors.initials: XM
authors.lastname: Tian
authors.forename: C
authors.initials: C
authors.lastname: Yang
authors.forename: P
authors.initials: P
authors.lastname: Liu
authors.forename: N Q
authors.initials: NQ
authors.lastname: Luo
authors.forename: Y
authors.initials: Y
authors.lastname: Liang
authors.forename: H B
authors.initials: HB
authors.lastname: Li
authors.forename: D H
authors.initials: DH
authors.lastname: Chen
authors.forename: C X
authors.initials: CX
authors.lastname: Wang
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: G W
authors.initials: GW
authors.lastname: Yang
mesh_terms: D000818:Animals; D003287:Contrast Media; D004195:Disease Models, Animal; D005260:Female; D064593:Heterografts; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D017895:Manganese Compounds / Q000737:chemistry / Q000493:pharmacokinetics; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity / Q000648:ultrastructure; D051379:Mice; D009369:Neoplasms / Q000175:diagnosis; D010087:Oxides / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D003287:Contrast Media; D017895:Manganese Compounds; D010087:Oxides; C027424:manganese oxide