title: Structure-property relationships in manganese oxide--mesoporous silica nanoparticles used for T1-weighted MRI and simultaneous anti-cancer drug delivery.
abstract: The extremely low longitudinal relaxivity (r(1)) of manganese oxide has severely impeded their substitution for cytotoxic gadolinium-based contrast agents for safe clinical magnetic resonance imaging (MRI). Here, we report on a synthetic strategy of chemical oxidation/reduction reaction in-situ in mesopores, followed by hydrogen reduction, for the fabrication of non-toxic manganese oxide/MSNs-based MRI-T(1) contrast agents with highly comparable imaging performance to commercial Gd-based agents. This strategy involves a "soft-templating" process to prepare mesoporous silica nanoparticles, in-situ reduction of MnO(4)(-) by the "soft templates" in mesopores and heat treatment under reducing atmosphere, to disperse manganese oxide nanoparticles within mesopores. This special nanostructure combines the merits of nanopores for maximum manganese paramagnetic center accessibility for water molecules for enhanced MRI performance and encapsulation/sustained release/intracellular delivery of drugs. The synthesized manganese oxide/MSNs were successfully assessed as a high performance contrast agent for MRI-T(1) both in intro and in vivo, and meanwhile, was also demonstrated as an effective anti-cancer drug delivery (doxorubicin) vehicle, therefore, a family of manganese-based theranostics was successfully demonstrated based on the manganese oxide/MSNs composite.
authors.affiliation: State Key of Laboratory of High Performance Ceramic and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Science, 1295 Ding-xi Road, Shanghai 200050, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Hangrong
authors.initials: H
authors.lastname: Chen
authors.forename: Shengjian
authors.initials: S
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Shikuan
authors.initials: S
authors.lastname: Sun
authors.forename: Qianjun
authors.initials: Q
authors.lastname: He
authors.forename: Ming
authors.initials: M
authors.lastname: Ma
authors.forename: Xia
authors.initials: X
authors.lastname: Wang
authors.forename: Huixia
authors.initials: H
authors.lastname: Wu
authors.forename: Lingxia
authors.initials: L
authors.lastname: Zhang
authors.forename: Linlin
authors.initials: L
authors.lastname: Zhang
authors.forename: Jianlin
authors.initials: J
authors.lastname: Shi
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D004337:Drug Carriers / Q000737:chemistry / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D017895:Manganese Compounds / Q000737:chemistry* / Q000378:metabolism; D008422:Materials Testing; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D009369:Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D009374:Neoplasms, Experimental / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D010087:Oxides / Q000737:chemistry* / Q000378:metabolism; D012822:Silicon Dioxide / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D004337:Drug Carriers; D017895:Manganese Compounds; D010087:Oxides; C027424:manganese oxide; D012822:Silicon Dioxide