title: Synthesis and characterization of pore size-tunable magnetic mesoporous silica nanoparticles.
abstract: Magnetic mesoporous silica nanoparticles (M-MSNs) are emerging as one of the most appealing candidates for theranostic carriers. Herein, a simple synthesis method of M-MSNs with a single Fe(3)O(4) nanocrystal core and a mesoporous shell with radially aligned pores was elaborated using tetraethyl orthosilicate (TEOS) as silica source, cationic surfactant CTAB as template, and 1,3,5-triisopropylbenzene (TMB)/decane as pore swelling agents. Due to the special localization of TMB during the synthesis process, the pore size was increased with added TMB amount within a limited range, while further employment of TMB lead to severe particle coalescence and not well-developed pore structure. On the other hand, when a proper amount of decane was jointly incorporated with limited amounts of TMB, effective pore expansion of M-MSNs similar to that of analogous mesoporous silica nanoparticles was realized. The resultant M-MSN materials possessed smaller particle size (about 40-70 nm in diameter), tunable pore sizes (3.8-6.1 nm), high surface areas (700-1100 m(2)/g), and large pore volumes (0.44-1.54 cm(3)/g). We also demonstrate their high potential in conventional DNA loading. Maximum loading capacity of salmon sperm DNA (375 mg/g) was obtained by the use of the M-MSN sample with the largest pore size of 6.1 nm.
authors.affiliation: Nano Biomedical Research Center, Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China. jixizhang1985@gmail.com
authors.forename: Jixi
authors.initials: J
authors.lastname: Zhang
authors.forename: Xu
authors.initials: X
authors.lastname: Li
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Rosenholm
authors.forename: Hong-chen
authors.initials: HC
authors.lastname: Gu
mesh_terms: D000818:Animals; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D004247:DNA / Q000008:administration & dosage*; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D016062:Porosity; D012474:Salmon; D012822:Silicon Dioxide / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D002593:Cetrimonium Compounds; D013501:Surface-Active Agents; D012822:Silicon Dioxide; D004247:DNA; D000077286:Cetrimonium