title: Synthesis of novel chitosan-silica/CpG oligodeoxynucleotide nanohybrids with enhanced delivery efficiency.
abstract: Chitosan-silica/CpG oligodeoxynucleotide (ODN) nanohybrids were synthesized to stimulate Toll-like receptor 9-mediated induction of interleukin-6 (IL-6). The chitosan-silica hybrid was first synthesized from a mixture of chitosan and 3-glycidoxypropyl trimethoxysilane under acidic conditions via a sol-gel process, and then used to condense CpG ODN2006x3-PD to yield chitosan-silica/CpG ODN nanohybrids. Scanning electron microscopy and atomic force microscopy showed that the chitosan-silica/CpG ODN nanohybrids had an elliptic shape with a diameter of 100-200 nm. After soaking in HAc-NaAc buffer solution (pH5.5), the nanohybrids exhibited sustained release of CpG ODN. When the nanohybrids were separately exposed to 293XL-hTLR9 cells and peripheral blood mononuclear cells, no significant toxicity was observed. An immunochemical assay for cellular uptake revealed that the nanohybrids were taken up by the cells and located in endolysosomes. An enzyme-linked immunosorbent assay for cytokines indicated that the nanohybrids effectively stimulated the induction of IL-6. Chitosan-silica/CpG ODN nanohybrids underwent cellular uptake and enhanced induction of IL-6 to a greater degree than conventional chitosan/CpG ODN nanocomplexes, indicating that they have an enhanced delivery efficiency.
authors.affiliation: JSPS Research Fellow, 8 Ichibancho, Chiyoda-ku, Tokyo 102-8472, Japan. CHEN.Song@nims.go.jp
authors.forename: Song
authors.initials: S
authors.lastname: Chen
authors.forename: Huijie
authors.initials: H
authors.lastname: Zhang
authors.forename: Shanmugavel
authors.initials: S
authors.lastname: Chinnathambi
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Hanagata
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D048271:Chitosan / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry; D057809:HEK293 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015850:Interleukin-6 / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects; D049329:Nanostructures / Q000737:chemistry* / Q000633:toxicity; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000494:pharmacology; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D051217:Toll-Like Receptor 9 / Q000235:genetics / Q000378:metabolism
chemical_list: C403136:3-glycidoxypropyltrimethoxysilane; C408982:CPG-oligonucleotide; D004337:Drug Carriers; D015850:Interleukin-6; D009838:Oligodeoxyribonucleotides; D012821:Silanes; D051217:Toll-Like Receptor 9; D012822:Silicon Dioxide; D048271:Chitosan