title: Highly Effective Non-Viral Antitumor Gene Therapy System Comprised of Biocompatible Small Plasmid Complex Particles Consisting of pDNA, Anionic Polysaccharide, and Fully Deprotected Linear Polyethylenimine.
abstract: We have reported that ternary complexes of plasmid DNA with conventional linear polyethylenimine (l-PEI) and certain polyanions were very stably dispersed, and, with no cryoprotectant, they could be freeze-dried and re-hydrated without the loss of transfection ability. These properties enabled the preparation of a concentrated suspension of very small pDNA complex, by preparing the complexes at highly diluted conditions, followed by condensation via lyophilization-and-rehydration procedure. Recently, a high potency linear polyethylenimine having no residual protective groups, i.e., Polyethylenimine "Max" (PEI "Max"), is available, which has been reported to induce much higher gene expression than conventional l-PEI. We tried to prepare the small DNA/PEI "Max"/polyanion complexes by a similar freeze-drying method. Small complex particles could be obtained without apparent aggregation, but transfection activity of the rehydrated complexes was severely reduced. Complex-preparation conditions were investigated in details to achieve the freeze-dried DNA/PEI "Max"/polyanion small ternary complexes with high transfection efficiency. DNA/PEI "Max"/polyanion complexes containing cytokine-coding plasmids were then prepared, and their anti-tumor therapeutic efficacy was examined in tumor-bearing mice.
authors.affiliation: Japan Anti-tuberculosis Association, Shin-Yamanote Hospital, 3-6-1 Suwa-cho, Higashimurayama, Tokyo 189-0021, Japan. drkoyama@vivid.ocn.ne.jp.|Graduate School of Life and Environmental Sciences, Osaka Prefecture University 1-58 Rinku-oraikita, Izumisano, Osaka 598-8531, Japan. drkoyama@vivid.ocn.ne.jp.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Koyama
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University 1-58 Rinku-oraikita, Izumisano, Osaka 598-8531, Japan. sugiura@vet.osakafu-u.ac.jp.
authors.forename: Kikuya
authors.initials: K
authors.lastname: Sugiura
authors.affiliation: Department of Home Economics, Otsuma Women's University, 12 Sanbancho, Chiyoda-ku, Tokyo 102-8357, Japan. yoshihara@otsuma.ac.jp.
authors.forename: Chieko
authors.initials: C
authors.lastname: Yoshihara
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University 1-58 Rinku-oraikita, Izumisano, Osaka 598-8531, Japan. inaba@vet.osakafu-u.ac.jp.
authors.forename: Toshio
authors.initials: T
authors.lastname: Inaba
authors.affiliation: Japan Anti-tuberculosis Association, Shin-Yamanote Hospital, 3-6-1 Suwa-cho, Higashimurayama, Tokyo 189-0021, Japan. tomoko_ito@nifty.com.|Graduate School of Life and Environmental Sciences, Osaka Prefecture University 1-58 Rinku-oraikita, Izumisano, Osaka 598-8531, Japan. tomoko_ito@nifty.com.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ito
keywords: Polyethylenimine “Max”; antitumor; chondroitin sulfate; cytokine; freeze-drying; hyaluronic acid; nanoparticle; non-viral; plasmid; transfection