title: Stability of chitosan-pDNA complex powder prepared by supercritical carbon dioxide process.
abstract: The present study examined the stability of a gene in powders prepared with supercritical carbon dioxide (CO(2)) from the viewpoints of the ternary structure of DNA and in vivo transfection potential. An aqueous chitosan-pCMV-Luc complex solution containing mannitol was injected into the stream of a supercritical CO(2)/ethanol admixture to precipitate a gene powder. The obtained gene powders and gene solutions were placed in stability chambers at 25 or 40 degrees C for 4 weeks. The integrity and transfection potency of the gene were examined by electrophoresis and in vivo pulmonary transfection study in mice. The supercritical CO(2) process decreased the supercoiled DNA during the manufacturing process; however, the decrease in the remaining supercoiled and open circular DNA in the powders during storage was much slower than that in solutions. In addition, the powders had higher transfection potency than the solutions containing the same amount of DNA. The effect of chitosan on the stability of DNA in solutions was not obvious in the solutions but it improved the stability of DNA in powders during manufacturing and storage. Thus, a gene powder with a cationic vector is a promising ready-to-use formulation for inhalation therapy of pulmonary diseases.
authors.affiliation: Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan. okamotoh@ccmfs.meijo-u.ac.jp
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Okamoto
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sakakura
authors.forename: Keiko
authors.initials: K
authors.lastname: Shiraki
authors.forename: Kumiko
authors.initials: K
authors.lastname: Oka
authors.forename: Seiko
authors.initials: S
authors.lastname: Nishida
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Todo
authors.forename: Kotaro
authors.initials: K
authors.lastname: Iida
authors.forename: Kazumi
authors.initials: K
authors.lastname: Danjo
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000032:analysis / Q000138:chemical synthesis*; D025924:Chromatography, Supercritical Fluid / Q000295:instrumentation / Q000379:methods*; D004247:DNA / Q000032:analysis / Q000138:chemical synthesis* / Q000235:genetics; D004270:DNA, Circular / Q000032:analysis / Q000138:chemical synthesis; D004278:DNA, Superhelical / Q000032:analysis / Q000138:chemical synthesis; D004355:Drug Stability; D005260:Female; D051379:Mice; D008813:Mice, Inbred ICR; D010957:Plasmids / Q000032:analysis / Q000138:chemical synthesis / Q000235:genetics; D011208:Powders
chemical_list: D004270:DNA, Circular; D004278:DNA, Superhelical; D011208:Powders; D002245:Carbon Dioxide; D004247:DNA; D048271:Chitosan