title: Sound packing DNA: packing open circular DNA with low-intensity ultrasound.
abstract: Supercoiling DNA (folding DNA into a more compact molecule) from open circular forms requires significant bending energy. The double helix is coiled into a higher order helix form; thus it occupies a smaller footprint. Compact packing of DNA is essential to improve the efficiency of gene delivery, which has broad implications in biology and pharmaceutical research. Here we show that low-intensity pulsed ultrasound can pack open circular DNA into supercoil form. Plasmid DNA subjected to 5.4 mW/cm(2) intensity ultrasound showed significant (p-values <0.001) supercoiling compared to DNA without exposure to ultrasound. Radiation force induced from ultrasound and dragging force from the fluid are believed to be the main factors that cause supercoiling. This study provides the first evidence to show that low-intensity ultrasound can directly alter DNA topology. We anticipate our results to be a starting point for improved non-viral gene delivery.
authors.affiliation: Department of Pathology, Tumor Immunity Medical Research Center, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: DongHee
authors.initials: D
authors.lastname: Park
authors.affiliation: Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, Korea.
authors.forename: Bong-Kwang
authors.initials: BK
authors.lastname: Jung
authors.affiliation: School of Electronic Electrical Engineering, Sungkyunkwan University, Suwon, Korea.
authors.forename: Hyunjin
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Gangwon-do, Korea.
authors.forename: Hyungbeen
authors.initials: H
authors.lastname: Lee
authors.affiliation: School of Public Health, Harvard University, Boston, Massachusetts, U.S.A.
authors.forename: Gyudo
authors.initials: G
authors.lastname: Lee
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Gangwon-do, Korea.
authors.forename: Jingam
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Gangwon-do, Korea.
authors.forename: Unchul
authors.initials: U
authors.lastname: Shin
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Gangwon-do, Korea.
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Won
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Gangwon-do, Korea.
authors.forename: Yong Jun
authors.initials: YJ
authors.lastname: Jo
authors.affiliation: Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Chang
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Gangwon-do, Korea.
authors.forename: Sangwoo
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Bio-convergence Engineering, Korea University, Seoul, Korea.
authors.forename: Daesung
authors.initials: D
authors.lastname: Yoon
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Gangwon-do, Korea.
authors.forename: Jongbum
authors.initials: J
authors.lastname: Seo
authors.affiliation: Department of Pathology, Tumor Immunity Medical Research Center, Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Chul-Woo
authors.initials: CW
authors.lastname: Kim
mesh_terms: D004270:DNA, Circular / Q000737:chemistry*; D004278:DNA, Superhelical / Q000737:chemistry*; D049452:Green Fluorescent Proteins / Q000235:genetics; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D013010:Sonication
chemical_list: D004270:DNA, Circular; D004278:DNA, Superhelical; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins