title: Improved gene transfer efficiency of a DNA-lipid-apatite composite layer by controlling the layer molecular composition.
abstract: Surface-mediated nonviral gene transfer systems using biocompatible apatite-based composite layers have potential use in tissue engineering applications. Herein, we investigated a relatively efficient system based on a DNA-lipid-apatite composite layer (DLp-Ap layer): an apatite (Ap) layer with immobilized DNA and lipid (Lp) complexes (DLp complexes). DLp-Ap layers were fabricated on substrates using supersaturated calcium phosphate coprecipitation solutions supplemented with DLp complexes, and the molecular compositions of the DLp-Ap layers were controlled by varying the net DNA concentrations and Lp/DNA ratios in the coprecipitation solutions. Increases in both the DNA concentration and Lp/DNA ratio in the coprecipitation solution increased the DLp complex content of the resulting DLp-Ap layer. However, a higher DLp complex content did not always provide increased gene transfer efficiency to the CHO-K1 cells, because there was a threshold content of approximately 10μg/cm(2). In addition, DLp-Ap layers with similar DLp complex contents exhibited different gene transfer efficiencies, most likely due to the different Lp/DNA ratios in the layers. Notably, the optimized Lp/DNA ratios in the coprecipitation solutions for maximizing the gene transfer efficiency were lower than those of the conventional particle-mediated lipofection systems. These findings will serve as a useful design guide for the preparation of DLp-Ap layers with high gene transfer efficiency.
authors.affiliation: Research Institute for Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku, Tokyo 169-8555, Japan; Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan.
authors.forename: Yushin
authors.initials: Y
authors.lastname: Yazaki
authors.affiliation: Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan. Electronic address: a-oyane@aist.go.jp.
authors.forename: Ayako
authors.initials: A
authors.lastname: Oyane
authors.affiliation: Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan; Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Tsurushima
authors.affiliation: Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Araki
authors.affiliation: Human Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sogo
authors.affiliation: Human Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
authors.forename: Atsuo
authors.initials: A
authors.lastname: Ito
authors.affiliation: Department of Resources and Environmental Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku, Tokyo 169-8555, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamazaki
mesh_terms: D001031:Apatites / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D018014:Gene Transfer Techniques; D008055:Lipids / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning
chemical_list: D001031:Apatites; D008055:Lipids; D004247:DNA
keywords: Apatite; Composite; DNA; Gene transfer; Lipid; Lipofection