title: GFP expression by intracellular gene delivery of GFP-coding fragments using nanocrystal quantum dots.
abstract: Gene therapy is an attractive approach to supplement a deficient gene function. Although there has been some success with specific gene delivery using various methods including viral vectors and liposomes, most of these methods have a limited efficiency or also carry a risk for oncogenesis. We herein report that quantum dots (QDs) conjugated with nuclear localizing signal peptides (NLSP) successfully introduced gene-fragments with promoter elements, which promoted the expression of the enhanced green fluorescent protein (eGFP) gene in mammalian cells. The expression of eGFP protein was observed when the QD/gene-construct was added to the culture media. The gene-expression efficiency varied depending on multiple factors around QDs, such as (1) the reading direction of the gene-fragments, (2) the quantity of gene-fragments attached on the surface of the QD-constructs, (3) the surface electronic charges varied according to the structure of the QD/gene-constructs, and (4) the particle size of QD/gene complex varied according to the structure and amounts of gene-fragments. Using this QD/gene-construct system, eGFP protein could be detected 28 days after the gene-introduction whereas the fluorescence of QDs had disappeared. This system therefore provides another method for the intracellular delivery of gene-fragments without using either viral vectors or specific liposomes.
authors: International Clinical Research Center, Research Institute, International Medical Center of Japan, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-8655, Japan. Department of Pharmacokinetics and Pharmacodynamics, Hospital Pharmacy, Tokyo Medical and Dental University Graduate School, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors: Akiyoshi
authors: A
authors: Hoshino
authors: Noriyoshi
authors: N
authors: Manabe
authors: Kouki
authors: K
authors: Fujioka
authors: Sanshiro
authors: S
authors: Hanada
authors: Masato
authors: M
authors: Yasuhara
authors: Akihiko
authors: A
authors: Kondo
authors: Kenji
authors: K
authors: Yamamoto