Abstract
Purpose: :
The purpose of this study is to explore the use of magnetite cationic liposome for nonviral gene transfection to the retinal pigment epithelial cells (RPE).
Methods: :
Magnetite cationic liposome (MAC) was prepared by mixing cationic lipid, plasmid DNA (phrGFP-N1) and magnetite nanoparticles. The concentration of the magnetite nanoparticles used was 2.5, 5, 12.5, 25 or 50 pg/cells. First, the human RPE cell line (ARPE-19) was cultured in 6-well culture plate. The cells were transfected for 5 or 30 minutes using magnetite cationic liposome, with magnet placed under the culture plate at the center of the well (magnetolipofection). Lipofection using lipofectamine2000 was performed as control. Forty eight hours after transfection, GFP positive cells were counted under fluorescence microscope. Second, ARPE-19 was cultured in flask, flask was put up, and horizontal gene tranfection experiment was performed by placing the magnet horizontally. The condition used was same as the first experiment.
Results: :
With any magnetite concentration tested, significantly larger number of GFP-positive cells was observed in the central region of the well, where the magnet was placed, compared with the peripheral region. The number of GFP-positive cells was largest (5 min: 31.7 cells/mm2) when the concentration of magnetite was 25 pg/ml, and it was equivalent to the number of the cells transfected with lipofectamine2000 (27.6 cells/mm2) with vertical gene transfection. However, there was almost no GFP-positive cell observed in horizontal gene transfection experiment when lipofectamine2000 was used, although, with magnetolipofection, targeted transfection to central region (31.4 cells/mm2) was still obtained when magnetite was used in concentration of 25 pg /cells.
Conclusions: :
With magnetolipofection, the area of gene transfection could be controlled by placing the magnet at optional place in vitro. Magnetolipofection has potential to be an experimental or clinical tool, i.e. by targetedly transfecting RPE beneath the macula.
Keywords: gene transfer/gene therapy • retinal pigment epithelium