Neutral liposome-mediated delivery process of fluorescein-modified oligonucleotides in cultured human keratinocytes.
We propose a model of the intracellular delivery process in which fluorescein-labeled natural oligonucleotides (F-DNA) are transferred into the nuclei of cultured human keratinocytes. By encapsulation in neutral multilamellar lecithin liposomes, the F-DNA appeared to be protected against intracellular interactions with cellular materials and nuclease attacks in the cytoplasm during the process. The intracellular behavior of F-DNA and fluorescent phospholipid-labeled liposomes was observed by means of fluorescence analysis. Results showed that: F-DNA encapsulated in neutral multilamellar liposomes reached the cellular nuclei more efficiently than either free F-DNA, or F-DNA in unilamellar liposomes; the liposomal membranes appeared to be left in the cytoplasm. The reaction of F-DNA with complementary DNA was suggested by a rapid quenching of the fluorescence in the nucleus. In addition, the fluorescence decrease was evidently suppressed in the cytoplasm, indicating a protective effect of the neutral multilamellar liposomes against the interaction of F-DNA with cytoplasmic materials. The application of these findings to 'photo'-antisense studies has been discussed, where suppression of a gene expression is attempted by using oligonucleotide-attached fluorescein with the aid of a photo-induced covalent binding property.
Sasaki
M
M
Research Institute of Science and Technology, Tokai University, 1117 Kitakaname, Hiratsuka, 259-1292, Kanagawa, Japan. ssm@sol.rist.u-tokai.ac.jp
Hayashi
J
J
Fujii
M
M
Koizumi
K
K
Fujita
H
H
Kobayashi
M
M
Kawakubo
Y
Y
Ito
A
A
D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D003593:Cytoplasm / Q000378:metabolism* / Q000648:ultrastructure; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D003851:Deoxyribonucleases / Q000378:metabolism; D016503:Drug Delivery Systems; D019793:Fluorescein / Q000032:analysis; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D008081:Liposomes; D009841:Oligonucleotides / Q000008:administration & dosage* / Q000493:pharmacokinetics*
D018076:DNA, Complementary; D008081:Liposomes; D009841:Oligonucleotides; D004247:DNA; D003851:Deoxyribonucleases; D019793:Fluorescein