Interaction between cells and poly(ethylene glycol)-lipid conjugates.
Eight types of poly(ethylene glycol)-lipid(PEG-lipids) carrying different lipid tails were synthesized. These PEG-lipids were labeled with fluorescein isothiocyanate (FITC-PEG-lipids) to examine their interaction with cells and to quantitatively determine amounts of PEG-lipids bound on the cell surface. FITC-PEG-lipids spontaneously anchored to the cell membrane within 15 min without loss of cell viability. The type of lipid had very little effect on the anchoring rates, while an increase in the hydrophobicity of the lipid portion of the PEG-lipids slowed their dissociation rates. Densities of FITC-PEG-lipids on the cell surface ranged from 1 × 10(-3) to 1 × 10(-2)molecules/nm(2), depending on the kinds of lipids employed. The relationship between the stability of the lipids on the cell membrane and the hydrophobicity of the lipid moieties will give a basis for the selection of a hydrophobic moiety in PEG-lipid conjugates for use in specific applications.
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Toru
T
Itagaki
Department of Reparative Materials, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto 606-8507, Japan.
Yusuke
Y
Arima
Department of Reparative Materials, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto 606-8507, Japan.
Rei
R
Kuwabara
Department of Surgical Oncology, Graduate School of Medicine, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
Narufumi
N
Kitamura
Department of Reparative Materials, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto 606-8507, Japan. Electronic address: iwata@frontier.kyoto-u.ac.jp.
Hiroo
H
Iwata
D045744:Cell Line, Tumor; D057809:HEK293 Cells; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*
D008055:Lipids; D011092:Polyethylene Glycols
Amphiphilic polymer; Cell surface modification; Hydrophobic interaction; Poly(ethylene glycol)-lipid conjugates