TY - JOUR
T1 - Temperature-responsive polymeric carriers incorporating hydrophobic monomers for effective transfection in small doses
AU - Takeda, Naoya
AU - Nakamura, Emiko
AU - Yokoyama, Masayuki
AU - Okano, Teruo
PY - 2004/3/5
Y1 - 2004/3/5
N2 - A series of thermoresponsive ternary random copolymers, poly[N-isopropylacrylamide (PIPAAm)-co-(dimethylamino)ethylmethacrylate (DMAEMA)-co-butylmethacrylate (BMA)], was synthesized and their in vitro gene transfection efficiency in cell culture was evaluated. A control copolymer containing 20 mol% DMAEMA units, IP-20D (mole ratio of IPAAm/DMAEMA/BMA=80/20/0 in feed, no BMA units) was inert in transfection. In contrast, copolymer IP-20D-10B (IPAAm/DMAEMA/BMA=70/20/10 in feed) effectively transfected plasmid DNA into COS-1 cell cultures even under small dosing conditions of 0.1 μg of plasmid DNA per well in a 96-well plate, suggesting that incorporation of the appropriate amount of hydrophobic unit is crucial to transfection efficiency. Gene expression was much more significant when transfected by the IP-20D-10B carrier in comparison with control homopolymer poly-DMAEMA, and almost equal to that of the highly competent lipid carrier, LipofectAMINE PLUS™. Furthermore, the transfection efficiency of IP-20D-10B is altered in a thermally responsive manner. By temporarily lowering the cell culture incubation temperature to 20°C in the posttransfection period, gene expression doubled over that for incubation temperature at 37°C. The DNA EtBr intercalation assay suggested that DNA affinity for IP-20D-10B is decreased by lowering incubation temperature, implying that the thermally regulated gene expression could provide more efficient DNA release from the polymeric carrier.
AB - A series of thermoresponsive ternary random copolymers, poly[N-isopropylacrylamide (PIPAAm)-co-(dimethylamino)ethylmethacrylate (DMAEMA)-co-butylmethacrylate (BMA)], was synthesized and their in vitro gene transfection efficiency in cell culture was evaluated. A control copolymer containing 20 mol% DMAEMA units, IP-20D (mole ratio of IPAAm/DMAEMA/BMA=80/20/0 in feed, no BMA units) was inert in transfection. In contrast, copolymer IP-20D-10B (IPAAm/DMAEMA/BMA=70/20/10 in feed) effectively transfected plasmid DNA into COS-1 cell cultures even under small dosing conditions of 0.1 μg of plasmid DNA per well in a 96-well plate, suggesting that incorporation of the appropriate amount of hydrophobic unit is crucial to transfection efficiency. Gene expression was much more significant when transfected by the IP-20D-10B carrier in comparison with control homopolymer poly-DMAEMA, and almost equal to that of the highly competent lipid carrier, LipofectAMINE PLUS™. Furthermore, the transfection efficiency of IP-20D-10B is altered in a thermally responsive manner. By temporarily lowering the cell culture incubation temperature to 20°C in the posttransfection period, gene expression doubled over that for incubation temperature at 37°C. The DNA EtBr intercalation assay suggested that DNA affinity for IP-20D-10B is decreased by lowering incubation temperature, implying that the thermally regulated gene expression could provide more efficient DNA release from the polymeric carrier.
KW - Gene delivery
KW - Poly(N-isopropylacrylamide)
KW - Polymer carrier
KW - Thermoresponsive
KW - Transfection
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U2 - 10.1016/j.jconrel.2003.12.001
DO - 10.1016/j.jconrel.2003.12.001
M3 - Article
C2 - 14980782
AN - SCOPUS:1242338833
VL - 95
SP - 343
EP - 355
JO - Journal of Controlled Release
JF - Journal of Controlled Release
SN - 0168-3659
IS - 2
ER -