Enhancement of transfection efficiency through rapid and noncovalent post-PEGylation of poly(dimethylaminoethyl methacrylate)/DNA complexes.
OBJECTIVE
The aim of this work was to develop a new strategy to introduce poly(ethylene glycol) (PEG) into methacrylate-based polymer/ DNA complexes in order to produce hemocompatible particles able to transfect cells in the presence of serum.


METHODS
Atom transfer radical polymerization was used to synthesize a well-defined poly(2-(dimethylamino)ethyl methacrylate) homopolymer (PDMAEMA) and a poly(2-(dimethylamino)ethyl methacrylate-b-poly(ethylene glycol) alpha-methyl ether, omega-methacrylate) palm-tree-like copolymer (P(DMAEMA-b-MAPEG)). The complexes obtained by self assembly of the pCMVbeta plasmid and the polymers were used to transfect Cos-7 cells. Their physical properties--particle size and zeta potential--were characterized respectively by dynamic light scattering and electrophoretic mobility measurements. Ex vivo hemocompatibility was also determined.


RESULTS
The PDMAEMA/pCMVbeta complexes transfected Cos-7 cells exclusively in the absence of serum. Although the P(DMAEMA-bMAPEG) copolymer had no transfection activity per se, the addition of the latter to pre-formed PDMAEMA/DNA complexes significantly enhanced the activity and allowed transfection even in the presence of serum. The presence of palm-tree-like copolymers also improved the hemocompatibility properties of the complexes. No effect on platelet counts was observed for P(DMAEMA-b-MAPEG)/pCMVbeta complexes, whereas a decrease of platelets was clearly observed when blood cells were incubated with PDMAEMA/pCMVbeta complexes.


CONCLUSIONS
Such a synergistic effect of noncovalent PEGylation of poly(amino methacrylate)/DNA complexes allows a new and versatile approach to tune up transfection efficiency.
Pirotton
Sabine
S
Research Unit of Cell Biology (URBC), University of Namur (FUNDP), Namur, Belgium.
Muller
Caroline
C
Pantoustier
Nadège
N
Botteman
François
F
Collinet
Sébastien
S
Grandfils
Christian
C
Dandrifosse
Guy
G
Degée
Philippe
P
Dubois
Philippe
P
Raes
Martine
M
D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004247:DNA / Q000737:chemistry*; D004903:Erythrocyte Aggregation; D006461:Hemolysis; D008689:Methacrylates / Q000737:chemistry; D009757:Nylons / Q000737:chemistry; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D014162:Transfection / Q000379:methods*
D008689:Methacrylates; D009757:Nylons; D011109:Polymethacrylic Acids; C407037:poly(2-(dimethylamino)ethyl methacrylate); D011092:Polyethylene Glycols; D004247:DNA