title: Enhancement of transfection efficiency through rapid and noncovalent post-PEGylation of poly(dimethylaminoethyl methacrylate)/DNA complexes.
abstract: 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.
authors.affiliation: Research Unit of Cell Biology (URBC), University of Namur (FUNDP), Namur, Belgium.
authors.forename: Sabine
authors.initials: S
authors.lastname: Pirotton
authors.forename: Caroline
authors.initials: C
authors.lastname: Muller
authors.forename: Nadège
authors.initials: N
authors.lastname: Pantoustier
authors.forename: François
authors.initials: F
authors.lastname: Botteman
authors.forename: Sébastien
authors.initials: S
authors.lastname: Collinet
authors.forename: Christian
authors.initials: C
authors.lastname: Grandfils
authors.forename: Guy
authors.initials: G
authors.lastname: Dandrifosse
authors.forename: Philippe
authors.initials: P
authors.lastname: Degée
authors.forename: Philippe
authors.initials: P
authors.lastname: Dubois
authors.forename: Martine
authors.initials: M
authors.lastname: Raes
mesh_terms: 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*
chemical_list: D008689:Methacrylates; D009757:Nylons; D011109:Polymethacrylic Acids; C407037:poly(2-(dimethylamino)ethyl methacrylate); D011092:Polyethylene Glycols; D004247:DNA