title: Novel biocompatible cationic copolymers based on polyaspartylhydrazide being potent as gene vector on tumor cells.
abstract: BACKGROUND
  The reaction between alpha,beta-poly(aspartylhydrazide) (PAHy), a water soluble synthetic polymer and 3-(carboxypropyl)trimethyl-ammonium chloride (CPTACl) produced copolymers bearing permanent positive charges (PAHy-CPTA) with molecular weight of 10 kDa and PAHy-CPTA copolymers differing in positive charge amount (18-58%) were chosen for biological investigations.
  
  
  METHODS
  Biophysical properties of DNA/PAHy-CPTA polyplexes were evaluated in terms of DNA condensation, zeta potential and size distribution. Cytotoxicity studies on Neuro2A murine neuroblastoma cells evidenced absence of toxicity of these copolymers up to 300 microg/ml unlike linear polyethylenimine (LPEI) that was highly toxic already at 20 microg/ml.
  
  
  CONCLUSIONS
  PAHy-CPTA copolymers did not induce any erythrocyte aggregation up to 1 mg/ml. Cellular interaction studies of PAHy-CPTA polyplexes evidenced a faster binding of these polyplexes with cells compared to DNA/LPEI polyplexes. The in vitro transfection ability of PAHy-CPTA polyplexes was strongly affected by experimental conditions reaching about 10% of the transfection efficiency of optimized LPEI polyplexes.
  
  
  CONCLUSIONS
  Finally, in vivo application studies confirmed the biocompatibility of PAHy-CPTA copolymers. With LPEI, clear signs of microvesicular fatty liver were observed and with LPEI polyplexes significant weight loss. In strong contrast, PAHy-CPTA did not induce histopathological changes or weight loss.
authors.affiliation: Pharmaceutical Biology-Biotechnology, Department of Pharmacy, Ludwig-Maximilians-Universität, Butenandtstr. 5-13, 81377, Munich, Germany. manfred.ogris@cup.uni-muenchen.de
authors.forename: Manfred
authors.initials: M
authors.lastname: Ogris
authors.forename: Arun K
authors.initials: AK
authors.lastname: Kotha
authors.forename: Nicole
authors.initials: N
authors.lastname: Tietze
authors.forename: Ernst
authors.initials: E
authors.lastname: Wagner
authors.forename: Fabio Salvatore
authors.initials: FS
authors.lastname: Palumbo
authors.forename: Gaetano
authors.initials: G
authors.lastname: Giammona
authors.forename: Gennara
authors.initials: G
authors.lastname: Cavallaro
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001835:Body Weight / Q000187:drug effects; D002412:Cations; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D056486:Chemical and Drug Induced Liver Injury; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004903:Erythrocyte Aggregation / Q000187:drug effects; D005260:Female; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008107:Liver Diseases / Q000473:pathology; D051379:Mice; D008970:Molecular Weight; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009690:Nucleic Acid Conformation; D010316:Particle Size; D010455:Peptides / Q000737:chemistry / Q000633:toxicity*; D011094:Polyethyleneimine / Q000737:chemistry / Q000633:toxicity*; D011108:Polymers / Q000737:chemistry / Q000633:toxicity*; D014162:Transfection / Q000379:methods*
chemical_list: D001672:Biocompatible Materials; D002412:Cations; D010455:Peptides; D011108:Polymers; C442699:poly(aspartylhydrazide); D011094:Polyethyleneimine; D004247:DNA