title: [Synthesis and characterization of PEG-b-(PG-g-PEI) for gene delivery].
abstract: OBJECTIVE
  To synthesize a biodegradable non-viral gene carrier with a high transfection efficiency and a low cytotoxicity.
  
  
  METHODS
  Poly(ethylene glycol)-block-(poly(L-glutamic acid)-graft-polyethylenimine) was prepared via ammonolysis of poly(ethylene glycol)-block-poly (γ-benzyl L-glutamate) with the low-molecular-mass polyethylenimine (600 Da). The synthesized copolymer was characterized by 1H nuclear magnetic resonance spectroscopy and gel permeation chromatography. The polyplex micelle from PEG-b-(PG-g-PEI) and plasmid DNA (pDNA) was studied using dynamic light scattering, zeta-potential measurements, and gel retardation assay. The in vitro cytotoxicity and transfection efficiency of PEG-b-(PG-g-PEI) were tested by MTT assay and luciferase assay in HEK 293T cells using PEI (25 kDa) as the control.
  
  
  RESULTS
  PEG-b-(PG-g-PEI) could efficiently condense DNA into nanosized particles with positive surface charges when the N/P ratio of polymer and DNA was above 5:1. The zeta potential of the polyplexes was about 25 mV, and the particle size was 120 nm at a N/P ratio of 10. The cell toxicity and gene transfection evaluations showed a lower cytotoxicity and a higher gene transfection efficiency of the copolymer than PEI 25000 in HEK 293T cells.
  
  
  CONCLUSIONS
  The polymer can be used as a potential non-viral gene carrier for gene therapy.
authors.affiliation: School of Pharmacy, Anhui University of Chinese Medicine, Hefei 230031, China.E-mail: hening826@163.com.
authors.forename: Ning
authors.initials: N
authors.lastname: He
authors.forename: Hechun
authors.initials: H
authors.lastname: Sun
authors.forename: Huanxi
authors.initials: H
authors.lastname: Xu
authors.forename: Xiaoman
authors.initials: X
authors.lastname: Dong
authors.forename: Zhangzhang
authors.initials: Z
authors.lastname: Shao
mesh_terms: D002470:Cell Survival; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D018698:Glutamic Acid / Q000737:chemistry; D057809:HEK293 Cells; D006801:Humans; D010316:Particle Size; D010957:Plasmids; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry*; D011094:Polyethyleneimine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D011108:Polymers; D014162:Transfection
chemical_list: C000604300:PEG-b-(PG-g-PEI); D011108:Polymers; C544016:poly(ethylene glycol)-co-poly(ethyleneimine); D011099:Polyglutamic Acid; D018698:Glutamic Acid; D011092:Polyethylene Glycols; D011094:Polyethyleneimine