title: [PEGylation of polyamidoamine dendrimer and the properties for gene vectors].
abstract: Polyamidoamine-polyethylene glycol (PAMAM-PEG) copolymers were synthesized using IPDI as coupling reagent by two-step method. The copolymers were characterized by IR spectrum and 1H NMR spectrum, and the PEG conjugating ratios of the copolymers were calculated equal to 10% and 30% separately. MTT assay indicated that after PEGylation a lower cytotoxicity of the copolymers could be found, and with increasing PEG conjugating ratio the cytotoxicity decreased obviously. Agarose gel retardation assay demonstrated that PAMAM-PEG copolymers could be combined with DNA and PAMAM-PEG/DNA complexes were prepared by self-assembly. DLS measurement showed that when N/P > or = 50, the particle size of copolymer/ gene complexes was in a range of 150-200 nm, and the zeta potential was in a range of 10-25 mV. In vitro gene transfection illustrated that when N/P < or = 50, the gene transfection efficiency of PAMAM-PEG copolymers was a little less than that of PAMAM-G5, but the transfection efficiency can be raised by increasing N/P ratio or transfection time. Considering both cytotoxicity and transfection efficiency aspects PAMAM-PEG-13 was more effect than PAMAM-PEG-39 in PEGylation.
authors.affiliation: The First Affiliated Hospital, Sun Yet-sen University, Guangzhou 510080, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Wang
authors.forename: Shi-Rong
authors.initials: SR
authors.lastname: Pan
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Wu
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Wen
authors.forename: Xin
authors.initials: X
authors.lastname: Zeng
authors.forename: Min
authors.initials: M
authors.lastname: Feng
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D004247:DNA / Q000737:chemistry* / Q000494:pharmacology; D050091:Dendrimers / Q000138:chemical synthesis* / Q000494:pharmacology; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006801:Humans; D017953:Isocyanates / Q000737:chemistry; D008113:Liver Neoplasms / Q000473:pathology; D010316:Particle Size; D011073:Polyamines / Q000737:chemistry; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D014162:Transfection
chemical_list: D050091:Dendrimers; D017953:Isocyanates; C522249:PEG-PAMAM; C531249:Poly(amidoamine); D011073:Polyamines; D011092:Polyethylene Glycols; C015301:isophorone diisocyanate; C028210:monomethoxypolyethylene glycol; D004247:DNA