title: [Impact of polyamidoamine dendrimer liposome on the cellular uptake and cytotoxicity of colonic cancer cells].
abstract: OBJECTIVE
  To evaluate the effects of polyamidoamine dendrimer (PAMAM) liposome as gene carriers on the cellular uptake and its cytotoxicity in colonic cancer cell.
  
  
  METHODS
  The liposome modified PAMAM was synthesized with liposome and polyamidoamine dendrimer. Plasmid PEGFP-N1 was mixed with the liposome-modified PAMAM or unmodified PAMAM to form nanoparticle complexes. The shape and size of the nanoparticle complexes were observed by transmission electron microscope and the zeta potential was measured by analytical tool. The encapsulating efficiency was determined by ultraviolet spectrophotometer in centrifuging method. After the cell lines SW620 (colonic cancer cell), MCF-7 (breast cancer cell), ECV304 (vascular endothelial cell) were transfected by the two kinds of PAMAM nanoparticle complexes, the flow cytometry was used to determine the uptake of enhanced green fluorescent protein (EGFP) gene. The cytotoxicity of PAMAM liposome nanoparticles and PAMAM nanoparticles was evaluated by MTT assay.
  
  
  RESULTS
  The diameter of liposome modified PAMAM complex was (192 ± 16) nm, and that of PAMAM complex was (189 ± 19) nm (P > 0.05); and the zeta potential of liposome modified PAMAM complex was higher than that of PAMAM complex [(42 ± 7) mV vs. (32 ± 7) mV, P < 0.05]. There was no significant difference in envelopment rate between the two groups [(82 ± 7)% vs. (84 ± 6)%, P > 0.05]. After the colonic cancer cell line SW620 was transfected with the two kinds of PAMAM nanoparticle complexes, the cellular uptake of the cells with the liposome-modified PAMAM complex was significantly higher than that of the cell with PAMAM complex (P < 0.05). The cellular survival rate of the cell lines with liposome-modified PAMAM complex was significantly higher than that of cell lines with PAMAM complex (P < 0.05).
  
  
  CONCLUSIONS
  The liposome modified PAMAM can improve gene transfection efficiency and suppress its cytotoxicity.
authors.affiliation: National Medical Center of Anorectal Surgery, the Third Affiliated Hospital, Nanjing University of Traditional Chinese Medicine, Nanjing 210001, China. yaohang84@yahoo.com.cn
authors.forename: Hang
authors.initials: H
authors.lastname: Yao
authors.forename: Hei-Ying
authors.initials: HY
authors.lastname: Jin
authors.forename: Kun-Lan
authors.initials: KL
authors.lastname: Wu
authors.forename: Jin-Hao
authors.initials: JH
authors.lastname: Zhang
authors.forename: Pei
authors.initials: P
authors.lastname: Zhang
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Wang
authors.forename: Da-Xiang
authors.initials: DX
authors.lastname: Cui
authors.forename: Yi-Jiang
authors.initials: YJ
authors.lastname: Ding
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology*; D050091:Dendrimers / Q000493:pharmacokinetics / Q000633:toxicity*; D005822:Genetic Vectors / Q000493:pharmacokinetics / Q000633:toxicity; D006801:Humans; D008081:Liposomes / Q000493:pharmacokinetics / Q000633:toxicity*; D014162:Transfection
chemical_list: D050091:Dendrimers; D008081:Liposomes