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Dendritic Polyamines: Simple Access to New Materials with Defined Treelike Structures for Application in Nonviral Gene Delivery
Author(s) -
Krämer Michael,
Stumbé JeanFrançois,
Grimm Günther,
Kaufmann Brigitte,
Krüger Ute,
Weber Martin,
Haag Rainer
Publication year - 2004
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.200300905
Subject(s) - polyethylenimine , dendrimer , transfection , gene delivery , branching (polymer chemistry) , polymer , surface modification , cytotoxicity , chemistry , in vitro , dna , biophysics , amidoamine , materials science , combinatorial chemistry , polymer chemistry , biochemistry , organic chemistry , gene , biology
Polycationic dendrimers are interesting nonviral vectors for in vitro DNA delivery. We describe a simple approach to the synthesis of dendritic polyamines with different molecular weights and adjustable flexibility (degrees of branching; DB). Both parameters influence the transfection efficiency and the cell toxicity of the polymer. Functionalization of hyperbranched polyethylenimine (PEI) by a two‐step procedure generated fully branched pseudodendrimers (analogues of polypropylenimine (PPI) and polyamidoamine (PAMAM) dendrimers). The DNA transfection efficiencies observed for these polymers depended on the cell line investigated. The highest efficiencies were observed for polymers whose unfunctionalized PEI cores had molecular weights in the range M w =6000–25 000 g mol −1 . The cytotoxicity of the dendrimers generally rises with increasing core size. The data collected for NIH/3T3 and COS‐7 cells indicate a maximum transfection efficiency at around 60 % branching for the PPI analogues, and at a PEI‐core molecular weight of M w =25 000 g mol −1 . PAMAM functionalization of PEI (M w =5000 and 21 000 g mol −1 ) leads to polymers with little or no cytotoxity in the cell lines investigated.