title: The influence of cyclodextrin modification on cellular uptake and transfection efficiency of polyplexes.
abstract: Cyclodextrin-modified polycations have been studied widely due to their low cytotoxicity, low immunogenicity and the ability to form inclusion complexes. However, the influence of CD modification on cellular uptake and transfection efficiency of polyplexes is still unclear. In this research, cyclodextrin-modified polyethylenimines (PEI-CD) with different CD-grafting levels were synthesized, which were named PEI-CD(15) and PEI-CD(41), respectively, according to the CD number per PEI chain. CD modification showed great influence on the DNA condensation ability of the polycation. PEI-CD(15) could protect DNA completely above N/P ratio of 2. The particle sizes of these polyplexes were about 120 nm. However, PEI-CD(41) could not protect DNA below N/P of 6, and PEI-CD(41)/DNA polyplexes were larger than 1 μm, even at N/P ratio of 10. Therefore, this research was mainly focused on PEI-CD(15). It was interesting that the PEI-CD(15)/DNA polyplexes at N/P ratio of 8 and 10 displayed excellent stability in physiological salt conditions, probably due to the hydration shell of CDs. The influence of CD modification on the cellular uptake and transfection efficiency of polyplexes depended on the type of the cells. Uptake inhibition experiments indicated that PEI/DNA polyplexes were internalized by HEK293T cells by both clathrin-mediated endocytosis and caveolae-mediated endocytosis. The route of caveolae-mediated endocytosis was significantly promoted after CD modification. So the cell uptake and transfection efficiency of PEI-CD(15)/DNA polyplexes were significantly improved for HEK293T cells. However, the uptake and transfection efficiency of PEI-CD(15)/DNA polyplexes in HepG2 cells was similar to that of PEI/DNA polyplexes, probably due to the lack of endogenous caveolins.
authors.affiliation: MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China.
authors.forename: Wenyu
authors.initials: W
authors.lastname: Li
authors.forename: Lina
authors.initials: L
authors.lastname: Chen
authors.forename: Zhixiong
authors.initials: Z
authors.lastname: Huang
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Wu
authors.forename: Yuanfeng
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qiaoling
authors.initials: Q
authors.lastname: Hu
authors.forename: Youxiang
authors.initials: Y
authors.lastname: Wang
mesh_terms: D021941:Caveolae / Q000378:metabolism; D002966:Clathrin / Q000378:metabolism; D003505:Cyclodextrins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D004247:DNA / Q000737:chemistry*; D004705:Endocytosis / Q000187:drug effects; D005434:Flow Cytometry; D018014:Gene Transfer Techniques; D057809:HEK293 Cells; D056945:Hep G2 Cells; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D009690:Nucleic Acid Conformation / Q000187:drug effects*; D009928:Organ Specificity; D010316:Particle Size; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D011073:Polyamines / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D000071228:Polyelectrolytes; D011094:Polyethyleneimine / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D002966:Clathrin; D003505:Cyclodextrins; D004247:DNA; D011073:Polyamines; D000071228:Polyelectrolytes; D011094:Polyethyleneimine