Document Detail


An acid sensitive ketal-based polyethylene glycol-oligoethylenimine copolymer mediates improved transfection efficiency at reduced toxicity.
MedLine Citation:
PMID:  18751876     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: Dynamic PEG-polycation copolymers that release PEG and degrade into small fragments after cell entry might present efficient and biocompatible gene carriers. METHODS: PEG-OEI-MK was synthesized by copolymerization of 5 kDa polyethyleneglycol (PEG) and 800 Da oligoethylenimines through acid-degradable acetone-bis-(N-maleimidoethyl)ketal linkers (MK). To evaluate any benefit of the reversible over stable linkage, also the corresponding pH-stable analog, PEG-OEI-BM, was synthesized via ether linkages. Luciferase and GFP expression plasmids were used for transfections, in vivo biocompatibility was evaluated by intravenous application of polymers in Balb/c mice. RESULTS: PEG-OEI-MK showed efficient DNA binding as analyzed by ethidium bromide exclusion, resulting in formation of polyplexes with sizes around 100 nm and surface charges of below 5 mV zeta potential. This surface shielding of PEG-OEI-MK polyplexes remained stable at neutral pH 7.4, while polyplexes deshielded and aggregated at pH 5 within 15-30 min. Cell culture experiments demonstrated reduced polymer toxicity compared to the non-PEGylated OEI-MK. Transfection experiments demonstrated reduced gene expression of PEG-OEI-BM compared with the non-PEGylated analog OEI-BM, whereas the pH-reversible polymer PEG-OEI-MK mediated a significant increased transfection efficiency over the non-PEGylated OEI-MK. CONCLUSIONS: PEG-OEI-MK mediated the highest gene transfer at lowest cytotoxicity levels and also best in vivo biocompatibility.
Authors:
Veronika Knorr; Manfred Ogris; Ernst Wagner
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-08-27
Journal Detail:
Title:  Pharmaceutical research     Volume:  25     ISSN:  0724-8741     ISO Abbreviation:  Pharm. Res.     Publication Date:  2008 Dec 
Date Detail:
Created Date:  2008-12-02     Completed Date:  2009-02-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8406521     Medline TA:  Pharm Res     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2937-45     Citation Subset:  IM    
Affiliation:
Pharmaceutical Biology-Biotechnology, Center for Drug Research and Center for NanoScience, Ludwig-Maximilians-Universität München, Munich, Germany.
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MeSH Terms
Descriptor/Qualifier:
Animals
Biocompatible Materials / chemistry
Female
Hydrogen-Ion Concentration
Mice
Mice, Inbred BALB C
Polyethylene Glycols / chemistry
Polyethyleneimine / chemistry
Polymers / chemical synthesis,  chemistry*,  toxicity
Transfection / methods*
Chemical
Reg. No./Substance:
0/Biocompatible Materials; 0/Polyethylene Glycols; 0/Polymers; 9002-98-6/Polyethyleneimine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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