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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2008-7-16
pubmed:abstractText
Polymer carriers like PEI which proved their efficiency in DNA delivery were found to be far less effective for the applications with siRNA. In the current study, we generated a number of nontoxic derivates of branched PEI through modification of amines by ethyl acrylate, acetylation of primary amines, or introduction of negatively charged propionic acid or succinic acid groups to the polymer structure. The resulting products showed high efficiency in siRNA-mediated knockdown of target gene. In particular, succinylation of branched PEI resulted in up to 10-fold lower polymer toxicity in comparison to unmodified PEI. Formulations of siRNA with succinylated PEI were able to induce remarkable knockdown (80% relative to untreated cells) of target luciferase gene at the lowest tested siRNA concentration of 50 nM in Neuro2ALuc cells. The polyplex stability assay revealed that the efficiency of formulations which are stable in physiological saline is independent of the affinity of siRNA to the polymer chain. The improved properties of modified PEI as siRNA carrier are largely a consequence of the lower polymer toxicity. In order to achieve significant knockdown of target gene, the PEI-based polymer has to be applied at higher concentrations, required most probably for sufficient accumulation and proton sponge effects in endosomes. Unmodified PEI is highly toxic at such polymer concentrations. In contrast, the far less toxic modified analogues can be applied in concentrations required for the knockdown of target genes without side effects.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1520-4812
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1448-55
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Simple modifications of branched PEI lead to highly efficient siRNA carriers with low toxicity.
pubmed:affiliation
Center for Drug Research, Department of Pharmacy, and Center for NanoScience (CeNS), Ludwig-Maximilians-University, Butenandstr. 5-13, D-81377 Munich, Germany. arkadi.zintchenko@cup.uni-muenchen.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't