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Difference in the core-shell dynamics of polyethyleneimine and poly(l-lysine) DNA polyplexes

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
Pages (from-to)122-127
JournalEuropean Journal of Pharmaceutical Sciences
Early online date2017
Publication statusPublished - 2017
Publication typeA1 Journal article-refereed


Electrostatic polymer-DNA complexes (polyplexes) have been widely investigated for DNA delivery, and remarkable differences in transfection efficacy have been seen among the materials. For example, polyethyleneimine (PEI) mediates DNA transfection more effectively than poly(l-lysine) (PLL). Biophysical properties of the polyplexes may explain their different properties in gene delivery. We investigated the structural dynamics in DNA polyplexes, especially the material exchange between the core and shell regions of the PEI and PLL polyplexes. Steady-state fluorescence spectroscopy and double labeling based fluorescence resonance energy transfer (FRET) techniques were used to study the DNA polyplexes. According to our results there is a clear difference between these two polymers: core exchange takes place in PEI but not in PLL polyplexes. Such differences in structural dynamics of polyplexes explain, at least partly, the differences in DNA release and transfection efficacy at cellular level.

ASJC Scopus subject areas


  • DNA complexation, Fluorescence spectroscopy, Non-viral gene delivery, Poly-l-lysine, Polyethylene imine, Polyplex

Publication forum classification

Field of science, Statistics Finland