TY - JOUR

T1 - Revisit complexation between DNA and polyethylenimine — Effect of length of free polycationic chains on gene transfection

A1 - Yue,Yanan

A1 - Jin,Fan

A1 - Deng,Rui

A1 - Cai,Jinge

A1 - Dai,Zhuojun

A1 - Lin,Marie C.M.

A1 - Kung,Hsiang-Fu

A1 - Mattebjerg,Maria Ahlm

A1 - Andresen,Thomas Lars

A1 - Wu,Chi

AU - Yue,Yanan

AU - Jin,Fan

AU - Deng,Rui

AU - Cai,Jinge

AU - Dai,Zhuojun

AU - Lin,Marie C.M.

AU - Kung,Hsiang-Fu

AU - Mattebjerg,Maria Ahlm

AU - Andresen,Thomas Lars

AU - Wu,Chi

PB - Elsevier BV

PY - 2011

Y1 - 2011

N2 - Our revisit of the complexation between DNA and polyethylenimine (PEI) by using a combination of laser light scattering and gel electrophoresis confirms that nearly all the DNA chains are complexed with PEI to form polyplexes when the molar ratio of nitrogen from PEI to phosphate from DNA (N:P) reaches ~3, irrespective of the PEI chain length and solvent. Each solution mixture with N:P>3 contains two kinds of PEI chains: bound to DNA and free in the solution. It has been shown that it is those free PEI chains that play a vital role in promoting the gene transfection. The effects of the length of the bound and free chains on the gene transfection were respectively studied. Both short and long PEI chains are capable of condensing DNA completely at N:P~3 but long ones are ~102-fold more effective in the gene transfection, apparently due to their fast endocytosis and intracellular trafficking. The cellular uptake kinetics studied by flow cytometry reveals that long free chains increase the uptake rate constant of the DNA/PEI complexes. In the intracellular pathway, they are able to prevent the development of the later endolysosomes, and facilitate the subsequent release of the polyplexes from the endosomes. Our result shows that the “proton sponge” effect is not dominant because the shut-down of the proton pump only partially attenuates the transfection efficiency. A possible mechanism is speculated and presented.

AB - Our revisit of the complexation between DNA and polyethylenimine (PEI) by using a combination of laser light scattering and gel electrophoresis confirms that nearly all the DNA chains are complexed with PEI to form polyplexes when the molar ratio of nitrogen from PEI to phosphate from DNA (N:P) reaches ~3, irrespective of the PEI chain length and solvent. Each solution mixture with N:P>3 contains two kinds of PEI chains: bound to DNA and free in the solution. It has been shown that it is those free PEI chains that play a vital role in promoting the gene transfection. The effects of the length of the bound and free chains on the gene transfection were respectively studied. Both short and long PEI chains are capable of condensing DNA completely at N:P~3 but long ones are ~102-fold more effective in the gene transfection, apparently due to their fast endocytosis and intracellular trafficking. The cellular uptake kinetics studied by flow cytometry reveals that long free chains increase the uptake rate constant of the DNA/PEI complexes. In the intracellular pathway, they are able to prevent the development of the later endolysosomes, and facilitate the subsequent release of the polyplexes from the endosomes. Our result shows that the “proton sponge” effect is not dominant because the shut-down of the proton pump only partially attenuates the transfection efficiency. A possible mechanism is speculated and presented.

U2 - 10.1016/j.jconrel.2011.03.020

DO - 10.1016/j.jconrel.2011.03.020

JO - Journal of Controlled Release

JF - Journal of Controlled Release

SN - 0168-3659

IS - 1

VL - 152

SP - 143

EP - 151

ER -