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Published on: May 6, 2010
Release of DNA binary complexes from the ternary complexes by carboxymethyl poly(L-histidine)
Shoichiro Asayama1, Miyuki Sudo, Hiroyoshi Kawakami
1Department of Applied Chemistry, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan. asayama-shoichiro@c.metro-u.ac.jp
Nucleic Acids Symposium Series (2004)
|September 15, 2009
Summary
Carboxymethyl poly(L-histidine) (CM-PLH) and poly(ethylenimine) (PEI) ternary complexes release DNA at endosomal pH. This DNA release mechanism enhances gene transfection activity.
Area of Science:
- Biochemistry
- Molecular Biology
- Gene Delivery Systems
Background:
- Gene delivery vectors are crucial for therapeutic applications.
- Poly(ethylenimine) (PEI) is a common non-viral gene vector.
- Modifications to PEI can improve its efficiency and safety.
Purpose of the Study:
- To investigate the dissociation mechanism of DNA from ternary complexes.
- To evaluate the role of carboxymethyl poly(L-histidine) (CM-PLH) in DNA release.
- To correlate DNA release with transfection activity.
Main Methods:
- Formation and characterization of CM-PLH/PEI/DNA ternary complexes.
- Fluorescence Resonance Energy Transfer (FRET) analysis to monitor CM-PLH and PEI dissociation.
- Competitive exchange assays using dextran sulfate to assess DNA release kinetics.
Main Results:
- CM-PLH protonation at endosomal/lysosomal pH triggers dissociation from PEI.
- FRET confirmed the dissociation of CM-PLH from the ternary complex.
- PEI/DNA binary complexes showed enhanced DNA release compared to ternary complexes.
Conclusions:
- The pH-dependent dissociation of CM-PLH is a key mechanism for DNA release.
- This controlled DNA release from PEI/DNA complexes enhances transfection efficiency.
- CM-PLH/PEI/DNA ternary complexes represent a promising strategy for gene delivery.
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