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Updated: Jun 13, 2026

Preparation of Neutrally-charged, pH-responsive Polymeric Nanoparticles for Cytosolic siRNA Delivery
Published on: May 2, 2019
The effect of charge-reversal amphiphile spacer composition on DNA and siRNA delivery
Xiao-Xiang Zhang1, Carla A H Prata, Thomas J McIntosh
1Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA.
Abstract:
A series of charge-reversal amphiphiles with different spacers separating the headgroup from the hydrophobic chains are described for delivery of DNA and siRNA. Among them, the amphiphiles possessing a glycine spacer (e.g., B-GlyGly) showed effective DNA transfection in CHO and NIH 3T3 cells, as well as siRNA gene knockdown in HepG2 and UASMC cells. Ethidium bromide quenching assays revealed that DNA was released the fastest from the lipoplex of B-GlyGly in the presence of esterase. Also, X-ray diffraction results indicated that the DNA was located between the adjacent lipid bilayers in the lipoplex of B-GlyGly. These distinct features appear to be required for high transfection activity.
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