Format

Send to

Choose Destination
Biomaterials. 2014 Jun;35(18):4996-5005. doi: 10.1016/j.biomaterials.2014.03.007. Epub 2014 Mar 21.

Uptake and transfection efficiency of PEGylated cationic liposome-DNA complexes with and without RGD-tagging.

Author information

1
Department of Physics, University of California, Santa Barbara, CA 93106, USA; Department of Materials, University of California, Santa Barbara, CA 93106, USA; Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106, USA.
2
Department of Physics, University of California, Santa Barbara, CA 93106, USA; Department of Materials, University of California, Santa Barbara, CA 93106, USA; Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106, USA; Institute of Physics, Academica Sinica, Taipei 11529, Taiwan; National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
3
Department of Physics, University of California, Santa Barbara, CA 93106, USA; Department of Materials, University of California, Santa Barbara, CA 93106, USA; Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106, USA; Division of Physical Chemistry, Centre for Chemistry and Chemical Engineering, Lund University, SE-221 00 Lund, Sweden.
4
National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan; Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
5
National Resource for Automated Molecular Microscopy, Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
6
Department of Physics, University of California, Santa Barbara, CA 93106, USA; Department of Materials, University of California, Santa Barbara, CA 93106, USA; Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA 93106, USA. Electronic address: safinya@mrl.ucsb.edu.

Abstract

Steric stabilization of cationic liposome-DNA (CL-DNA) complexes is required for in vivo applications such as gene therapy. PEGylation (PEG: poly(ethylene glycol)) of CL-DNA complexes by addition of PEG2000-lipids yields sterically stabilized nanoparticles but strongly reduces their gene delivery efficacy. PEGylation-induced weakening of the electrostatic binding of CL-DNA nanoparticles to cells (leading to reduced uptake) has been considered as a possible cause, but experimental results have been ambiguous. Using quantitative live-cell imaging in vitro, we have investigated cell attachment and uptake of PEGylated CL-DNA nanoparticles with and without a custom synthesized RGD-peptide grafted to the distal ends of PEG2000-lipids. The RGD-tagged nanoparticles exhibit strongly increased cellular attachment as well as uptake compared to nanoparticles without grafted peptide. Transfection efficiency of RGD-tagged PEGylated CL-DNA NPs increases by about an order of magnitude between NPs with low and high membrane charge density (σM; the average charge per unit area of the membrane; controlled by the molar ratio of cationic to neutral lipid), even though imaging data show that uptake of RGD-tagged particles is only slightly enhanced by high σM. This suggests that endosomal escape and, as a result, transfection efficiency of RGD-tagged NPs is facilitated by high σM. We present a model describing the interactions between PEGylated CL-DNA nanoparticles and the anionic cell membrane which shows how the PEG grafting density and membrane charge density affect adhesion of nanoparticles to the cell surface.

KEYWORDS:

Gene therapy; Liposome; Live cell imaging; Nanoparticle; Polyethylene glycol; RGD peptide

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center