posted on 2013-05-06, 00:00authored byRahul K. Keswani, Ian M. Pozdol, Daniel W. Pack
Recombinant retroviruses provide
highly efficient gene delivery and the potential for stable gene expression.
The retroviral envelope protein, however, is the source of significant
disadvantages such as immunogenicity, poor stability (half-life of
transduction activity of 5–7 h at 37 °C for amphotropic
murine leukemia virus), and difficult production and purification.
To address these problems, we report the construction of efficient
hybrid vectors through the association of murine leukemia virus (MLV)-like
particles (M-VLP) with synthetic liposomes comprising DOTAP, DOPE,
and cholesterol (φ/M-VLP). We conclude that the lipid composition
is a significant determinant of the transfection efficiency and uptake
of φ/M-VLP in HEK293 cells with favorable compositions for transfections
being those with low DOTAP, low DOPE, and high cholesterol content.
Cellular uptake, however, was dependent on DOTAP content alone. By
extrusion of liposomes prior to vector assembly, the size of these
hybrid vectors could also be decreased to ≈300 nm, as confirmed
via DLS and TEM. φ/M-VLP were also robust on storage in terms
of vector size and transfection efficiency and provided stable transgene
expression over a period of three weeks. We conclude that the noncovalent
combination of biocompatible synthetic lipids with inactive retroviral
particles to form a highly efficient hybrid vector is a significant
extension to the development of novel gene delivery platforms.