Washington: In a major step towards gene
therapy, scientists claim to have designed a new device -- a
nanoparticle -- which can effectively deliver genes into cells
with minimal toxic effects.
In laboratory experiments, a team at Ohio State
University has found that this device, a vector, is able to
deliver DNA deeply enough into cell to allow genetic material
to be activated -- a critical step in gene therapy.
This vector is between two-and-a-half and 10 times
more effective than other experimental materials, according to
In fact, in their research, the scientists combined
two ingredients -- calcium phosphate and a lipid shell -- to
create a nanoparticle that protects DNA during its journey to
the cell and then dissolves to allow for gene activation in
the target cell.
Nano refers to the tiny size of the particle in
question -- its general structure can be detected only by an
atomic force microscope.
Calcium phosphate is a mineral found in bones and
teeth. Lipids are fatty molecules that help maintain the
structure of cell membranes. Together, they form a protective
and inflexible structure that, thanks to complex chemical
reactions, self-destructs once inside a cell.
"What we do is encapsulate a calcium phosphate core
inside the liposome. And when this calcium phosphate gets
inside a cell and that environment becomes acidic, it gets
dissolved and then the gene can be very effectively released
into the cytoplasm and transported to the nucleus. That is the
theory," said lead scientist Chenguang Zhou.
He added: "Our nanoparticle is a foreign body
just like a viral vector is, but it has a self-destructive
mechanism so it does not generate a strong response from the
"The material we use is also biocompatible. Calcium
phosphate is in our bones and the lipids we use are synthetic,
but can be biologically degraded. That`s why there is low
The findings have been published in the `International
Journal of Pharmaceutics`.