Nanoneedles may help the
body repair
itself
Scientists
have developed tiny nanoneedles that have successfully
prompted
parts of the body to generate new blood vessels in a trial
in
mice, paving the way for new regenerative medicine
The
researchers, from Imperial College London and Houston Methodist
Research
Institute in the USA, hope their nanoneedle technique could
ultimately
help damaged organs and nerves to repair themselves and help
transplanted
organs to thrive.
The
nanoneedles work by delivering nucleic acids to a specific area.
Nucleic
acids are the building blocks of all living organisms and they
encode,
transmit and express genetic information. Scientists are currently
investigating
ways of using nucleic acids to re-program cells to carry out
different
functions.
The
nanoneedles are tiny porous structures that act as a sponge to load
significantly
more nucleic acids than solid structures. This makes them
more
effective at delivering their payload.They can penetrate the cell,
bypassing
its outer membrane, to deliver nucleic acids without harming
or
killing the cell. The nanoneedles are made from biodegradable silicon,
meaning
that they can be left in the body without leaving a toxic residue
behind.
The silicon degrades in about two days, leaving behind only a
negligible
amount of a harmless substance called orthosilicic acid.
In
a trial described in Nature Materials, the team showed they could
deliver
the nucleic acids DNA and siRNA into human cells in the lab,
using
the nanoneedles. They also showed they could deliver nucleic
acids
into the back muscles in mice. After seven days there was a
sixfold
increase in the formation of new blood vessels in the mouse
back
muscles, and blood vessels continued to form over a 14 day period.
The
technique did not cause inflammation or other harmful side effects.
The
hope is that one day scientists will be able to help promote the
generation
of new blood vessels in people, using nanoneedles, to provide
transplanted
organs or future artificial organ implants with the necessary
connections
to the rest of the body, so that they can function properly
with
a minimal chance of being rejected.
“This
is a quantum leap compared to existing technologies for the delivery
of
genetic material to cells and tissues,“ said Ennio Tasciotti, CoChair,
Department
of Nanomedicine at Houston Methodist Research Institute
and
co-corresponding author of the paper.
“By
gaining direct access to the cytoplasm of the cell we have achieved
genetic
reprogramming at an incredible high efficiency. This will let us
personalize
treatments for each patient, giving us endless possibilities in
sensing,
diagnosis and therapy. And all of this thanks to tiny structures
that
are up to 1,000 times smaller than a human hair.“
“It
is still very early days in our research, but we are pleased that the
nanoneedles
have been successful in this trial in mice. There are a number
of
hurdles to overcome and we haven't yet trialled the nanoneedles in
humans,
but we think they have enormous potential for helping the body
to
repair itself,“ said Molly Stevens, cocorresponding author from the
Departments
of Materials and of Bioengineering at Imperial College London.
The
researchers are now aiming to develop a material like a flexible bandage
that
can incorporate the nanoneedles. The idea is that this would be applied
to
different parts of the body, internally or externally, to deliver the nucleic
acids
necessary to repair and reset the cell programming.
“If
we can harness the power of nucleic acids and prompt them to carry out
specific tasks, it will give us a way to
regenerate lost function.Perhaps in
the
future it may be possible for doctors to apply flexible bandages to severely
burnt
skin to reprogram the cells to heal that injury with functional tissue
instead
of forming a scar. Alternatively, we may see surgeons first applying
the
nanoneedle bandages inside the affected region to promote the healthy
integration
of these new organs and implants in the body.
We
are a long way off, but our initial trials seem very promising,“ said
Ciro
Chiappini, first author of the study.
|
MM1APR15
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