Write your abstract here.
Carbon nanotubes show drug delivery promise.
14:43 16 December 2003
Carbon
nanotubes are adept at entering the nuclei of cells,
researchers have
discovered, and may one day be used to deliver drugs and vaccines.
The
modified nanotubes have so far only been used to ferry a small peptide
into the nuclei of fibroblast cells. But the researchers are hopeful
that the technique may one day form the basis for new anti-cancer
treatments, gene therapies and vaccines.
"Our
research is still in its earliest stages, but it shows great promise,"
says Alberto Bianco, at the CNRS Institute in Strasbourg, France. "The
nanotubes seem to migrate mainly to the nucleus, so we can imagine them
being used to deliver gene constructs."
"We can also imagine them being used to deliver drugs to specific compartments of the cell," he told New Scientist.
Rapid migration
Off-the-shelf
carbon nanotubes were used by Bianco''s team as the basis for their
''nano
delivery vehicle''. The tubes were modified by heating them for
several days in dimethylformamide, which enabled short linking chains
of triethyleneglycol (TEG) to be attached. Then, a small peptide was
bonded to the TEG molecule.
When
the modified nanotubes were mixed with cultures of human fibroblast
cells they rapidly entered and migrated towards the nucleus. At low
doses the nanotubes appeared to leave the cells unharmed, but as the
concentration increased cells began to die.
"The
nanotubes do not appear to be highly toxic," says Bianco. "But we do
now have to work out what happens to the nanotubes in the body."
Custom delivery
In
principle, a wide range of different molecules could be attached to the
nanotubes, raising the possibility of an easily customised way of
ferrying molecules into cells.
This has begun to excite other researchers. Ruth Duncan, who works on drug delivery mechanisms at Cardiff University, UK, told New Scientist:
"There''s a lot of evidence that other nanoparticles could be useful in
delivering drugs so this is a very interesting and exciting area. But I
am completely baffled about how the nanotubes manage to get into the
cells."
Duncan
says researchers have tried without much success to use buckyballs - a
spherical form of carbon nanotubes - as a way of ferrying anti-cancer
drugs and radionucleotides into cells.
Journal Reference: Chemical Communications (DOI: 10.1039/b311254c)