By EurekAlert
Thursday, February 4, 2010
Using lasers and nanoparticles, scientists at Rice University
have discovered a new technique for singling out individual
diseased cells and destroying them with tiny explosions. The
scientists used lasers to make "nanobubbles" by zapping gold
nanoparticles inside cells. In tests on cancer cells, they found
they could tune the lasers to create either small, bright bubbles
that were visible but harmless or large bubbles that burst the
cells.
"Single-cell targeting is one of the most touted advantages of
nanomedicine, and our approach delivers on that promise with a
localized effect inside an individual cell," said Rice physicist
Dmitri Lapotko, the lead researcher on the project. "The idea is to
spot and treat unhealthy cells early, before a disease progresses
to the point of making people extremely ill."
The research is available online in the journal
Nanotechnology.
Nanobubbles are created when gold nanoparticles are struck by
short laser pulses. The short-lived bubbles are very bright and can
be made smaller or larger by varying the power of the laser.
Because they are visible under a microscope, nanobubbles can be
used to either diagnose sick cells or to track the explosions that
are destroying them.
In laboratory studies published last year, Lapotko and
colleagues at the Laboratory for Laser Cytotechnologies at the A.V.
Lykov Heat and Mass Transfer Institute in Minsk, Belarus, applied
nanobubbles to arterial plaque. They found that they could blast
right through the deposits that block arteries.
"The bubbles work like a jackhammer," Lapotko said.
In the current study, Lapotko and Rice colleague Jason Hafner,
associate professor of physics and astronomy and of chemistry,
tested the approach on leukemia cells and cells from head and neck
cancers. They attached antibodies to the nanoparticles so they
would target only the cancer cells, and they found the technique
was effective at locating and killing the cancer cells.
Lapotko said the nanobubble technology could be used for
"theranostics," a single process that combines diagnosis and
therapy. In addition, because the cell-bursting nanobubbles also
show up on microscopes in real time, Lapotko said the technique can
be use for post-therapeutic assessment, or what physicians often
refer to as "guidance."
Hafner said, "The mechanical and optical properties of the
bubbles offer unique advantages in localizing the biomedical
applications to the individual cell level, or perhaps even to work
within cells."
SOURCE