to the future
David F. Salisbury
Oct. 9, 2001
application of light to illuminate and manipulate the hidden worlds
of living organismsis the future direction that Vanderbilt's
free-electron laser center is taking.
envision ourselves as taking a leading role in exploring and applying
new knowledge about the interactions of photons and biomaterials,"
says center director David Piston.
Building on existing programs, including the FEL surgery, development
of the monochromatic X-ray and use of the FEL for protein identification,
this represents an ambitious expansion of the range of the center's
recently the center has been a one-horse operation, almost entirely
centered on the free-electron laser. But the successful development
of the monochromatic X-ray machine will soon add a second novel
light source to its research repertoire. In the future, Piston would
like to add at least two more new light sources.
FEL was originally designed and constructed with funding from the
Department of Defense as part of the Strategic Defense Initiative
and the DOD has continued to provide the lion's share of funding.
In fiscal year 2001/2002, for example, it is providing $2.5 million
out of the total $3 million in the center's external funding. The
National Cancer Institute is contributing $400,000 and the remainder
comes from three additional research grants from the National Institutes
support from the Department of Defense is solid, and will continue
to play a major role in the center's operation," says Piston,
"but we have set a high priority on diversifying our funding
is concentrating on four major research areas:
science. Center researchers have considerable expertise in
thin films, organic materials, nanocrystals, magnetic materials
and glasses. One of their current projects is the development
of a new kind of microscope that uses the infrared light from
the free-electron laser. Developed in collaboration with researchers
from the University of Rome and the Naval Research Laboratory
in Washington, DC, the scanning near-field optical microscope
(NSOM) can achieve a spatial resolution of a few hundred nanometers
with wavelengths in the one to seven micron range. This capability
could have a major impact on materials and biophotonics research.
The scientists have begun applying this technique to applications
ranging from mapping the electronic structure of semiconductors
near surfaces and interfaces to the examination of chemical components
in biological cells.
surgery. For ten years, center scientists have built up an
extensive base of knowledge of the way that the unique FEL beam
interacts with human tissue and have identified the specific wavelengths
that can cut soft tissue and bone with a minimum amount of damage
to adjacent areas. In the last two years, this knowledge has been
applied to a series of surgeries with human patients that have
been completely successful. In fact, the biggest surprise has
been that the operations went exactly as expected. So far, operations
have been done exclusively by Vanderbilt surgeons. In the future,
medical researchers from Duke and Stanford will also be participating.
The center is also supporting research to develop smaller and
less expensive solid-state lasers that can duplicate the characteristics
that make the FEL beam such an effective light scalpel.
Determining the function of the myriad of proteins that play essential
roles in living systems is vital to applying the knowledge gained
from the mapping of the human genome to finding new ways to treat
and prevent disease. Using the FEL beam to simplify and speed
up the method currently being used to identify proteins appears
likely to play an important role in this rapidly emerging field.
This technique, called IR-MALDI, has the potential for identifying
proteins in very small samples, and might even allow the analysis
of the proteins in single cells.
the monochromatic X-ray has the capability for drastically reducing
the time and the difficulty involved in determining protein structures
through X-ray crystallography. This is the premier method for
determining the structures of complex biomolecules, but can only
be done at a handful of synchrotron laboratories associated with
major particle accelerators. The center plans to construct a second
monochromatic X-ray device for this purpose.
- In Vivo
Imaging. Imagine being able to watch the movement of a single
molecule inside the body of a living animal! The center is using
a number of novel techniques, to achieve this goal. One approach
is to use mice that have been genetically engineered to produce
special proteins that fluoresce when illuminated with laser light
and then to insert optical fibers into the mouse's body to excite
these molecules and trace their motion.
Another is to use the monochromatic X-ray to produce three-dimensional
images of internal organs with an unprecedented level of detail.
Such a capability should shed important new information about
diseases such as cancer and diabetes.
In the 1960's,
lasers were characterized as a technology in search of an application.
Today, they are everywhere. Their remarkable success demonstrates
just how important new light sources can be, both as a research
tools and as components in new technologies. Both the FEL and the
monochromatic X-ray have unique characteristics that virtually guarantee
that they will be the source of valuable new information about living
systems and will provide the basis for important new technologies
in years to come.
article on In Vivo Imaging Center