Marcos Dantus, chemistry department |
To
test for skin cancer, patients today must endure doctors cutting away a
sliver of skin, sending the biopsy to a lab and anxiously awaiting the
results. Using laser microscopes that deploy rapid, ultra-short pulses
to identify molecules, doctors may soon have the tools to painlessly
scan a patient’s troublesome mole and review the results on the spot,
said Marcos Dantus.
The
results touting this new molecule-selective technology can be found in
the current issue of Nature Photonics, which Dantus co-authored with
Sunney Xie of Harvard University.
“Smart
lasers allow us to selectively excite compounds – even ones with small
spectroscopic differences,” said Dantus. “We can shape the pulse of the
lasers, excite one compound or another based on their vibrational
signatures, and this gives us excellent contrast.”
In
the past, researchers could approach this level of contrast by
introducing fluorescent compounds. With the breakthrough using
stimulated Raman scattering microscopy, fluorescent markers are
unnecessary.
“Label-free
molecular imaging has been the holy grail in medicine,” Dantus said.
“SRS imaging gives greater specificity and the ability to map a
particular chemical species in the presence of an interfering species,
such as cholesterol in the presence of lipids.”
Additional
potential applications include allowing researchers to closely examine
how compounds penetrate skin and hair. Smart lasers also can better
identify how drugs penetrate tissue and how drugs and tissue interact,
thus mitigating the chances of potential side effects and helping reduce
the time required to bring new drugs to market.
Dantus also is using smart laser imaging technology at MSU for detecting traces of hazardous substances from a distance.
“The
ability to image with molecular specificity and sensitivity opens a
number of applications in medicine as well as in homeland security,” he
said.
Collaboration
for the paper began when Harvard graduate student Christian Freudiger
contacted BioPhotonic Solutions, a high-tech company Dantus launched in
2003 based on his research at MSU. Dantus was not only able to provide
the laser pulse shaper Harvard needed to conduct the research, but he
also was able to lend his expertise as well as the support of his MSU
laboratory, Dantus said.
“I
like to say that we enable technology,” he said. “Controlling
ultrashort pulses, which once required Ph.D. experts, can now be done
with push-button simplicity by a small computer-controlled box. This
instrument is now being used in the most prestigious research
laboratories in the world.”
Dantus’ research is funded in part by the National Science Foundation.