By: Cynthia Macdonald
3 Sep, 2019
An amazing new instrument provides scar-free surgery and promises dramatic advances in wound healing and biodiagnostics for surgical guidance
R.J. Dwayne Miller works — quite literally — on the cutting edge of scientific innovation.
At the Max Planck Institute in Hamburg, Germany, the renowned physical chemist and CIFAR Fellow heads up a team that is perfecting an extraordinary surgical laser. While scarring is usually considered an inevitable byproduct of surgery, this instrument may well eliminate scars entirely.
The fibre beam delivery system is as thin as a human hair and can be robotically operated. Known as the PIRL (for Picosecond Infrared Laser) scalpel, it also holds enormous potential for ultrafast cancer biopsies, since it can provide an instant snapshot of the molecular signatures of the tissue being excised.
Even more amazing is that the PIRL may eventually allow surgeons to operate on only one cell at a time. Surgeons normally rely on tactile feedback, and their field of view is decidedly limited. The PIRL technique could furnish them with the precise molecular information needed to root out a malignant tumour’s foundational stem cells, leading to vastly increased survival rates. “Ever since the laser was invented in the 1960s, people have been saying we’d never get to the one-cell limit without collateral damage,” says Miller, a professor at the University of Toronto (U of T) and co-director of CIFAR’s Molecular Architecture of Life program. “It’s never happened – until now.”
Understanding the workings of a single cell – being able to see inside it and manipulate its processes – is what lies at the heart of this unique CIFAR program. Until recently, scientists saw cells as static pictures; a great deal about how they behaved could only be inferred. Thanks in great part to Miller and his Molecular Architecture of Life colleagues, all of that is now changing.
The story of the PIRL laser originated in 1989 when Dwayne Miller wondered: what would it be like to see atoms in motion?
After more than a decade of technological development, he and a team at U of T were finally able to do just that. They created history’s first “molecular movie”, resolving atomic motions during structural changes. By using light energy to excite atoms into motion, then hitting them with an electron flash lasting one quadrillionth of a second, “we hit that magical moment where we were literally watching atoms move in real time,” he says.
This discovery would ultimately have implications for laser surgery, since it helped Miller to understand phase transition – the process by which solids, liquids and gases change from one state of matter into another – much more clearly.
In traditional laser surgery, materials are cut via a form of induced phase transition known as ablation. From a molecular viewpoint, however, ablation can be a violent process, damaging solid tissue as it transitions into a gas phase. Consequently, though widely used in eye surgery, lasers have had fairly limited surgical applications.
“We’re closing in on how cell differentiation works — how one cell with the same DNA as another changes into a completely different cell type. Understanding cell phenotypes is one of the great mysteries of life.”
With newfound knowledge, Miller was able to devise an ingenious method of bypassing such damage, by selectively laser-exciting water molecules inside human tissue. “The PIRL scalpel injects molecules into the gas phase so fast that there is no time for molecular fragmentation,” he says. For his work, he was awarded the 2018 European Physical Society Award in Laser Science and Applications.
Right now, the PIRL’s effectiveness in scar-free laser eye surgery will imminently be tested in clinical trials; with proper funding, Miller hopes that its other possible uses (such as imaging cancer margins for secure removal and biopsies) can also be tested in the near future. In the meantime, other fellows in CIFAR’s Molecular Architecture of Life program are also exploring and manipulating the fundamental properties of cells (using modern techniques such as mass spectrometry, molecular MRI’s, time-resolved optical microscopy and cryo-electron microscopy) to develop a complete picture of cell functions.
“We’re closing in on how cell differentiation works — how one cell with the same DNA as another changes into a completely different cell type,” Miller says. “Understanding cell phenotypes is one of the great mysteries of life. Using the PIRL concept to literally do surgery inside the cell, we hope to answer how a cell’s chemistry works to execute the biochemical program we call life, and give rise to cellular functions.”
CIFAR’s research programs address important questions facing science & humanity across four interdisciplinary theme areas: Life & Health, Individuals & Society, Information & Matter and Earth & Space.
CIFAR is a registered charitable organization supported by the governments of Canada, Alberta and Quebec, as well as foundations, individuals, corporations and Canadian and international partner organizations.