VIENNA, Austria — Florence Gazeau is everything you would expect in a French researcher studying structural mobility for the National Center of Scientific Research (CNRS) at the Laboratoire Matière et Systèmes Complexe with the Université Paris-Diderot.
An unassuming and serious person, nothing about her suggests revolution.
In fact just reading the topic of her abstract, delivered at the European Congress of Radiology here last week, "Labeling and manipulating the cell with ultra-small super paramagnetic particles of iron oxide," might lull you to sleep.
Yet fellow researchers leaned forward in their seats during a parade of slides displaying images from a microscope showing cells loaded with magnetically sensitive particles that were first arranged in rows inside of cells using magnetic force, and then pulled from healthy tissue to a tumor in a mouse.
At this point, Gazeau suggested the first hint of a revolution shaping up in molecular biology that would shake fundamental ideas of medical devices and surgery.
"These cells can be considered as living robots, not only to image but to be manipulated and deliver therapies such as heat and the reconstruction of tissue," she said.
Today we understand the medical discipline to see-and-treat has shifted from the traumatically invasive cutting of open surgery to minimally invasive closed surgeries using sheaths and tubes, lighting and cameras and miniaturized knives or graspers.
What if at some point in your lifetime even today's most advanced micro tools used for procedures described as "willful violence upon the body," were to be replaced by a simple syringe, a magnet smaller than one on your refrigerator door and a humming magnetic resonance imaging (MRI) machine?
One day earlier, during the opening keynote presentation, Hedvig Hricak, chair of the department of radiology at Memorial Sloan-Kettering Cancer Center (New York) and chair of the board for the Radiological Society of North America (Oak Brook, Illinois) called for "targeted imaging for targeted therapies" (Medical Device Daily, March 10, 2009).
Hricak noted that disease-specific imaging linked to direct intervention are converging at the molecular level in the field of oncology.
Using images from a study of progressive prostate cancer that is still enrolling patients at Memorial Sloan-Kettering, she showed a standard computed tomography (CT) scan of a patient's pelvis indicating a few lesions.
For the same patient using a radioactive coated sugar, 18F-fluoro-2-desoxy-glucose, and positron emission tomography (18FDG-PET), the image showed a greater number of lesions for the same patient at the same site.
Finally, using the tracer [18F] fluoro-dihydro-testosterone (18F FDHT), which attaches to androgen receptors, PET imaging revealed the full extent of the spread of the cancer.
"And the best is yet to come, imaging a cell," Hricak said, adding that it is an advance that radiologists would not have imagined five years ago.
In a scientific session the following day at ECR 2009, Gazeau showed exactly that potential, and to the growing amazement of her colleagues, took them further than imaging to show non-interventional, yet mechanically induced therapies.
Particles measuring from 5 nanometers to 20 nanometers can be considered as a disease tracer actively seeking out specific cells, she said, and at the same time serve as a contrast agent to observe the disease process or monitor the forced migration of these cells with externally, or endoscopically, delivered magnetic force.
Their magnetic properties also mean electromagnetic force can be used to excite these nano particles in the cells and convert energy into heat causing the agents that targeted a tumor to serve as a thermally active therapy.
"I will not discuss this aspect today," she said, focusing her presentation at ECR focused on monitoring, targeting and delivering pharmo-biologic therapy.
Sorry folks, just a teaser.
"Iron oxide is a particle of a tunable size," she said showing a test tube with iron oxide particles in liquid state stuck against a magnet with the liquid suspended in a lump against the side of the tube like a refrigerator magnet.
They can be constructed to work with, or against, the body's natural processes, she said, to help determine where they will go.
Big particles, for example can be trapped within an organ such as the liver, or be small enough that the body allows them to circulate with blood.
Surface coatings for these nano particles are extremely important in this emerging field and determine the uptake by the patient's cells.
Tinkering with ligand coatings can result in low or medium or high uptake of anionic iron oxide particles by a tumoral cell.
High labeling efficiency, or coatings, can result in a predictable iron load in a cell and once taken into the cell, the particle is contained within the cell.
This leads to what Gazeau called "the best part."
Cell proliferation is not affected as it turns out anionic iron oxide particles are biocompatible and do not provoke exocytosis, or excretion of the particles by the cell as a waste product.
There is, however, a long-term degradation of the particles.
The benefit of these properties is that nano particles carrying payloads can be integrated into cells that continue to divide and proliferate naturally, and the particle can add or direct processes, such as muscle regeneration.
"Sorting cells in micro canals can be interesting, too," she hinted.
"The question we asked," Gazeau said, "is whether these properties can be used for tissue engineering."
A group in Japan has created an artificial vessel, she reports, asking then if this it be done in vivo.
Gazeau notes a research group in the United States recently conducted in vivo experiments to reconstruct tissue with a magnetic steel stent loading endothelial cells with magnetic nanoparticles.
In the brain, magnetic nanoparticles were accumulated at a point where they were held to affect microcirculation of blood, a proof of concept for micro targeting in vivo, she said.
There is a lot of work yet to do, Gazeau concluded, packing up to head back to the lab.