Nanopharmaceuticals, a discipline that has emerged from nanotechnology, which means extreme miniaturization of a process or technique (one nanometre = one millionth of a metre), focuses on drugs of infinitesimal dimensions. It is the field of research of chemist Françoise Winnik, who directs the Laboratory of Soft Materials and Nanopharmaceuticals, created in 2000 at Université de Montréal.

One of the few women specializing in nanotechnology in Quebec, Prof. Winnik is especially interested in how nanometric particles, the coatings of drugs that are made of soft materials, are transported. "These materials are polymers with almost miraculous properties," she says. The therapeutic agents are covered with them so that they can travel through the body to a target, such as a cancerous tumour, where they release their chemicals."

Her fascination with these polymers goes back to the early 1990s, when a worldwide interest had emerged for a type of polymers, poly-N-isopropylacrylamide, more commonly called pnipam, which is soluble in cold water but not in hot water. This polymer will open or close in response to changes of water temperature, with a breaking point around 31° C. The very prototype of the "intelligent" polymer, it has tremendous potential in one aqueous environment in particular: the human body.

"To penetrate to a target, you build the polymer in a special way, which means that you "decorate" it, for example by implanting oily substances on it," the chemist explains. These fats become motors of agglomerates and, by natural attractions, provoke the transformation of the long polymer molecule into a myriad of fine nanometric droplets, each one carrying a few fractions of the drug."

Covered with a soft shell that is insoluble in blood, and combined with the thermodynamic behaviour of opening or closing, these fascinating polymers take on some extraordinary properties that enable them to travel through the body like small spy submarines, without experiencing deterioration, and to pass through cell membranes that were previously impervious to them. These polymers may contain substances that enable them to recognize and target cancer cells.

Françoise Winnik is one of the very few professors who teaches both chemistry and pharmacy. "They are two very different worlds," she explains. "In chemistry, you can focus entirely on the scientific dimension, while in pharmacy, you have to make allowance for the human dimension. The groundrules are different. For a pure polymer chemist, which is what I have been for more than 20 years, it opens up some completely new horizons."

Researcher: Françoise Winnik
Telephone: (514) 343-6123
Funding: Natural Science and Engineering Research Council, Fonds pour la formation des chercheurs et l'aide à la recherche, American Chemical Society