Patrick Couvreur, Nano-oncologist
This year's recipient of the Host Madsen Medal, Couvreur is no newcomer to the field of nanomedicine. He was the first to develop nanometric capsules able to penetrate cells to deliver medicine and is now working on nanoparticles that can target cancerous cells directly. No small affair.
Patrick Couvreur is an emblematic figure of medical nanotechnology. And if he finds the recent focus of attention on this field somewhat amusing, it's for good reason: He has been “practicing” nanotechnology since 1975. The Belgian-born director of the “Physico-chimie, pharmacotechnie, biopharmacie” unit1 at Châtenay-Malabry has long worked at the junction of basic research and the pharmaceutical industry. It has won him this year's prestigious Host Madsen Medal, awarded by the International Pharmaceutical Federation (FIP), a fitting recognition for this specialist in nanomedicines whose head is brimming with projects. “My real dream is to develop an effective anticancer medicine and to create a 'drug discovery institute' in the
Ile-de-France region, to give France international visibility in this field,” states Couvreur. And this area of activity is one he knows well, since he is already heavily involved in the international Médicen Paris Région competitiveness cluster.2
© H. Raguet/CNRS Photothèque
During his adolescence, the age of emerging vocations, he was more interested in sports than in science. “Being an average student, my parents sent me to the Jesuit University in Namur after my baccalaureate, where I was lucky enough to meet a professor who helped me discover and enjoy science.” The top pharmacy graduate of his year, he then completed a thesis on tablets. It is the encounter with the laboratory of Professor De Duve–winner of the 1974 Nobel Prize in Medicine–and with his “dream” medical team that led him to conceive his ground-breaking idea: to create “microforms” that would help molecules penetrate into cells. His meeting with the Swiss pioneer of nanoparticles, Peter Speiser, was a turning point in his career. In 1977, Couvreur moved to Zurich with his family for a year of “high-flying science.” There, he became the first to develop nanometric capsules capable of penetrating cells to deliver medicine. The initial polymer used was non-biodegradable and could not be used on humans. But the development of “cyanoacrylates,” biodegradable surgical adhesives, overcame that obstacle. Couvreur used these new polymers to develop nanoparticles, thus paving the way for the creation of nanomedicines.
At the time, he was associate professor at Louvain (Belgium), working on a teaching thesis. Francis Puisieux, a professor on his thesis committee, noticed his creative mind and offered him a position at the Paris-Sud University. After 23 years in France, he has perfectly adapted to his host country. “In the early days, my children didn't escape the French jokes about Belgians. But I felt I had finally found my linguistic home, getting away from the Flemish rejection of the French language.”
His team quickly had its first success with the efficient action of certain nanoparticles on hard-to-treat hepatic cancers. This, in 1997, spurred the creation of the Bioalliance Company, in charge of carrying out a clinical trial on hepatocarcinoma. But Couvreur is quite clear on his relationship with the pharmaceuticals industry. “Our relations are based on exchanges, on one condition: never 'sell out.' I only accept industrial contracts in conceptual fields innovative enough to justify CNRS involvement.”
During this time, he also created the “Therapeutics Innovation” doctoral school. For Couvreur, this is a means of “bridging the gap between students and industry.” It is precisely with one of his research students that he recently paved the way for third generation nanoparticles, capable of specifically targeting cancerous cells. After months of failed attempts at encapsulating the anticancer agent gemcitabine in nanoparticles, tests were conducted on the linkage of this molecule with squalene, a very compact lipid. This was a complete success as the mixture spontaneously formed nanoassemblies in water. When incubated with human tumors, the mixture has proven to be ten times more effective than the drug alone. A “squalenoylated” nanomedicine platform has been set up at Paris Biotech (Cochin Faculty of Medicine) for further research on this compound, and a start-up company will soon be responsible for the pharmaceutical development of this discovery.
1. CNRS / Université Paris-XI.