Professor Carole Bourquin receives the Egon Naef Foundation 3R Prize 2019 in recognition for the development of a new in vitro technique that reduces by 20% the number of mice needed for nanoparticle research in immunotherapy.

Nanoparticles allow drugs to be transported to selected sites in our bodies. By targeting the lymph nodes, it is possible to specifically stimulate the immune system, a promising approach to fight cancer. To choose appropriate nanoparticles, researchers test their behavior in animals. Carole Bourquin’s team from the University of Geneva (UNIGE) has developed a technique that makes it possible to perform a first in vitro screening of the nanoparticles. Only the best performers are then tested in animals. This method, which has been awarded the 2019 Egon Naef Foundation Prize for In Vitro Research, reduces the number of mice used in nanoparticle research for immunotherapy.

Immunotherapy research aims to stimulate the immune system to recognize and destroy cancer cells. Nanoparticles can improve treatment effectiveness by delivering the drug in the human body to the exact site where it will trigger the immune response, in the lymph nodes. The most efficient nanoparticles for transporting and releasing drugs into the lymph nodes must be captured by immune cells to be transported to the lymph nodes; they must not be toxic to cells; and they must not activate the immune system against themselves. Until now, nanoparticles were systematically tested in mice to ensure that they meet these three criteria.

The team in Geneva incubated the nanoparticles with immune cells grown in the laboratory. Then it was assessed by flow cytometry whether they had captured nanoparticles and whether or not the cells were in a state of activation. To date there is no non-animal method to predict whether the nanoparticles are transported to the lymph nodes, but the screening method can select the most promising particles before animal testing commences and so reduce the number of animals required for testing.