Humans have about 1000 billion immune cells. Some of them patrol the blood and are summoned by messenger substances to wherever there is a fire. Masses of immune cells, for example, act as specialized scavenger cells, so-called macrophages, and go wherever infectious agents invade or foreign objects interfere. Tumors, however, have the ability to evade macrophage attacks: They send out signals that literally rob the phagocytes of their appetite.

While macrophages need to be "awakened" to fight tumors, they are too active in other disease processes, such as chronic wounds. Empa researchers from the Particles-Biology Interactions, Biointerfaces and Biomimetic Membranes and Textiles labs in St. Gallen are therefore joining forces to sensitize the macrophages to match the disease process in the body.

For this purpose, active substances are to be embedded in a hydrogel, a scaffold made of a biodegradable polymer, which attract macrophages and "reprogram" them appropriately. Biophysicist Katharina Hast recently started her doctoral thesis within the project. The Empa researcher is convinced that the strategy of introducing nanoparticle active substances via a smart material has several advantages: "The hydrogel should be able to influence macrophages precisely and efficiently. This should also make it possible to reduce the side effects of treatments, she says.

Empa's Zukunftsfonds is looking for private donors for exceptionally talented young researchers and for outstanding research projects that are not (yet) supported elsewhere. The Vaduz-based Uniscientia Foundation is funding the present project.