Tiny light-controlled machines pull on cells
Results of collaboration of INM’s program divisions Dynamic Biomaterials and Interactive Surfaces with international partners on “Optoregulated force application to cellular receptors using molecular motors” published in Nature communications.
In their natural environment, human cells are never alone. Whether blood, skin, or nerve cells, they live together in colonies, pull on each other and jostle each other. These mechanical impulses do not remain without consequences but trigger specific biochemical processes. What are the possibilities of exerting externally controlled force on living cells? How can this force be explicitly used to control cell function? And how can the force acting on cells be measured? To get to the bottom of these questions, research teams from INM – Leibniz Institute for New Materials, Saarland University, Strasbourg University in France, and the Georgia Institute of Technology in Atlanta, USA, pooled their expertise. They have now published the result of their collaboration in the prestigious journal Nature Communications.
Experts call mechanotransduction the process when external mechanical impulses are sensed by cells and converted into biochemical signals, which in turn regulate specific properties of the cells. This process influences essential cell functions such as proliferation, movement, or programmed cell death and is crucial for tissue formation and repair. Malfunction can lead to diseases, such as diseases of the cardiovascular system, muscle atrophy, or cancer.
In their natural environment, cells generate forces using cellular protein chains and through the action of cell-internal “motors”. Inspired by these natural motors, the international project group used an artificial, purely synthetic motor and developed a special, light-controlled material for their project. This material contains a large number of tiny rotors bound between a surface and the cell receptors via polymer chains and activated by UV light. The force generated in this way can be regulated as a function of wavelength and duration of irradiation and is sufficient to generate a biochemical response via the cell receptors. In collaboration with the Center for Integrative Physiology and Molecular Medicine at the University Hospital in Homburg, it was shown, among other things, that it is possible to specifically activate special immune cells, the so-called T-cells, utilizing the light-controlled motors.
Professor Aránzazu del Campo, Scientific Director of INM and Head of the Program Division Dynamic Biomaterials at INM, explains, “With the new light-driven material, it is possible to exert a controlled force on cells – without the use of complicated devices. The flexible material design will allow cells to be studied in their natural environment in the future to better understand force-driven biochemical processes in cells and develop active biomaterials.”
In order to measure the force that these motors exert on cells, INM’s Interactive Surfaces program division developed a new method that enables force measurements at a high throughput rate. For this purpose, the motors were not bound to cells but between microparticles and a surface in a tiny flow channel. By changing the channel flow, it was possible to determine the maximum force against which the remotely controlled motors could still pull the microparticles. Thus, for the first time, a measurement could be performed on hundreds of light-sensitive molecular motors simultaneously.
Your contact person:
Prof. Dr. Aránzazu del Campo
Scientific Director of the INM and
Head of the Program Division Dynamic Biomaterials
Phone ++49 (0)681 9300 510
Zheng, Y., Han, M.K.L., Zhao, R. et al. Optoregulated force application to cellular receptors using molecular motors. Nat Commun 12, 3580 (2021).