On May 14th, a new innovative technology for quantifying 3D biological forces developed by Professor Wang Ning and his team was published on the international authoritative journal Nature Comminications.
The paper entitled as Quantifying Compressive Forces Between Living Cell Layers and Within Tissues Using Elastic Round Microgels is co-authored by the Ph.D students including Erfan Monhagheghian (from UIUC), Luo Junyu, Chen Junjian and post doctorate Chen Junwei of College of Life Science and Technology. Prof. Wang ning is the senior corresponding author.
Recent years, researchers have found that mechanical signals play an important role in the growth, development, and differentiation of cells. However, a huge problem has plagued the scientific community on how to quantify biological forces and study their effects on cells, tissues, and even organs. Scientists have developed the method for quantifying 2D biological forces in vitro many years ago, but no method for quantifying 3D biological forces in vivo.
In 2009, Wang Ning proposed a new concept of MechanoBioMedicine. Biodynamic medicing mainly uses the basic principles of mechanics and engineering to study the mechanical mechanism of life activities, and develops new technologies that can be used in vitro and in vivo to regulate the physiological microenvironment, which will achieve the aims of early diagnosing, treatment and cure of some complicated diseases. Biological force is a kind of electromagnetic force, generated by living cells internal myosin II.
An inspiration came to Professor Wang Ning few years ago that the uniform elastic micro-spheres (Elmer Round Microgel, ERMG) can quantify 3D biological forces. Therefore, they made uniform elastic micro-spheres with similar cell size by self-designed micro-fluidic chip and elastic alginate polymers. And the diameter, mechanical properties, chemical properties and cell adhesion properties of each elastic micro-sphere are all the same. Besides, they added a number of fluorescent nanoparticles to the elastic micro-spheres to quantify the deformation of the elastic spheres, from which the biological forces were calculated. Experiments show that cells generate 3D normal stress and shear force to these elastic micro-spheres, which are compatible with organisms and have no toxic or any side effects, after its adhesion with living cells. According to theoretical calculations, simulation experiments and cell experiments, researchers found that 3D biological forces can be quantified by quantification of the 3D deformation of elastic microspheres and its knowable elastic modulus.
In experiments of animals in vivo, researchers found that cells in different parts produced different 3D biological forces at different times during the early embryonic development of zebra fish. These findings lay a solid foundation for future research on how biological forces affect the structural and functional embryonic development of animals in vivo.
By using this new technology, Professor Wang Ning and his team found that malignant tumor regenerating cells (tumor stem cells) proliferated in a 3D soft matrix, that is, when these cancer cell clones gradually became larger, the compressive stress in the clones did not increase. And this phenomenon is completely different from the proliferation response of normal mesenchymal stem cell clones. The finding shows that the 3D biological forces generated by malignant tumor are totally different from that generated by normal stem cells.