Date: 5th February 2019
3D cell cultures offer us an artificial environment in order to study living cells and their behaviour in response to their environment. They are crucial in understanding how to synthesis artificial systems, such as the cells themselves, but also the complexity required to design tissues and organs. Hydrogels are useful tools for creating the microenvironment of cells and tissues and are being increasingly used in 3D cell culture applications. The behaviour of many cells responds to the environment in which it is residing, therefore can differ depending whether cultured in soft or stiffer hydrogel. However, once the culture has commenced it is difficult to change the properties of the gel. Thus unlike in its natural environment which is constantly changing, the cells in culture are exposed to a static, irreversible condition.
Now scientists from the Netherlands have recently described the hierarchical mechanics of ultra-responsive hybrid hydrogels in their work published in the Nature journal. These hydrogels are composed of two synthetic networks, one semi-flexible and stress-responsive, the other flexible and thermo responsive. The combination creates a very responsive, reversible movement, which may be able to simulate the cytoskeleton components in synthetic cells. Furthermore, relatively large changes can be achieved with small stimuli, in this case temperature.
Looking towards the future it is likely that this system can be adapted to mimic true muscle movements, however this would have to be in a unidirectional orientation which isn’t currently the case. However, if this can be achieved it will be a significance advancement for the likes of tissue engineering. If applied to synthetic cell systems this could act as a dynamically switchable cytoskeletal component, triggered by a small thermal (or other) cue.
de Almeida, P., M. Jaspers, S. Vaessen, O. Tagit, G. Portale, A. E. Rowan and P. H. J. Kouwer (2019). “Cytoskeletal stiffening in synthetic hydrogels.” Nature Communications 10(1): 609.