Researchers have discovered a new geometrical shape while studying the structure of the cells that line our skin and organs.
Nature never ceases to amaze us with the ingenuity and organisation it displays with the implementation of its structures. One illustration of nature’s prowess in bio-engineering lies in the architecture of animal tissues, especially of the so-called epithelial cells, which line our skin and organs. A new study reveals that they can adopt a form that neither mathematics nor biology has been able to describe thus far.
Journey to the centre of epithelial cells
Researchers have long believed that these cells, compacted against each other within tissues, have the appearance of columns or bottles. However a new study published in Nature Communications reveals an entirely different and undeniably fascinating reality. The key is the discovery of a new geometrical form, previously unknown to biologists and mathematicians.
A new geometrical form: the scutoid
This shape which was first discovered through computer models using the Voronoi diagram, a model used in many areas to better understand how geometrical shapes are organised. ‘The results observed during the modelling process were strange,’ says co-author Javier Buceta, associate professor of bioengineering at Lehigh University.
‘Our model predicted that as tissue curvature increased, columns and bottles were not the only shapes that cells could develop into. In order to minimise the energy requirements and maximise the stability of the structure against organ torsion and curvature, the cells can indeed adopt a shape that researchers observed for the very first time, the scutoid.
‘To our surprise, this new shape didn’t even have a mathematical name! It’s not everyday someone has the opportunity to name a new shape,’ he continues. The researchers chose to name the new structure a scutoid, in reference to the scutellum which constitutes the posterior part of the thorax on an insects back (easily noticeable on beetles, on them it is in the shape of a diamond).
When theory meets reality
To verify the predictions from the model, the team then analysed the structure of the tissues of several animals. As a result, when looking through a confocal microscope they found the scutoid there too! An incredible moment for the researchers as they saw their theory present in the real world. ‘We have discovered nature’s solution to guarantee an effective epithelial curvature,’ says Buceta.
Based on a biophysical approach, researchers say that such a shape would improve the structural stability and energy efficiency of the organisation of the epithelial cells. This discovery could offer new insights into the development of tissue engineering. ‘In addition to this fundamental aspect of morphogenesis, the ability to design tissues and organs in the future is critically dependent on the ability to understand and then control the three-dimensional organisation of cells,’ the team concluded.