It will be fun to discuss something like this from within The Design Matrix:

Microtubules, essential structural elements in living cells, grow stiffer as they grow longer, an unexpected property that could lead to advances in nano-materials development, an international team of biophysicists has found.

[…]

To the surprise of the scientists, they found that the longer the filament, the more rigid it became.

Florin and his coauthors attribute the microtubules’ unique properties to their molecular architecture. The nanometer-sized filaments are hollow tubes made of tubulin proteins that bind to each other in ways that give them the ability to be both flexible and stiff. Flexibility is important for microtubules as they grow and change in cells, while rigidity is important when cells need support.

“Microtubules are optimally designed to give the maximum of mechanical performance at a minimum cost for the cell,” said Francesco Pampaloni, a physical chemist at EMBL.

The new finding about the microtubules’ properties could provide insights into using the filaments as models for the development of nano-materials.