I think the problem is the nanocrystals are about 500 nm long, of the order of 100th the width of a human hair, so it's hard actually build much with them. From another article:

>Calculations using precise models based on the atomic structure of cellulose show the crystals have a stiffness of 206 gigapascals

>"It is very difficult to measure the properties of these crystals experimentally because they are really tiny," Zavattieri said. "For the first time, we predicted their properties using quantum mechanics." (https://phys.org/news/2013-12-cellulose-nanocrystals-green-m... )

So they are strong in theory but too small to actually pull on the ends.

There's some recent research mixing them in 3d printer inks http://www.3ders.org/articles/20170531-empa-researchers-deve...