Shear-thickening fluids for cryopreservation.

In regenerative and transplantation medicine medicine a bottleneck limiting progress is that tissue engineered

constructs cannot be manufactured on demand. Cryopreservation aims to overcome this problem, however

whilst success has been achieved with cell suspensions, successful scale up of construct size has remained

elusive. No methods exist that can protect complex biomasses from the severe stress they encounter during

cooling and warming from liquid nitrogen (-196°C). We propose a new method, where non-Newtonian, shear-

thickening fluids can be used to improve operational performance of cryopreservation. Shear thickening fluids

are materials whose viscosity increases with shear stress, for example vibration. With the correct level of

vibration, the material can change from a liquid to a solid instantly. We propose this as an effective material for

extremely low temperature biological preservation. At the storage temperature, shear stress would be stopped

as the material would remain solid (vitrified) due to the low temperatures. The shear-thickening materials

make the process completely reversible.