We describe nanoscale assemblies in biological materials systems.
160">We focus on effects of multivalent cations on microtubule ordering and disassembly.
Divalent cations either bundle or depolymerize paclitaxel-stabilized microtubules.
The ion concentration for depolymerization decreases with increasing atomic number.
We describe microtubule-inspired lipid cylindrical nanostructures for applications.