Mechanized Silica Nanoparticles Based on Pillar[5]arenes for On-Command Cargo Release

Graphical Mechanized silica nanoparticles, equipped with pillar[5]arene-[2]pseudorotaxane nanovalves , operate in biological media to trap cargos within their nanopores, but release them when the pH is lowered or a competitive binding agent is added. Although cargo size plays an important role in cargo loading, cargo charge-type does not appear to have any significant influence on the amount of cargo loading or its release. These findings open up the possibility of using pillar[n]arene and its derivatives for the formation of robust and dynamic nanosystems that are capable of performing useful functions.