Figure 8.

Schematic illustration of stimuli responsive nanovalve-gates on mesoporous silica nanoparticles. (a-c) cyclodextrin gated mesoporous silica surface and their cargo release pattern reproduced with permission from ACS Nano 2015, 9, 11, 10778 published by American Chemical Society, (d-g) cross-linked network on mesoporous silica nanoparticles and molecular design of sodium alginate (SA) along with release kinetics and microscopic images, reproduced from Front. Chem. 7:59. doi: 10.3389/fchem.2019.00059 an open-access article under the terms of the Creative Commons Attribution License (CC BY), (h-j) nanopiston mechanism of phosphonate covered mesoporous silica through acid-cleavable acetal bond, reproduced with permission from J. Am. Chem. Soc. 2010, 132, 37, 13016 published by American Chemical Society.