Gated Mesoporous Silica Nanocarriers for Hypoxia-Responsive Cargo Release

Mesoporous silica nanocarriers (MSNs) are appealing in terms of their large cavity surface area and high loading capacity, but they have been suffering from premature cargo release. Herein, we report a gated smart MSN that is sensitive to low oxygen concentration (i.e., hypoxia) via taking advantage of the superior electron-accepting ability of the azobenzene moiety. The azobenzene polymer was employed as the responsive gate-keeper that was deposited on the MSN surface, followed by coating with amphiphilic Pluronic F68 for steric stabilization. The obtained nanocarriers were less than 200 nm. The