Synthesis and characterization of core-shell mesoporous silica nanoparticles with various shell thickness as indomethacin carriers: In vitro and in vivo evaluation

A series of core-shell mesoporous silica nanoparticles (MSN@Ms) were successfully prepared with reducing response environmental stimuli TEOS-BTES as a shell and mesoporous silica nanoparticles (MSN) as a core. The results demonstrated that both MSN and MSN@Ms possessed spherical mesoporous structure and good porosity. Moreover, the size of particles and thickness of shell can be regulated by BTES amount. Besides, Indomethacin (IMC) could be loaded into the silica carriers in amorphous state, and the IMC loading amount was positively correlated with the pore volume. The release profile illustrated that the TEOS-BTES shell coating on the surface of MSN could act as reducing activatable trigger to achieve control release, while MSN provided enough space to encapsulate IMC with high loading. It was also found that MSN and MSN@Ms could be degraded in vitro. Furthermore, both IMC-MSN and IMC-MSN@M2 could reduce the gastric mucosa irritation and improve the bioavailability of IMC, and IMC-loaded MSN had a higher bioavailability than IMC-loaded MSN@M2.