Endosomal escape kinetics of mesoporous silica-based system for efficient siRNA delivery

The strategy of encapsulating small interference RNA (siRNA) into the mesopores enables mesoporous silica nanoparticles (MSNs) to be an attractive material for siRNA delivery. Nevertheless, the gene silencing efficiency mediated by this sort of vehicles has not been systematically investigated yet. In this work, through quantifying gene silencing efficiency by flow cytometry (FCM) and performing intracellular tracking by confocal laser scanning microscopy (CLSM), we found that the RNA interference (RNAi) efficiency mediated by MSNs-based delivery vehicles was strongly dependent on their endosomal escape capability. Thereafter, we investigated the correlation between the gene knockdown efficiency and the endosomal escape kinetics of such carriers. The results indicated that highly efficient MSNs-based siRNA delivery vectors must possess the capability of initiating effectively endosomal escape before the degradation of their packaged siRNA in endolysosomes.