Nanovalves for Mesoporous Silica Particles Based on Polypseudorotaxane Motif

摘要

Controlled release systems have attracted a great attention due to their applicability in the area of drug delivery. To date, a diverse class of organic carriers, such as micelles, liposomes, and polymeric nanoparticles, have been investigated for their utility as delivery systems. However, organic carriers such as micelles suffer from poor stability due to biochemical attack. Recently, amorphous mesoporous silica particles were suggested as useful carriers because of their stability, controllable pore diameter, and biocompatibility. Several groups reported on controlled release systems using mesoporous silica. Fujiwara et al. described the photo-induced release of drug molecules from coumarin-functionalized MCM-41. The thermoresponsive release system was demonstrated by using a mesoporous material modified with poly(N-isopropyl acrylamide). The pH-responsive release systems based on mesoporous silica were reported by using polyelectrolyte motif. Stoddart et al. reported the redox-controlled nanovalve based on mesoporous silica materials with the pseudorotaxane. More recently, a base-triggered controlled release system was demonstrated. However, cyclodextrin (CD)-rotaxane-based pH responsive system on silica materials has not been reported.