Mesoporous SBA-15 end-capped by PEG via L-cystine based linker for redox responsive controlled release

A unique redox responsive system for glutathione (GSH) triggered controlled release was prepared by modifying the mesoporous SBA-15 with L-cystine ester linked mPEG chains, in which the former was served as the nanoreservoir of guest molecules and the latter was applied as gatekeepers to block the mesopores. The disulfide bond in L-cystine ester can be effectively cleaved by redox reaction under glutathione of cancer cell level, and then resulting in the release of guests encapsulated in the pores. Fluorescein dye as the model drug was loaded into the mesoporous silica nanoparticles (MSNs) and released in PBS with 10 mM GSH and without GSH respectively to test the controlled release properties of the MSNs using UV-Vis spectra as the detector. The results showed that fluorescein dye in PBS with 10 mM GSH was released much more rapidly. Compared with such a controlled release system based on MCM-41, the SBA-15 based system showed a distinctive release behavior. The MSNs synthesized from SBA-15 can be used as an effective drug controlled release system for biomedical applications, especially for long-term drug delivery. (C) 2013 Elsevier Inc. All rights reserved.