Reactive oxygen species-sensitive thioketal-linked mesoporous silica nanoparticles as drug carrier for effective antibacterial activity

Mesoporous silica nanoparticles (MSNs) carrying gatekeepers that are stimuli-responsive are widely investigated for the controlled delivery of drug at target sites. In this study, thioketal (TK) functionalized methoxy poly(ethylene glycol) (mPEG-TK) as ROS-responsive gatekeeper is used to modify MSNs and leads to a reactive oxygen species (ROS)-responsive delivery for antibacterial drug. Vancomycin (Van) was taken as the antibacterial drug and then physically encapsulated into the surface amino functionalized MSNs (N-MSNs). Subsequently, mPEG-TK was surface immobilized. Van loaded N-MSNs with surface modification of mPEG-TK (Van-mPEG-TK-MSNs) presented approximately 21% release of Van in a physiological environment in 36 h. With H2O2 increasing in the medium, the release rate of Van from Van-mPEG-TK-MSNs was significantly up-regulated following gatekeepers' disintegration. When Van-mPEG-TK-MSNs was applied in vivo, the infected site was fully cleared after 14 days and the tissue was free of infection. On the whole, the mentioned results suggested that Van-mPEG-TK-MSNs could act as a potential antimicrobial. This study can broaden MSNs' applications and advance the development of novel antibacterial agents. (c) 2020 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).