Near-infrared light-responsive supramolecular nanovalve based on mesoporous silica-coated gold nanor

Mesoporous silica nanoparticles (MSNs) functionalized with molecular and supramolecular nanovalves have attracted considerable attention. A variety of stimuli have been applied to activate the nanovalves for controlled drug release. However, the most desirable one is to explore benign activation mechanisms applied to biological systems. Based on this concept, Ying-Wei Yang’s research group reported arene-based biocompatible nanovalves specifically triggered by enzymes (Chem. Commun. 2013, 49, 9033-9035), or neurotransmitters, hopefully for the treatment of Parkinson’s disease (Chem. Eur. J. 2014, 20, 2998-3004). Light activation is a more promising approach owing to the advantages of remote control and less invasiveness. Specifically, compared to ultraviolet-visible light-stimulated mechanized MSNs (Chem. Eur. J. 2012, 18, 9212-9216), near-infrared (NIR) light stimulus enables deeper penetration and less risk of damage to body tissues.

Based on our previous research findings, we constructed NIR light-responsive calixarene supramolecular nanovalve based on mesoporous silica-coated gold nanorods (AuNR@MSN). Mesoporous silicas coated on AuNRs guarantee a high drug payload and can be easily post-functionalized. Significantly, the plasmonic heating from the NIR light-stimulated AuNRs cores can decrease the host-guest binding affinity, leading to remote continuous release and “ladder” pulsatile release. The new multi-hybrid nanomaterial offers exciting prospects for non-invasive controlled drug delivery, being more effective and safer. This has just been published in the RSC journal, Chemical Science (Chem. Sci. 2014, 5, 2804-2808).