基于Con A门控分子的甘露糖响应型介孔二氧化硅纳米控制释放体系
摘要
In this work, a novel delivery system based on Concanavalon A(Con A)-gated glucose-functionalized mesoporous silica nanoparticle (MSN-Glc-Con A) was constructed for the mannose-responsive controlled release. In this system, glucose was firstly modified on the surface of mesoporous silica nanoparticles (MSN) through the crosslinking reaction between glucosamine and cyanato-functionalized MSN. Con A, a lectin, was subsequently bound the functionalized glucose epitopes through multivalent carbohydrate- protein interactions, resulting in blockage of pores and inhibition of guest molecules release. In the presence of mannose, the Con A competitively bound with mannose and got away from the pore of MSN because of higher affinity for mannose. Thus, the pores were uncapped and the entrapped guest molecules were released. The physical and chemical properties of the as-synthesized MSN were characterized by transmission electron microscopy, X-ray diffraction, Fourier transform Infrared spectroscopy, Brunauer-Emmett- Teller and thermogravimetric analysis. As a proof-of-principle, [Ru(bipy)<sub>3</sub>]Cl<sub>2</sub> was selected as the model guest molecules, and the mannose-responsive loading and release of [Ru(bipy)<sub>3</sub>]Cl<sub>2</sub> have been investigated. The results demonstrate that the system had excellent loading amount (89.90 ± 7.73 μmol/g SiO<sub>2</sub>) and good mannose-responsive release behavior. Release-profile studies in MOPS buffer showed that no [Ru(bipy)<sub>3</sub>]Cl<sub>2</sub> leaked when the pore was closed and that release occurred immediately after adding mannose. The dye release percentage can over 90% after treatment with 40 mmol/L mannose for 340 min. This lectin-gated MSN delivery system is a promising candidate for therapeutic agent delivery.