Azobenzene Polyesters Used as Gate-Like Scaffolds in Nanoscopic Hybrid Systems

作者：Bernardos Andrea; Mondragon Laura; Javakhishvili Irakli; Mas Nuria; de la Torre Cristina; Martinez Manez Ramon^*; Sancenon Felix; Barat Jose M; Hvilsted Soren; Orzaez Mar; Perez Paya Enrique; Amoros Pedro

来源：Chemistry - A European Journal, 2012, 18(41): 13068-13078.

DOI：10.1002/chem.201200787

• azo compounds
• drug delivery
• enzymes
• mesoporous materials
• polyesters

The synthesis and characterisation of new capped silica mesoporous nanoparticles for on-command delivery applications is reported. Functional capped hybrid systems consist of MCM-41 nanoparticles functionalised on the external surface with polyesters bearing azobenzene derivatives and rhodamine B inside the mesopores. Two solid materials, Rh-PAzo8-S and Rh-PAzo6-S, containing two closely related polymers, PAzo8 and PAzo6, in the pore outlets have been prepared. Materials Rh-PAzo8-S and Rh-PAzo6-S showed an almost zero release in water due to steric hindrance imposed by the presence of anchored bulky polyesters, whereas a large delivery of the cargo was observed in the presence of an esterase enzyme due to the progressive hydrolysis of polyester chains. Moreover, nanoparticles Rh-PAzo8-S and Rh-PAzo6-S were used to study the controlled release of the dye in intracellular media. Nanoparticles were not toxic for HeLa cells and endocytosis-mediated cell internalisation was confirmed by confocal microscopy. Furthermore, the possible use of capped materials as a drug-delivery system was demonstrated by the preparation of a new mesoporous silica nanoparticle functionalised with PAzo6 and loaded with the cytotoxic drug camptothecin (CPT-PAzo6-S). Following cell internalisation and lysosome resident enzyme-dependent gate opening, CPT-PAzo6-S induced CPT-dependent cell death in HeLa cells.

• 出版日期2012-10