title: Azobenzene polyesters used as gate-like scaffolds in nanoscopic hybrid systems.
abstract: 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.
authors.affiliation: Centro de Reconocimiento Molecular y Desarrollo Tecnológico, Unidad Mixta Universidad Politécnica de Valencia, Universidad de Valencia, Camino de Vera s/n, 46022 Valencia, Spain.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bernardos
authors.forename: Laura
authors.initials: L
authors.lastname: Mondragón
authors.forename: Irakli
authors.initials: I
authors.lastname: Javakhishvili
authors.forename: Núria
authors.initials: N
authors.lastname: Mas
authors.forename: Cristina
authors.initials: C
authors.lastname: de la Torre
authors.forename: Ramón
authors.initials: R
authors.lastname: Martínez-Máñez
authors.forename: Félix
authors.initials: F
authors.lastname: Sancenón
authors.forename: José M
authors.initials: JM
authors.lastname: Barat
authors.forename: Søren
authors.initials: S
authors.lastname: Hvilsted
authors.forename: Mar
authors.initials: M
authors.lastname: Orzaez
authors.forename: Enríque
authors.initials: E
authors.lastname: Pérez-Payá
authors.forename: Pedro
authors.initials: P
authors.lastname: Amorós
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D002166:Camptothecin / Q000737:chemistry* / Q000633:toxicity*; D016503:Drug Delivery Systems; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*; D011091:Polyesters / Q000737:chemistry*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; C509968:MCM-41; D011091:Polyesters; D012822:Silicon Dioxide; C009850:azobenzene; D002166:Camptothecin