title: Hybrid mesoporous silica nanoparticles with pH-operated and complementary H-bonding caps as an autonomous drug-delivery system.
abstract: Mesoporous silica nanoparticles (MSNPs) are functionalized with molecular-recognition sites by anchoring a triazine or uracil fragment on the surface. After loading these MSNPs with dyes (propidium iodide or rhodamine B) or with a drug (camptothecin, CPT) they are capped by the complementary fragments, uracil and adenine, respectively, linked to the bulky cyclodextrin ring. These MSNPs are pH-sensitive and indeed, the dye release was observed at acidic pH by continuously monitored fluorescence spectroscopy studies. On the other hand, no dye leakage occurred at neutral pH, hence meeting the non-premature requirement to minimize side effects. In vitro studies were performed and confocal microscopy images demonstrate the internalization of the MSNPs and also dye release in the cells. To investigate the drug-delivery performance, the cytotoxicity of CPT-loaded nanoparticles was tested and cell death was observed. A remarkably lower amount of loaded CPT in the MSNPs (more than 40 times less) proved to be as efficient as free CPT. These results not only demonstrate the drug release after pore opening under lysosomal pH, but they also show the potential use of these MSNPs to significantly decrease the amount of the administered drug.
authors.affiliation: Institut Charles Gerhardt Montpellier UMR-5253 CNRS-UM2-ENSCM-UM1, Ecole Nationale Supérieure de Chimie de Montpellier, 8 rue de l'école normale, 34296 Montpellier Cedex 05 (France); Department of Chemistry and Biochemistry, University of California Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095 (USA).
authors.forename: Christophe
authors.initials: C
authors.lastname: Théron
authors.forename: Audrey
authors.initials: A
authors.lastname: Gallud
authors.forename: Carole
authors.initials: C
authors.lastname: Carcel
authors.forename: Magali
authors.initials: M
authors.lastname: Gary-Bobo
authors.forename: Marie
authors.initials: M
authors.lastname: Maynadier
authors.forename: Marcel
authors.initials: M
authors.lastname: Garcia
authors.forename: Jie
authors.initials: J
authors.lastname: Lu
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Tamanoi
authors.forename: Jeffrey I
authors.initials: JI
authors.lastname: Zink
authors.forename: Michel
authors.initials: M
authors.lastname: Wong Chi Man
mesh_terms: D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D061986:MCF-7 Cells; D018613:Microscopy, Confocal / Q000379:methods; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*; D012822:Silicon Dioxide / Q000008:administration & dosage / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry; D014498:Uracil / Q000737:chemistry
chemical_list: D014227:Triazines; D014498:Uracil; D012822:Silicon Dioxide
keywords: drug delivery; mesoporous hybrid silica nanoparticles; molecular recognition; pH-sensitivity; sol-gel