title: Fluorescent mesoporous silica nanotubes incorporating CdS quantum dots for controlled release of ibuprofen.
abstract: Mesoporous silica nanotubes (MSNTs) and amine-functionalized MSNTs (NH(2)-MSNTs) have been successfully synthesized via a sol-gel route using needle-like CaCO(3) nanoparticles as inorganic templates and post-modification with 3-aminopropyltriethoxysilane. Subsequently, the preformed nanotubes were functionalized with blue fluorescent CdS quantum dots, as demonstrated by transmission electron microscopy and confocal laser scanning microscopy. The morphology and microstructure of the produced materials were characterized by scanning electron microscopy and N(2) adsorption-desorption measurements. A comparative study of the capacity of several kinds of nanotube materials to store ibuprofen indicated that the drug-loading amount in CdS-NH(2)-MSNTs (CdS-incorporated NH(2)-MSNTs) could reach up to 740 mg/g silica, similar to that in as-prepared MSNTs (762 mg/g silica) and NH(2)-MSNTs (775 mg/g silica). Drug release studies in simulated body fluid revealed that the loaded ibuprofen released from amine-functionalized systems at a significantly lower release rate as compared to that from amine-free systems, and the incorporation of CdS quantum dots had nearly no effect on the ibuprofen release process. Further study on the ibuprofen release from CdS-NH(2)-MSNTs in other media, i.e. borate buffer saline, pure water and normal saline, indicated that CdS-NH(2)-MSNTs are pH- and ion-sensitive drug carriers, which should facilitate controlled drug delivery and disease therapy.
authors.affiliation: Key Lab for Nanomaterials of Ministry of Education, Beijing University of Chemical Technology, Bei San Huan Dong Road 15, Beijing 100029, China.
authors.forename: Yun-Jie
authors.initials: YJ
authors.lastname: Yang
authors.forename: Xia
authors.initials: X
authors.lastname: Tao
authors.forename: Qian
authors.initials: Q
authors.lastname: Hou
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Chen
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry; D019187:Cadmium Compounds / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems; D007052:Ibuprofen / Q000737:chemistry / Q000378:metabolism; D008422:Materials Testing; D043942:Nanotubes / Q000737:chemistry*; D016062:Porosity; D045663:Quantum Dots; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013431:Sulfates / Q000737:chemistry*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001672:Biocompatible Materials; D019187:Cadmium Compounds; D004337:Drug Carriers; D013431:Sulfates; D012822:Silicon Dioxide; C037123:cadmium sulfate; D007052:Ibuprofen