Graphene, a new two-dimensional carbon material, is a rising star of physics, chemistry and materials science. In this work, we report the recent experimental researches on the Raman spectra and the temperature-depend...Graphene, a new two-dimensional carbon material, is a rising star of physics, chemistry and materials science. In this work, we report the recent experimental researches on the Raman spectra and the temperature-dependent features of graphenes and car- bon nanoscrolls, which are evolved from graphene and have an open tubular structure. The layer-dependent Raman enhancing characteristics of n-layer graphenes for crystal violet, and the thickness-dependent morphologies of gold on n-layer graphenes are also systematically investigated. Meanwhile, the aggregations of ferromagnetic and paramagnetic atoms at edges of gra- phenes and graphite are observed and the mechanisms are discussed.展开更多
Multifunctional nanoparticles combining diagnostic and therapeutic agents into a single platform make cancer theranostics possible and have attracted wide interests in the field. In this study, a multifunctional nanoc...Multifunctional nanoparticles combining diagnostic and therapeutic agents into a single platform make cancer theranostics possible and have attracted wide interests in the field. In this study, a multifunctional nanocomposite based on dextran and superparamagnetic iron oxide nanoparticles （SPIO） was prepared for drug delivery and magnetic resonance imaging （MRI）. Amphiphilic dextran was synthesized by grafting stearyl acid onto the carbohydrate backbone, and micelle was formed by the resulted amphiphilic dextran with low critical micelle concentration at 1.8 mg L^-1. Doxorubicin （DOX） and a cluster of the manganese-doped iron oxide nanoparticles （Mn-SPIO） nanocrystals were then coencapsulated successfully inside the core of dextran micelles, resulting in nanocomposites with diameter at about 100 nm. Cell culture experiments demonstrated the potential of these Mn-SPIO/DOX nanocomposites as an effective multifunctional nanoplat- lk）rm for the delivery of anticancer drug DOX with a loading content （DLC） of 16 %. Confocal laser scanning microscopy reveals that the Mn-SPIO/DOX had excellent internalization ability against MCF-7/Adr cells after 2-h labeling compared with flee DOX.HCI. Under a 3.0-T MRI scanner, Mn-SPIO/ DOX nanocomposite-labeled cells in gelatin phantom show much darker images than the control. Their transverse relaxation （T2） rate is also significantly higher than that of the control cells （33.9 versus 2.3 s^-1）. Our result offers an effective strategy to treat MCF-7/Adr at optimized low dosages with imaging capability.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 10774032, 90921001, 50825206)
文摘Graphene, a new two-dimensional carbon material, is a rising star of physics, chemistry and materials science. In this work, we report the recent experimental researches on the Raman spectra and the temperature-dependent features of graphenes and car- bon nanoscrolls, which are evolved from graphene and have an open tubular structure. The layer-dependent Raman enhancing characteristics of n-layer graphenes for crystal violet, and the thickness-dependent morphologies of gold on n-layer graphenes are also systematically investigated. Meanwhile, the aggregations of ferromagnetic and paramagnetic atoms at edges of gra- phenes and graphite are observed and the mechanisms are discussed.
基金supported by the National Basic Research Program of China(2013CB933903)the National Key Technology Research and Development Program(2012BAI23B08)+1 种基金the National Natural Science Foundation of China(51173117)the Scientific Research Start-up Fund of Kunming University of Science and Technology(KKSY201305089)
文摘Multifunctional nanoparticles combining diagnostic and therapeutic agents into a single platform make cancer theranostics possible and have attracted wide interests in the field. In this study, a multifunctional nanocomposite based on dextran and superparamagnetic iron oxide nanoparticles （SPIO） was prepared for drug delivery and magnetic resonance imaging （MRI）. Amphiphilic dextran was synthesized by grafting stearyl acid onto the carbohydrate backbone, and micelle was formed by the resulted amphiphilic dextran with low critical micelle concentration at 1.8 mg L^-1. Doxorubicin （DOX） and a cluster of the manganese-doped iron oxide nanoparticles （Mn-SPIO） nanocrystals were then coencapsulated successfully inside the core of dextran micelles, resulting in nanocomposites with diameter at about 100 nm. Cell culture experiments demonstrated the potential of these Mn-SPIO/DOX nanocomposites as an effective multifunctional nanoplat- lk）rm for the delivery of anticancer drug DOX with a loading content （DLC） of 16 %. Confocal laser scanning microscopy reveals that the Mn-SPIO/DOX had excellent internalization ability against MCF-7/Adr cells after 2-h labeling compared with flee DOX.HCI. Under a 3.0-T MRI scanner, Mn-SPIO/ DOX nanocomposite-labeled cells in gelatin phantom show much darker images than the control. Their transverse relaxation （T2） rate is also significantly higher than that of the control cells （33.9 versus 2.3 s^-1）. Our result offers an effective strategy to treat MCF-7/Adr at optimized low dosages with imaging capability.
